Don,

Since we had gotten more and more off the original topic of "Mills and
Drills" I didn't want to irritate anyone further and so started this
thread to address what you told me.

And -- it is still not at all clear that you *can* do SS --
depending on your choice of *which* of many Stainless Steels. Some of
those are very nasty to work.

I originally wanted to go with 316L stainless steel when I was
considering a larger lathe, but I'm now thinking more in terms of
Aluminum and 303 stainless steel. But the following are details of the
part of this project that *must* be made of 316L.S.S.

1.00" of a 2-1/2" long, 7/16" diameter rod must be turned down to 1/4"
diameter. The 7/16" diameter end will be threaded so it can be screwed
into a 316L stainless steel ball-knob. The 1/4" diameter end will fit
into a 316L S.S. sleeve that will be 5/8" long, leaving a 3/8" area in
the assembly that is 1/4" diameter. To keep this sleeve on the main rod
I will need to drill a 1/8" hole all the way through the sleeve *and*
the rod inside so I can slide a tight fitting 1/8" Delrin rod to lock
them in place.

I don't know what the milling attachment for the lathe will allow me to
do,

Not much, in SS. SS needs lots of rigidity, and a milling
attachment in a lathe normally lacks a lot of rigidity compared to a
true milling machine.

Even though it's a "baby-step" I'm considering the Micro-Mark mini-mill
to compliment the lathe.(Perhaps there will be compatible tooling
between the two). I'm just wondering if the milling attachment for the
lathe would make this unnecessary.(At least at this low level).

but some things below may require totally different tools.
Nevertheless, I still want to see how much I can get done on a lathe
before I really need a dedicated milling machine.

I will need to: Bore 1/4" wide, 1/4" deep circular grooves in S.S.

In flat SS, or in round stock? It sounds as though you are
planning to do this in flat workpieces (races for balls, I suspect, from
earlier postings you have made). And I presume that this means round
profiles to the groove as well as a circle form to the groove.

Actually, this would be a "trench" with a square profile.(But it's one
job I mentioned that I may not have to do).

To do this on a lathe, you will need a form tool corresponding
to the shape you need to produce, and that is going to be nasty to use.
A quick calculation says that a 1/4" wide groove will need the tool
cutting on a 0.3927" wide surface. I would not really like to do this
on my 12" lathe, let alone your little 7" (IIRC) lathe. Most of my
tools cut on (at most) a 1/8" (0.125") long edge before the power of my
1-1/2 HP motor gets to struggling.

Then I definitely wouldn't try it on the Microlux lathe. :-)

And you've been talking (in another thread) about rigidity not
mattering as much on a small lathe. When you do something like this in
Stainless Steel, you're going to need every bit of rigidity you can
find. If you don't have the rigidity to take a reasonable cut, and the
power to keep it going, the SS is going to work harden and then fight
you all the way.

Yes. But just to reiterate, stainless steel is the extreme. And thanks
to your advice I'm using it as a yardstick to determine what is and
isn't plausible with the MM lathe.

On a *mill*, you would want a 1/4" ball-end mill, and a rotary
table to turn the workpiece under the mill.

And -- your talk of 1/4" deep as well as 1/4" wide says that the
top of the balls will not show above the surface, so it will offer no
bearing operation -- even if by some miracle you get a smooth enough
finish to have the groove act as a reasonable bearing race. Your groove
should not be that deep.

If I did end up doing this I would place a 1/16" Delrin "floor" inside
the groove.(But as it stands now, I'm going with he Delrin "cup" idea
so the bearings will touch only Delrin and not metal).

Turn down 7/16" diameter S.S. rods to 1/4".

How long? If the length is more than four times the diameter
(final diameter, not starting diameter) and you are turning in a chuck,
you will need a "traveling steady rest" (also called a "follower rest").
If it is more than double that, you will need the traveling steady even
for workpieces turned between centers. (And you will need a ball
bearing "live" center in the tailstock.)

MM sells a live center set for $92.65(#83185), and a live ball bearing
center for $12.95(#82509). I'm also looking at that steady rest for
$31.45(#82503) and the follower rest (#82504) on the Micro-Mark
mini-lathe page, but it doesn't say "traveling".

And again -- which alloy of SS?

316L

Thread S.S. rods to fit rod-ends, knobs, ect.

This also calls for a lot of rigidity. You will need either HSS
toolbits ground to the proper angles for the threading (60 degrees for
most threads these days), or insert threading tooling. I tend to use
the latter most of the time. Your SS is going to make this more
difficult, too.

After more reading here I've decided to drop the idea of getting the
grinder attachment for the lathe. I want to make some of my own tools,
so I'm studying up on bench grinders.

Mill round S.S. rods into square rods.

This, you could do in the milling adaptor on the lathe, with
either some form of index head for the lathe's milling adaptor (probably
difficult to find), or a collet block which will hold the workpiece.
And how long do these square parts need to be? A milling adaptor in a
lathe is not good for very long cuts.

I'm flexible on this at this point, but these rods will be about 1/2"
in diameter, and I'll only need to mill 1/4" of the rod's end into a
square.(A 1/4" thick disk with a square hole in the center will fit on
the end of the rod).

Tap 1/4" diameter holes into 7/16" diameter
S.S.rods.

Here, you can drill the tap holes in the lathe. You will then
probably start the tap in the lathe, but will then need to move the rod
to a vise, and use a hand tap holder to turn the tap.

All I could find at Micro-Mark is the following:
http://www.ares-server.com/Ares/Ares...oduct&ID=83146

But there is somethng called an E-Z hand tapper on eBay.(I've also seen
Enco tappers on eBay).

If the rods are too large to fit through the spindle, you will
need a fixed steady rest to support the rod out near the end where you
are drilling.

I'll keep an eye on eBay.

Drill 1/8" diameter holes through 1/4" S.S. rods.

Drill press -- unless you are drilling from one end to another.
And if so, how long is the rod? Drill bits tend to walk from a dead
on-center position, so you need to come up with another means to drill
it if the concentricity matters and the length is more than perhaps 1/2"
(with a 1/8" drill bit.)

The diameter that I'll have to drill through is 7/16"(which would
actually be the total of the rod inside the sleeve together).

Mill 3/4" wide, 1/8" deep grooves in S.S. plates.

Straight lines? Two flute end mills will work -- as long as the
grooves are not longer than the travel on your cross slide (for doing it
on a lathe).

I'll add those to my shopping list.

Radius corners to 1/2" in 1/16" thick S.S. plates.

For this, you will need some kind of tiny rotary table on the
milling attachment in the lathe. You would need one in a milling
machine as well, unless you have a CNC milling machine, which can simply
be told to cut the radius.

I'm going to have to search the internet for visual aids. Project sites
are difficult to come by, and Yahoop Groups is a pain.(BTW. I do know
that I'll also need some sort of indexing tool for making gears).

Mill out 1/4" diameter, 1/4" deep "cups" in S.S.

Round cups? For this, you will also need 1/4" ball end mills.
This is closer to drilling than to milling, as it is just a plunge
operation.

And this may be done in Delrin instead if it comes to that.

All of this is guesses based on what I remember of what you have
said in the past. I really think that you will need a capable machinist
to teach you how to do a lot of this, and to explain (and demonstrate)
why some of the things you want to do are beyond the capability of
anything that you can get up the stairs into your apartment.

I don't have a schooling option, so I'll have to wing it. But you've
given me a good idea of where to start.

Thanks a lot.

Darren Harris
Staten Island, New York.

According to :
Don,

Since we had gotten more and more off the original topic of "Mills and
Drills" I didn't want to irritate anyone further and so started this
thread to address what you told me.

And -- I'm starting to burn out. You are adding an extra hour
or more of typing to my evening newsreading time. (And, I'm going to be
quite busy for the next two days, so I might not be able to answer much
of anything during that time.

And -- it is still not at all clear that you *can* do SS --
depending on your choice of *which* of many Stainless Steels. Some of
those are very nasty to work.

I originally wanted to go with 316L stainless steel when I was
considering a larger lathe, but I'm now thinking more in terms of
Aluminum and 303 stainless steel. But the following are details of the
part of this project that *must* be made of 316L.S.S.

I still fail to see what gives the "must" for these.

1.00" of a 2-1/2" long, 7/16" diameter rod must be turned down to 1/4"
diameter.

O.K. As long as your lathe can handle 7/16" diameter though the
spindle, this should work reasonably. Much beyond 1" length at 1/4"
diameter would be a different matter.

The 7/16" diameter end will be threaded so it can be screwed
into a 316L stainless steel ball-knob.

Unless you can get the balls pre-threaded, this will call for
rather high quality taps, and you will need to replace them fairly
often, unless you are willing to use one until it breaks off in a
workpiece, thus junking the workpiece before switching to a new tap.

And -- you'll need a proper tapping fluid when tapping those
balls. I don't know what is the best fluid for that, so I'll let others
suggest for that. I don't work 316 SS.

The 1/4" diameter end will fit
into a 316L S.S. sleeve that will be 5/8" long, leaving a 3/8" area in
the assembly that is 1/4" diameter. To keep this sleeve on the main rod
I will need to drill a 1/8" hole all the way through the sleeve *and*
the rod inside so I can slide a tight fitting 1/8" Delrin rod to lock
them in place.

Why not something like Locktite to fixture it in place without
needing the drill and pin.

And why Delrin? If people are getting frantic and applying a
lot of force to this (it is sounding like the knob to a joystick), they
may well shear the Delrin at only 1/8" diameter. I would suggest a roll
pin instead, if you have room to drive it through when you need to
remove it.

I don't know what the milling attachment for the lathe will allow me to
do,

Not much, in SS. SS needs lots of rigidity, and a milling
attachment in a lathe normally lacks a lot of rigidity compared to a
true milling machine.

Even though it's a "baby-step" I'm considering the Micro-Mark mini-mill
to compliment the lathe.(Perhaps there will be compatible tooling
between the two).

Some -- mostly between the milling attachment for the lathe and
the real (but small) milling machine.

I'm just wondering if the milling attachment for the
lathe would make this unnecessary.(At least at this low level).

That depends on the size of your workpieces, among other things.

but some things below may require totally different tools.
Nevertheless, I still want to see how much I can get done on a lathe
before I really need a dedicated milling machine.

I will need to: Bore 1/4" wide, 1/4" deep circular grooves in S.S.

In flat SS, or in round stock? It sounds as though you are
planning to do this in flat workpieces (races for balls, I suspect, from
earlier postings you have made). And I presume that this means round
profiles to the groove as well as a circle form to the groove.

Actually, this would be a "trench" with a square profile.(But it's one
job I mentioned that I may not have to do).

O.K. Easier to do on the milling machine with a rotary table to
rotate the workpiece around the center of the circle formed by the trough.

To do this on a lathe, you will need a form tool corresponding
to the shape you need to produce, and that is going to be nasty to use.
A quick calculation says that a 1/4" wide groove will need the tool
cutting on a 0.3927" wide surface. I would not really like to do this
on my 12" lathe, let alone your little 7" (IIRC) lathe. Most of my
tools cut on (at most) a 1/8" (0.125") long edge before the power of my
1-1/2 HP motor gets to struggling.

Then I definitely wouldn't try it on the Microlux lathe. :-)

If it is a square bottomed trough, you could turn it, using a
tool ground as a trepaning tool (and with the workpiece held in a 4-jaw
chuck, if it is small enough to be rotated around the center of the
trough circle above the bed without hitting the bed.

You cut a fairly narrow groove, them move out and plunge again
until you get the full width. Then you move the tool sideways to smooth
out the bottom of the groove.

And you've been talking (in another thread) about rigidity not
mattering as much on a small lathe. When you do something like this in
Stainless Steel, you're going to need every bit of rigidity you can
find. If you don't have the rigidity to take a reasonable cut, and the
power to keep it going, the SS is going to work harden and then fight
you all the way.

Yes. But just to reiterate, stainless steel is the extreme. And thanks
to your advice I'm using it as a yardstick to determine what is and
isn't plausible with the MM lathe.

No -- SS is *an* extreme. There are other things which are more
difficult to machine -- though you have not yet mentioned wanting to
machine them. These include hardened tool steel. (Better done with a
toolpost grinder than a turning tool.)

On a *mill*, you would want a 1/4" ball-end mill, and a rotary
table to turn the workpiece under the mill.

And -- your talk of 1/4" deep as well as 1/4" wide says that the
top of the balls will not show above the surface, so it will offer no
bearing operation -- even if by some miracle you get a smooth enough
finish to have the groove act as a reasonable bearing race. Your groove
should not be that deep.

If I did end up doing this I would place a 1/16" Delrin "floor" inside
the groove.(But as it stands now, I'm going with he Delrin "cup" idea
so the bearings will touch only Delrin and not metal).

O.K. How much force per ball? How long will it set in one
place with the full load? That might cause the balls to indent the
Delrin, making bumps as it moves later.

Turn down 7/16" diameter S.S. rods to 1/4".

How long? If the length is more than four times the diameter
(final diameter, not starting diameter) and you are turning in a chuck,
you will need a "traveling steady rest" (also called a "follower rest").
If it is more than double that, you will need the traveling steady even
for workpieces turned between centers. (And you will need a ball
bearing "live" center in the tailstock.)

MM sells a live center set for $92.65(#83185), and a live ball bearing
center for $12.95(#82509).

The set probably includes several special points for handling
strange shaped workpieces, and you probably don't need that at present.
Wait until you get a project needing that before ordering.

I'm also looking at that steady rest for
$31.45(#82503) and the follower rest (#82504) on the Micro-Mark
mini-lathe page, but it doesn't say "traveling".

"Traveling rest" is a UK way of saying "follower rest" --
different terms, same item.

And again -- which alloy of SS?

316L

Which I have not used.

Thread S.S. rods to fit rod-ends, knobs, ect.

This also calls for a lot of rigidity. You will need either HSS
toolbits ground to the proper angles for the threading (60 degrees for
most threads these days), or insert threading tooling. I tend to use
the latter most of the time. Your SS is going to make this more
difficult, too.

After more reading here I've decided to drop the idea of getting the
grinder attachment for the lathe. I want to make some of my own tools,
so I'm studying up on bench grinders.

Far better. A grinder on the lathe leaves abrasive compounds on
the ways, and leads to rapid bed wear. You have to jump through hoops
to protect the bed and other parts of the lathe.

Mill round S.S. rods into square rods.

This, you could do in the milling adaptor on the lathe, with
either some form of index head for the lathe's milling adaptor (probably
difficult to find), or a collet block which will hold the workpiece.
And how long do these square parts need to be? A milling adaptor in a
lathe is not good for very long cuts.

I'm flexible on this at this point, but these rods will be about 1/2"
in diameter, and I'll only need to mill 1/4" of the rod's end into a
square.

O.K. That should be doable on the milling attachment. The main
trick (solved by the collet block) is having a way to turn the workpiece
precisely 90 degrees for the next cut.

(A 1/4" thick disk with a square hole in the center will fit on
the end of the rod).

O.K.

Tap 1/4" diameter holes into 7/16" diameter
S.S.rods.

Here, you can drill the tap holes in the lathe. You will then
probably start the tap in the lathe, but will then need to move the rod
to a vise, and use a hand tap holder to turn the tap.

All I could find at Micro-Mark is the following:
http://www.ares-server.com/Ares/Ares...oduct&ID=83146

But there is somethng called an E-Z hand tapper on eBay.(I've also seen
Enco tappers on eBay).

Neither of these are what I was talking about. Those are for
tapping holes properly vertical in plates of material. And it might be
difficult to hold the workpiece properly vertical, even with the vise
shown as an accessory.

What I am talking about are tapping *wrenches*, which form a
T-bar around the end of the tap, and are turned by hand. The knob on
the top of that tool you've ponted to will be too small for driving a
1/4" tap into stainless steel.

Micro-Mark is *not* the be-all and end-all of machining
supplies. Call up MSC, and register with them. They will send you a
4000+ page catalog, which can show you more than you ever imagined in
the way of tools. And -- you can take it with you to the john, to learn
more about what is available, which you can't do with a web page,
unless you use a laptop and a wireless net connection. :-)

But be careful to not loose circulation in your legs with that
big catalog on your lap.

If the rods are too large to fit through the spindle, you will
need a fixed steady rest to support the rod out near the end where you
are drilling.

I'll keep an eye on eBay.

The steady rests should be ordered *with* the lathe, as they are
specific to the lathe's design. Many other things are more adaptable.

Drill 1/8" diameter holes through 1/4" S.S. rods.

Drill press -- unless you are drilling from one end to another.
And if so, how long is the rod? Drill bits tend to walk from a dead
on-center position, so you need to come up with another means to drill
it if the concentricity matters and the length is more than perhaps 1/2"
(with a 1/8" drill bit.)

The diameter that I'll have to drill through is 7/16"(which would
actually be the total of the rod inside the sleeve together).

O.K. A small benchtop drill press (perhaps $50.00 or less from
eBay to get a junky one, but one which you can carry upstairs in one
hand. It may be sloppy, however.

Mill 3/4" wide, 1/8" deep grooves in S.S. plates.

Straight lines? Two flute end mills will work -- as long as the
grooves are not longer than the travel on your cross slide (for doing it
on a lathe).

I'll add those to my shopping list.

The two-flute ones are the best for milling slots. In England,
they are called "slot drills" for that reason.

Radius corners to 1/2" in 1/16" thick S.S. plates.

For this, you will need some kind of tiny rotary table on the
milling attachment in the lathe. You would need one in a milling
machine as well, unless you have a CNC milling machine, which can simply
be told to cut the radius.

And -- of course, this depends on how large the workpiece is,
since it has to rotate above the bed of the lathe without hitting it.

I'm going to have to search the internet for visual aids. Project sites
are difficult to come by, and Yahoop Groups is a pain.(BTW. I do know
that I'll also need some sort of indexing tool for making gears).

Mill out 1/4" diameter, 1/4" deep "cups" in S.S.

Round cups? For this, you will also need 1/4" ball end mills.
This is closer to drilling than to milling, as it is just a plunge
operation.

And this may be done in Delrin instead if it comes to that.

All of this is guesses based on what I remember of what you have
said in the past. I really think that you will need a capable machinist
to teach you how to do a lot of this, and to explain (and demonstrate)
why some of the things you want to do are beyond the capability of
anything that you can get up the stairs into your apartment.

I don't have a schooling option, so I'll have to wing it. But you've
given me a good idea of where to start.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

And -- I'm starting to burn out. You are adding an extra hour
or more of typing to my evening newsreading time. (And, I'm going to be
quite busy for the next two days, so I might not be able to answer much
of anything during that time.

No problem. I'm just trying to address all the loose ends, so my goals
are clear. No need to spend so much of your time typing. You've helped
me out a lot already. Not just with your direct responses(which have
been pretty fast), but also with your archived posts I've spent hours
reading.

I originally wanted to go with 316L stainless steel when I was
considering a larger lathe, but I'm now thinking more in terms of
Aluminum and 303 stainless steel. But the following are details of the
part of this project that *must* be made of 316L.S.S.

I still fail to see what gives the "must" for these.

A gamer's hands can get pretty sweaty in the heat of battle.(But I'll
have to settle for 303, since no one makes 316* 1-3/8" diameter ball
knobs).

O.K. As long as your lathe can handle 7/16" diameter though the
spindle, this should work reasonably.

The site page for my lathe makes reference to a 5/8" dia. thru-hole, so
that may be it.

Much beyond 1" length at 1/4"
diameter would be a different matter.

Well, the rod will still be 2-1/2"(to 2-3/4") long. only 1" of it will
be turned down to 1/4" from 7/16".

The 7/16" diameter end will be threaded so it can be screwed
into a 316L stainless steel ball-knob.

Unless you can get the balls pre-threaded, this will call for
rather high quality taps, and you will need to replace them fairly
often, unless you are willing to use one until it breaks off in a
workpiece, thus junking the workpiece before switching to a new tap.

And -- you'll need a proper tapping fluid when tapping those
balls. I don't know what is the best fluid for that, so I'll let others
suggest for that. I don't work 316 SS.

The ball-knobs from McMaster Carr are pre-threaded. I just have to
decide on which of the following eight threads to get.(Though I suspect
that it'll make no difference).

1) 1/4" - 20
2) 5/16" - 18
3) 5/16" - 24
4) 3/8" - 16
5) 3/8" - 24
6) 7/16" - 20
7) 1/2" - 13
8) 1/2" - 20

The 1/4" diameter end will fit
into a 316L S.S. sleeve that will be 5/8" long, leaving a 3/8" area in
the assembly that is 1/4" diameter. To keep this sleeve on the main rod
I will need to drill a 1/8" hole all the way through the sleeve *and*
the rod inside so I can slide a tight fitting 1/8" Delrin rod to lock
them in place.

Why not something like Locktite to fixture it in place without
needing the drill and pin.

Because I want the option of taking it apart in the future for part
replacement. I was however thinking of using Locktite where the rod
screws into the ball knob. That is the fit that needs to be permanent.

And why Delrin? If people are getting frantic and applying a
lot of force to this (it is sounding like the knob to a joystick), they
may well shear the Delrin at only 1/8" diameter. I would suggest a roll
pin instead, if you have room to drive it through when you need to
remove it.


There will be no room for protrusions, so the length of the 1/8"
diameter Delrin rod will equal the diameter it is placed in(which is
7/16"). I figure that Delrin(or nylon) in the proper size would make
for a tighter fit than a metal pin. And I can just punch it out when I
need to.

I'm just wondering if the milling attachment for the
lathe would make this unnecessary.(At least at this low level).

That depends on the size of your workpieces, among other things.

Of course the work envelope(whatever that will be) will be the big
difference, but outside of that I'll need to determine how big a
difference there would be in other ways between this lathe(with
attachment) and a mini-mill.

If it is a square bottomed trough, you could turn it, using a
tool ground as a trepaning tool (and with the workpiece held in a 4-jaw
chuck, if it is small enough to be rotated around the center of the
trough circle above the bed without hitting the bed.

The largest workpieces will be A) 4-1/2" square(6" diagonal), 3/16"
thick, and B) 4" square, 1/4" thick. I'm actually *considering* using
5052 Aluminum.(6061 would be my second choice). The reason is because
I'm concerned about the possibility that the stiffness of S.S. steel
may cause the assembly to lock, and aluminum's flex may prevent that.
I'm probably worried about nothing, because this part is basically a
flat Delrin surface that will be sliding(a half inch in any direction)
between upper and lower bearings situated inside Delrin cups.

Yes. But just to reiterate, stainless steel is the extreme. And thanks
to your advice I'm using it as a yardstick to determine what is and
isn't plausible with the MM lathe.

No -- SS is *an* extreme. There are other things which are more
difficult to machine -- though you have not yet mentioned wanting to
machine them. These include hardened tool steel. (Better done with a
toolpost grinder than a turning tool.)

Actually, what I meant was that S.S. is the most estreme material *I*
will be working with. :-)

If I did end up doing this I would place a 1/16" Delrin "floor" inside
the groove.(But as it stands now, I'm going with he Delrin "cup" idea
so the bearings will touch only Delrin and not metal).

O.K. How much force per ball? How long will it set in one
place with the full load? That might cause the balls to indent the
Delrin, making bumps as it moves later.

That's the reason for the *replaceable* Delrin ring(floor) idea. :-)
But the downward force will for the most part be insignificant, since
the push of the "race face" will tend to be horizontal. It's still
smart to assume the occasional downward push(though there is no point
to doing that), but again, these are prototypes and I will be getting
feedback so I can determine where the weak links are.

MM sells a live center set for $92.65(#83185), and a live ball bearing
center for $12.95(#82509).

The set probably includes several special points for handling
strange shaped workpieces, and you probably don't need that at present.
Wait until you get a project needing that before ordering.

My intentions exactly.

Mill round S.S. rods into square rods.

This, you could do in the milling adaptor on the lathe, with
either some form of index head for the lathe's milling adaptor (probably
difficult to find), or a collet block which will hold the workpiece.
And how long do these square parts need to be? A milling adaptor in a
lathe is not good for very long cuts.

I'm flexible on this at this point, but these rods will be about 1/2"
in diameter, and I'll only need to mill 1/4" of the rod's end into a
square.

O.K. That should be doable on the milling attachment. The main
trick (solved by the collet block) is having a way to turn the workpiece
precisely 90 degrees for the next cut.

Ok. "Collet block". I'm on it.

Tap 1/4" diameter holes into 7/16" diameter
S.S.rods.

Here, you can drill the tap holes in the lathe. You will then
probably start the tap in the lathe, but will then need to move the rod
to a vise, and use a hand tap holder to turn the tap.

All I could find at Micro-Mark is the following:
http://www.ares-server.com/Ares/Ares...oduct&ID=83146

But there is somethng called an E-Z hand tapper on eBay.(I've also seen
Enco tappers on eBay).

Neither of these are what I was talking about. Those are for
tapping holes properly vertical in plates of material. And it might be
difficult to hold the workpiece properly vertical, even with the vise
shown as an accessory.

What I am talking about are tapping *wrenches*, which form a
T-bar around the end of the tap, and are turned by hand. The knob on
the top of that tool you've ponted to will be too small for driving a
1/4" tap into stainless steel.

Yes, I know. I was just trying to indicate that that was all M.M.
had(since I already had M.M. open in a browser window as I was typing).
But if the "T-bar" is what you turn, then I'm confused, because the E-Z
tappers and Encos I see have that.

Micro-Mark is *not* the be-all and end-all of machining
supplies. Call up MSC, and register with them. They will send you a
4000+ page catalog, which can show you more than you ever imagined in
the way of tools. And -- you can take it with you to the john, to learn
more about what is available, which you can't do with a web page,
unless you use a laptop and a wireless net connection. :-)

But be careful to not loose circulation in your legs with that
big catalog on your lap.

:-) I tried getting a catalog from them a couple of months ago with no
luck. Even though they advertsie the catalog, there are no options for
getting it.(My Grizzly catalog just arrived though).

The steady rests should be ordered *with* the lathe, as they are
specific to the lathe's design. Many other things are more adaptable.

Ok, I guess I have to get the two I mentioned on the M.M. lathe page.

The diameter that I'll have to drill through is 7/16"(which would
actually be the total of the rod inside the sleeve together).

O.K. A small benchtop drill press (perhaps $50.00 or less from
eBay to get a junky one, but one which you can carry upstairs in one
hand. It may be sloppy, however.

Obviously "small" and "accurate" don't go together on any of these
machines.

Radius corners to 1/2" in 1/16" thick S.S. plates.

For this, you will need some kind of tiny rotary table on the
milling attachment in the lathe. You would need one in a milling
machine as well, unless you have a CNC milling machine, which can simply
be told to cut the radius.

And -- of course, this depends on how large the workpiece is,
since it has to rotate above the bed of the lathe without hitting it.

My wording probably wasn't clear enough. Basically, I'll need to turn a
4-1/2" square(1/16" thick) plate into a 3" disk that has four 1/2" wide
arms that are rounded at the ends.

I'll still need to get a rotary table, so I'll be searching the
internet for a visual on anything relating to a rotary table on a lathe
that has a milling attachment.

Thanks a lot.

Darren Harris
Staten Island, New York.

According to :
And -- I'm starting to burn out. You are adding an extra hour
or more of typing to my evening newsreading time. (And, I'm going to be
quite busy for the next two days, so I might not be able to answer much
of anything during that time.

No problem. I'm just trying to address all the loose ends, so my goals
are clear. No need to spend so much of your time typing. You've helped
me out a lot already. Not just with your direct responses(which have
been pretty fast), but also with your archived posts I've spent hours
reading.

I'm glad that you're digging through the archives, too.

I originally wanted to go with 316L stainless steel when I was
considering a larger lathe, but I'm now thinking more in terms of
Aluminum and 303 stainless steel. But the following are details of the
part of this project that *must* be made of 316L.S.S.

I still fail to see what gives the "must" for these.

A gamer's hands can get pretty sweaty in the heat of battle.(But I'll
have to settle for 303, since no one makes 316* 1-3/8" diameter ball
knobs).

What is wrong with the black Bakelite knobs which are also
available with cast-in brass inserts with female threads for screwing
onto your shaft? They are a bit lighter than the stainless steel, and
certainly a lot less expensive.

O.K. As long as your lathe can handle 7/16" diameter though the
spindle, this should work reasonably.

The site page for my lathe makes reference to a 5/8" dia. thru-hole, so
that may be it.

Oops! That means that you will need to learn to use the fixed
steady rest to support the outboard end of the workpiece.

Much beyond 1" length at 1/4"
diameter would be a different matter.

Well, the rod will still be 2-1/2"(to 2-3/4") long. only 1" of it will
be turned down to 1/4" from 7/16".

But you can't grip it close enough in the lathe chuck to
minimize the part which extends, so you will have to use the fixed
steady to support it just back of the 1" to be turned down.

The 7/16" diameter end will be threaded so it can be screwed
into a 316L stainless steel ball-knob.

Unless you can get the balls pre-threaded, this will call for
rather high quality taps, and you will need to replace them fairly
often, unless you are willing to use one until it breaks off in a
workpiece, thus junking the workpiece before switching to a new tap.

And -- you'll need a proper tapping fluid when tapping those
balls. I don't know what is the best fluid for that, so I'll let others
suggest for that. I don't work 316 SS.

The ball-knobs from McMaster Carr are pre-threaded. I just have to
decide on which of the following eight threads to get.(Though I suspect
that it'll make no difference).

1) 1/4" - 20
2) 5/16" - 18
3) 5/16" - 24
4) 3/8" - 16
5) 3/8" - 24
6) 7/16" - 20
7) 1/2" - 13
8) 1/2" - 20

I would suggest avoiding the 1/4-20, if the balls are going to
be slammed around by an engrossed gamer. Any of the others should be
fine, and the choice probably should be based on the thread which is
easiest to cut in *your* lathe.

The 1/4" diameter end will fit
into a 316L S.S. sleeve that will be 5/8" long, leaving a 3/8" area in
the assembly that is 1/4" diameter. To keep this sleeve on the main rod
I will need to drill a 1/8" hole all the way through the sleeve *and*
the rod inside so I can slide a tight fitting 1/8" Delrin rod to lock
them in place.

Why not something like Locktite to fixture it in place without
needing the drill and pin.

Because I want the option of taking it apart in the future for part
replacement. I was however thinking of using Locktite where the rod
screws into the ball knob. That is the fit that needs to be permanent.

O.K. Loctite can be unscrewed -- if you heat it up with a torch
first.

And why Delrin? If people are getting frantic and applying a
lot of force to this (it is sounding like the knob to a joystick), they
may well shear the Delrin at only 1/8" diameter. I would suggest a roll
pin instead, if you have room to drive it through when you need to
remove it.


There will be no room for protrusions, so the length of the 1/8"
diameter Delrin rod will equal the diameter it is placed in(which is
7/16"). I figure that Delrin(or nylon) in the proper size would make
for a tighter fit than a metal pin. And I can just punch it out when I
need to.

You are obviously not familiar with a roll pin. Picture a
length of flat spring steel stock which has been rolled into a two-turn
roll. The ends are tapered a bit to make them easy to start, and they
are driven into the mating holes, with the spring expanding to grip both
the parts. They can be driven out as long as the hole goes all the way
through. They are available for relatively little money for large
quantities. With blind holes, people have managed to use a tap to
thread the ID and give a grip with a screw to pull them out.

I'm just wondering if the milling attachment for the
lathe would make this unnecessary.(At least at this low level).

That depends on the size of your workpieces, among other things.

Of course the work envelope(whatever that will be) will be the big
difference, but outside of that I'll need to determine how big a
difference there would be in other ways between this lathe(with
attachment) and a mini-mill.

Of course.

If it is a square bottomed trough, you could turn it, using a
tool ground as a trepaning tool (and with the workpiece held in a 4-jaw
chuck, if it is small enough to be rotated around the center of the
trough circle above the bed without hitting the bed.

The largest workpieces will be A) 4-1/2" square(6" diagonal), 3/16"
thick, and B) 4" square, 1/4" thick.

O.K. It could require somewhat over that 6" diagonal, if the
groove has to be around a point other than the center, because it *must*
rotate around the center of the groove to be.

I'm actually *considering* using
5052 Aluminum.(6061 would be my second choice).

O.K. I haven't worked the 5052, and it is too late to look up
its characteristics, but as long as it isn't a dead soft aluminum (pure
aluminum) it will probably do.

It should be a *lot* easier to machine than the Stainless steel.

The reason is because
I'm concerned about the possibility that the stiffness of S.S. steel
may cause the assembly to lock, and aluminum's flex may prevent that.

Given the size of the workpiece, I don't expect too much flex
from 1/4" thick aluminum, let alone SS. :-)

I'm probably worried about nothing, because this part is basically a
flat Delrin surface that will be sliding(a half inch in any direction)
between upper and lower bearings situated inside Delrin cups.

O.K.

[ ... ]

If I did end up doing this I would place a 1/16" Delrin "floor" inside
the groove.(But as it stands now, I'm going with he Delrin "cup" idea
so the bearings will touch only Delrin and not metal).

O.K. How much force per ball? How long will it set in one
place with the full load? That might cause the balls to indent the
Delrin, making bumps as it moves later.

That's the reason for the *replaceable* Delrin ring(floor) idea. :-)
But the downward force will for the most part be insignificant, since
the push of the "race face" will tend to be horizontal. It's still
smart to assume the occasional downward push(though there is no point
to doing that), but again, these are prototypes and I will be getting
feedback so I can determine where the weak links are.

O.K. You can replace it with other materials if it shows as
problematic.

[ ... ]

I'm flexible on this at this point, but these rods will be about 1/2"
in diameter, and I'll only need to mill 1/4" of the rod's end into a
square.

O.K. That should be doable on the milling attachment. The main
trick (solved by the collet block) is having a way to turn the workpiece
precisely 90 degrees for the next cut.

Ok. "Collet block". I'm on it.

O.K.

Tap 1/4" diameter holes into 7/16" diameter
S.S.rods.

Here, you can drill the tap holes in the lathe. You will then
probably start the tap in the lathe, but will then need to move the rod
to a vise, and use a hand tap holder to turn the tap.

All I could find at Micro-Mark is the following:

http://www.ares-server.com/Ares/Ares...oduct&ID=83146

But there is somethng called an E-Z hand tapper on eBay.(I've also seen
Enco tappers on eBay).

Neither of these are what I was talking about. Those are for
tapping holes properly vertical in plates of material. And it might be
difficult to hold the workpiece properly vertical, even with the vise
shown as an accessory.

What I am talking about are tapping *wrenches*, which form a
T-bar around the end of the tap, and are turned by hand. The knob on
the top of that tool you've ponted to will be too small for driving a
1/4" tap into stainless steel.

Yes, I know. I was just trying to indicate that that was all M.M.
had(since I already had M.M. open in a browser window as I was typing).
But if the "T-bar" is what you turn, then I'm confused, because the E-Z
tappers and Encos I see have that.

What you are looking at are designed to hold flat workpieces and
feed the tap in truly square to the surface. Your rod, with a hole in
the end, would be difficult to mount truly vertically so the tap is
guided in square.

Let me try an ASCII drawing of the kind of tap wrench that I'm
talking about. You'll need to set your screen to a fixed pitch font
like Courier to keep the drawing from being distorted.
__________
___________________/ ______ \_____________________
(___________________ |____| _____________________)
\__________/

The diamond shape in the center adjusts to wider or narrower by turning
one of the handles, which screws into the center part. This closes on
the square on the end of the tap's shank, gripping it and allowing the
wrench to turn the tap.

It takes a steady hand to work with small taps with one like
this. I've used them down to 0-80 taps with small versions of the
wrench and with reasonable care. But your taps are large enough so
you should have no real problems.

Micro-Mark is *not* the be-all and end-all of machining
supplies. Call up MSC, and register with them. They will send you a
4000+ page catalog, which can show you more than you ever imagined in
the way of tools. And -- you can take it with you to the john, to learn
more about what is available, which you can't do with a web page,
unless you use a laptop and a wireless net connection. :-)

But be careful to not loose circulation in your legs with that
big catalog on your lap.

:-) I tried getting a catalog from them a couple of months ago with no
luck. Even though they advertsie the catalog, there are no options for
getting it.(My Grizzly catalog just arrived though).

Did you phone them?

Did you register with them? (They give you a customer number to
use in subsequent orders.)

Is it possible that they delivered one and it was stolen? They
normally send the catalogs via UPS, same as the parts which they
sell. (Though the last catalog came via USPS instead, IIRC.)

Or -- do you have a lazy mailman? One who won't deliver
anything which does not fit in your mailbox?

Or -- it might just be that they're out of that catalog, and the
new one is just about to be printed and shipped.

The steady rests should be ordered *with* the lathe, as they are
specific to the lathe's design. Many other things are more adaptable.

Ok, I guess I have to get the two I mentioned on the M.M. lathe page.

Yep

The diameter that I'll have to drill through is 7/16"(which would
actually be the total of the rod inside the sleeve together).

O.K. A small benchtop drill press (perhaps $50.00 or less from
eBay to get a junky one, but one which you can carry upstairs in one
hand. It may be sloppy, however.

Obviously "small" and "accurate" don't go together on any of these
machines.

Nope -- though they do on ones like my Cameron Micro Precision
sensitive drill press. It is a maximum chuck capacity of 1/8" with the
Albrecht chuck, though a small Jacobs 3/16" chuck can be fitted to the
drill press. It is precise enough so it handles #80 drill bits (Hard to
see, even in the drill index) with no problems.

Radius corners to 1/2" in 1/16" thick S.S. plates.

For this, you will need some kind of tiny rotary table on the
milling attachment in the lathe. You would need one in a milling
machine as well, unless you have a CNC milling machine, which can simply
be told to cut the radius.

And -- of course, this depends on how large the workpiece is,
since it has to rotate above the bed of the lathe without hitting it.

My wording probably wasn't clear enough. Basically, I'll need to turn a
4-1/2" square(1/16" thick) plate into a 3" disk that has four 1/2" wide
arms that are rounded at the ends.

Hmm ... Do they need to be a full 180 degrees of rounding, or
just a gentle curve. The latter can be turned in the lathe. The former
will take either a rotary table, or a larger mill with a corner rounding
end mill.

I'll still need to get a rotary table, so I'll be searching the
internet for a visual on anything relating to a rotary table on a lathe
that has a milling attachment.

I've never seen such a combination. It is something which you
will have to make up out of parts which you can find and combine
together. A lot of machining is making special combinations of existing
tools. So -- you are highly unlikely to find such a visual. This is
one of those "figure it out for yourself" tasks.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

A gamer's hands can get pretty sweaty in the heat of battle.(But I'll
have to settle for 303, since no one makes 316* 1-3/8" diameter ball
knobs).

What is wrong with the black Bakelite knobs which are also
available with cast-in brass inserts with female threads for screwing
onto your shaft? They are a bit lighter than the stainless steel, and
certainly a lot less expensive.

Yes, but they wouldn't give it that solid, heavy, durable, quality look
and feel that a stainless steel ball-top would. :-)

O.K. Loctite can be unscrewed -- if you heat it up with a torch
first.

That would be a pain. And since this sleeve will be wedged against a
(3" diameter)Delrin plate I don't think that'll work.

You are obviously not familiar with a roll pin. Picture a
length of flat spring steel stock which has been rolled into a two-turn
roll. The ends are tapered a bit to make them easy to start, and they
are driven into the mating holes, with the spring expanding to grip both
the parts. They can be driven out as long as the hole goes all the way
through. They are available for relatively little money for large
quantities. With blind holes, people have managed to use a tap to
thread the ID and give a grip with a screw to pull them out.

It would seem to be more reliable(though not easier or cheaper) than
using Delrin rods. So I'll look that up. (Tapping is going to be a
subject unto itself that I'll have to study).

The largest workpieces will be A) 4-1/2" square(6" diagonal), 3/16"
thick, and B) 4" square, 1/4" thick.

O.K. It could require somewhat over that 6" diagonal, if the
groove has to be around a point other than the center, because it *must*
rotate around the center of the groove to be.

The groove(which would have a 3" O.D.) would actually have to be made
in the 4" square piece.

I'm actually *considering* using
5052 Aluminum.(6061 would be my second choice).

Given the size of the workpiece, I don't expect too much flex
from 1/4" thick aluminum, let alone SS. :-)

Well, if I go with Aluminum, most of it would be turned/milled down to
1/16" thick. Only a ring(with an O.D. of 2-5/8") would be left. (And a
3/8" Delrin ring(with "cups" drilled into it for the bearings) would
fit around this.

In fact the above may just be the best idea.

What you are looking at are designed to hold flat workpieces and
feed the tap in truly square to the surface. Your rod, with a hole in
the end, would be difficult to mount truly vertically so the tap is
guided in square.

Let me try an ASCII drawing of the kind of tap wrench that I'm
talking about. You'll need to set your screen to a fixed pitch font
like Courier to keep the drawing from being distorted.
__________
___________________/ ________ \_____________________
(___________________ |__ __| _____________________)
\__________/

I clicked "Fixed Font" on this Google page and it was no better than
proportionate. But when I clicked print to bring up the printer
friendly page your ASCII drawing came out perfect.

I was looking at those tap wrenches on the Grizzly catalog, so I'll
have to investigate further what I'll need to drill that 1/8" diameter
hole through rod and sleeve.

BTW. I suspect that the 11/16" long sleeve(tube) would be easier to buy
than to attempt to drill a rod that length end to end.

But be careful to not loose circulation in your legs with that
big catalog on your lap.

:-) I tried getting a catalog from them a couple of months ago with no
luck. Even though they advertsie the catalog, there are no options for
getting it.(My Grizzly catalog just arrived though).

Did you phone them?

Did you register with them? (They give you a customer number to
use in subsequent orders.)

Is it possible that they delivered one and it was stolen? They
normally send the catalogs via UPS, same as the parts which they
sell. (Though the last catalog came via USPS instead, IIRC.)

Or -- do you have a lazy mailman? One who won't deliver
anything which does not fit in your mailbox?

Or -- it might just be that they're out of that catalog, and the
new one is just about to be printed and shipped.

I'll try again.

The diameter that I'll have to drill through is 7/16"(which would
actually be the total of the rod inside the sleeve together).

O.K. A small benchtop drill press (perhaps $50.00 or less from
eBay to get a junky one, but one which you can carry upstairs in one
hand. It may be sloppy, however.

Obviously "small" and "accurate" don't go together on any of these
machines.

Nope -- though they do on ones like my Cameron Micro Precision
sensitive drill press. It is a maximum chuck capacity of 1/8" with the
Albrecht chuck, though a small Jacobs 3/16" chuck can be fitted to the
drill press. It is precise enough so it handles #80 drill bits (Hard to
see, even in the drill index) with no problems.

I believe I'v seen simular drill presses go for $400+ on eBay. Anyway,
I can only hope that one of the $50 bench tops will allow enough
accuracy for my needs. I suppose I'll need it to be pretty accurate if
I go with the roll pin.

My wording probably wasn't clear enough. Basically, I'll need to turn a
4-1/2" square(1/16" thick) plate into a 3" disk that has four 1/2" wide
arms that are rounded at the ends.

Hmm ... Do they need to be a full 180 degrees of rounding, or
just a gentle curve. The latter can be turned in the lathe. The former
will take either a rotary table, or a larger mill with a corner rounding
end mill.

Technically, I can leave this piece pointed at all four ends, but I
just wanted to clean things up. I'm flexible, so I'll see what can be
done.

I'll still need to get a rotary table, so I'll be searching the
internet for a visual on anything relating to a rotary table on a lathe
that has a milling attachment.

I've never seen such a combination. It is something which you
will have to make up out of parts which you can find and combine
together. A lot of machining is making special combinations of existing
tools. So -- you are highly unlikely to find such a visual. This is
one of those "figure it out for yourself" tasks.

Yes. That is why I joned a Yahoo Group "mlathemods - Mini Lathe
Modifications". Perhaps there will be some ideas there.

BTW. I have a line on an Enco lathe that is supposed to have a lot of
tooling for $550. The seller says he thinks is a 9" by 16", but I don't
know if that even exists. I've only been able to find references to a 9
X 20(#308-0338).

Thanks.

Darren Harris
Staten Island, New York.

According to :

What is wrong with the black Bakelite knobs which are also
available with cast-in brass inserts with female threads for screwing
onto your shaft? They are a bit lighter than the stainless steel, and
certainly a lot less expensive.

Yes, but they wouldn't give it that solid, heavy, durable, quality look
and feel that a stainless steel ball-top would. :-)

The Bakelite ball is pretty solid, so it may work well.

O.K. Loctite can be unscrewed -- if you heat it up with a torch
first.

That would be a pain. And since this sleeve will be wedged against a
(3" diameter)Delrin plate I don't think that'll work.

O.K.

You are obviously not familiar with a roll pin. Picture a
length of flat spring steel stock which has been rolled into a two-turn
roll. The ends are tapered a bit to make them easy to start, and they
are driven into the mating holes, with the spring expanding to grip both
the parts. They can be driven out as long as the hole goes all the way
through. They are available for relatively little money for large
quantities. With blind holes, people have managed to use a tap to
thread the ID and give a grip with a screw to pull them out.

It would seem to be more reliable(though not easier or cheaper) than
using Delrin rods.

It may well be cheaper than using Delrin rods. After all, these
are mass produced to standard diameters and lengths. Delrin tends to be
rather expensive (though something like 1/8" diameter rods would not be
that expensive, and you would simply have to turn them to the desired
final diameter and cut them to length.

So I'll look that up. (Tapping is going to be a
subject unto itself that I'll have to study).

Indeed so.

The largest workpieces will be A) 4-1/2" square(6" diagonal), 3/16"
thick, and B) 4" square, 1/4" thick.

O.K. It could require somewhat over that 6" diagonal, if the
groove has to be around a point other than the center, because it *must*
rotate around the center of the groove to be.

The groove(which would have a 3" O.D.) would actually have to be made
in the 4" square piece.

But -- the groove could be off towards one corner, so it is just
barely grazing two sides, and that would result in the other sides
extending 1" beyond what would be the case with a centered plate. And
that would be 1.414" beyond at the corner. So -- what would have been a
5.65" diameter if centered would be closer to an 8.48" effective
diameter. This is why I specified the center point of the groove being
important.

Granted, I suspect that the groove *will* be centered, but I
want to point out the problems you can have if you make that assumption
blindly.

I'm actually *considering* using
5052 Aluminum.(6061 would be my second choice).

Given the size of the workpiece, I don't expect too much flex
from 1/4" thick aluminum, let alone SS. :-)

Well, if I go with Aluminum, most of it would be turned/milled down to
1/16" thick. Only a ring(with an O.D. of 2-5/8") would be left. (And a
3/8" Delrin ring(with "cups" drilled into it for the bearings) would
fit around this.

In fact the above may just be the best idea.

O.K.

What you are looking at are designed to hold flat workpieces and
feed the tap in truly square to the surface. Your rod, with a hole in
the end, would be difficult to mount truly vertically so the tap is
guided in square.

Let me try an ASCII drawing of the kind of tap wrench that I'm
talking about. You'll need to set your screen to a fixed pitch font
like Courier to keep the drawing from being distorted.
___________
___________________/ ________ \_____________________
(___________________ |__ __| _____________________)
\___________/

I clicked "Fixed Font" on this Google page and it was no better than
proportionate. But when I clicked print to bring up the printer
friendly page your ASCII drawing came out perfect.

Ouch! -- You are using *Google* for this? I'm glad that you
found a way to get it to display properly. And I had to re-adjust the
tap wrench to correct for whatever Google did to it when you quoted it
in your followup.

I was looking at those tap wrenches on the Grizzly catalog, so I'll
have to investigate further what I'll need to drill that 1/8" diameter
hole through rod and sleeve.

For that -- I would suggest that you look for a bench block
(Starrett makes two sizes, and you would want the smaller of the two.)
Check out eBay auctions 7587959068 and 7587168821 to see what they look
like. The first auction has only eight minutes left as I type, so you
are unlikely to get it.

But -- the V-groove supports the shaft (and the sleeve), and
there is a small hole at the bottom of the V-groove to clear the drill
(or to clear a pin when it is being driven out).

The second one is being sold from the UK, and who knows who
really made it. It looks nice, at least.

The last one is also a Starrett, but is the larger one, and I
think that it would be less satisfactory.

BTW. I suspect that the 11/16" long sleeve(tube) would be easier to buy
than to attempt to drill a rod that length end to end.

Perhaps -- if you can find the right size. Or, you might be
able to buy it as a long sleeving, and part it off to length.

[ ... MSC catalog ... ]

But be careful to not loose circulation in your legs with that
big catalog on your lap.

:-) I tried getting a catalog from them a couple of months ago with no
luck. Even though they advertsie the catalog, there are no options for
getting it.(My Grizzly catalog just arrived though).

[ ... ]

I'll try again.

You might mention that you tried before, and never got a
catalog.

[ ... ]

Obviously "small" and "accurate" don't go together on any of these
machines.

Nope -- though they do on ones like my Cameron Micro Precision
sensitive drill press. It is a maximum chuck capacity of 1/8" with the
Albrecht chuck, though a small Jacobs 3/16" chuck can be fitted to the
drill press. It is precise enough so it handles #80 drill bits (Hard to
see, even in the drill index) with no problems.

I believe I'v seen simular drill presses go for $400+ on eBay.

Mine was $150.00 new -- but that was back around 1972 or so, and
prices have increased since then. :-)

Anyway,
I can only hope that one of the $50 bench tops will allow enough
accuracy for my needs. I suppose I'll need it to be pretty accurate if
I go with the roll pin.

The roll pin expands to fit the hole, within reason. But
without special fixturing (other than the V on the top of a bench
block), I would suggest that you drill through both the sleeve and the
rod at the same time. The hole may wind up a bit off center, but it
will be the same for both parts, so the roll pin should fit through it
easily enough.

Now -- if you were using a dowel pin, you would need a very
precise hole diameter. Drill it a bit undersized, and then use a hand
reamer to take it to the proper size.

My wording probably wasn't clear enough. Basically, I'll need to turn a
4-1/2" square(1/16" thick) plate into a 3" disk that has four 1/2" wide
arms that are rounded at the ends.

Hmm ... Do they need to be a full 180 degrees of rounding, or
just a gentle curve. The latter can be turned in the lathe. The former
will take either a rotary table, or a larger mill with a corner rounding
end mill.

Technically, I can leave this piece pointed at all four ends, but I
just wanted to clean things up. I'm flexible, so I'll see what can be
done.

O.K. So just chuck it in the 4-jaw, as well centered as you can
manage, and then turn the OD to produce the curved ends, which may well
be enough.

I'll still need to get a rotary table, so I'll be searching the
internet for a visual on anything relating to a rotary table on a lathe
that has a milling attachment.

I've never seen such a combination. It is something which you
will have to make up out of parts which you can find and combine
together. A lot of machining is making special combinations of existing
tools. So -- you are highly unlikely to find such a visual. This is
one of those "figure it out for yourself" tasks.

Yes. That is why I joned a Yahoo Group "mlathemods - Mini Lathe
Modifications". Perhaps there will be some ideas there.

O.K. Good luck there. There will be things which you will have
to design for yourself.

BTW. I have a line on an Enco lathe that is supposed to have a lot of
tooling for $550. The seller says he thinks is a 9" by 16", but I don't
know if that even exists. I've only been able to find references to a 9
X 20(#308-0338).

Since I don't have an Enco catalog on hand, I've no idea whether
they currently have (or ever had) a 9x16". The shorter it is, the
lighter, as the bed adds significant weight.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
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--- Black Holes are where God is dividing by zero ---

You are obviously not familiar with a roll pin. Picture a
length of flat spring steel stock which has been rolled into a two-turn
roll. The ends are tapered a bit to make them easy to start, and they
are driven into the mating holes, with the spring expanding to grip both
the parts. They can be driven out as long as the hole goes all the way
through. They are available for relatively little money for large
quantities. With blind holes, people have managed to use a tap to
thread the ID and give a grip with a screw to pull them out.

It would seem to be more reliable(though not easier or cheaper) than
using Delrin rods.

It may well be cheaper than using Delrin rods. After all, these
are mass produced to standard diameters and lengths. Delrin tends to be
rather expensive (though something like 1/8" diameter rods would not be
that expensive, and you would simply have to turn them to the desired
final diameter and cut them to length.

I do have a lot of Delrin that I could probably make as many pins as
I'd need.(Though turning it down to 1/8" of an inch may be asking a lot
of the lathe). :-)

So I'll look that up. (Tapping is going to be a
subject unto itself that I'll have to study).

Indeed so.

The groove(which would have a 3" O.D.) would actually have to be made
in the 4" square piece.

But -- the groove could be off towards one corner, so it is just
barely grazing two sides, and that would result in the other sides
extending 1" beyond what would be the case with a centered plate. And
that would be 1.414" beyond at the corner. So -- what would have been a
5.65" diameter if centered would be closer to an 8.48" effective
diameter. This is why I specified the center point of the groove being
important.

Granted, I suspect that the groove *will* be centered, but I
want to point out the problems you can have if you make that assumption
blindly.

It'll be centered so that it'll be four inches from each of the four
sides.


Anyway,
I can only hope that one of the $50 bench tops will allow enough
accuracy for my needs. I suppose I'll need it to be pretty accurate if
I go with the roll pin.

The roll pin expands to fit the hole, within reason. But
without special fixturing (other than the V on the top of a bench
block), I would suggest that you drill through both the sleeve and the
rod at the same time. The hole may wind up a bit off center, but it
will be the same for both parts, so the roll pin should fit through it
easily enough.

What if I used a sharp punch of some sort to start, followed by a
center drill in the lathe, and then drill after that? since the 1/8"
hole is only 1/8" from the bottom I'd probably have to balance things
by using a tube with a 7/16" I.D. to fit over the rod/sleeve,
effectively lengthen it so it would slip out of the chuck.

Now -- if you were using a dowel pin, you would need a very
precise hole diameter. Drill it a bit undersized, and then use a hand
reamer to take it to the proper size.

Reamers happen to be on my shopping list. :-)

Yes. That is why I joned a Yahoo Group "mlathemods - Mini Lathe
Modifications". Perhaps there will be some ideas there.

O.K. Good luck there. There will be things which you will have
to design for yourself.

I already have a couple of tool post mods in mind. :-)

Thanks.

Darren Harris
Staten Island, New York.

According to :

[ ... ]

It would seem to be more reliable(though not easier or cheaper) than
using Delrin rods.

It may well be cheaper than using Delrin rods. After all, these
are mass produced to standard diameters and lengths. Delrin tends to be
rather expensive (though something like 1/8" diameter rods would not be
that expensive, and you would simply have to turn them to the desired
final diameter and cut them to length.

I do have a lot of Delrin that I could probably make as many pins as
I'd need.(Though turning it down to 1/8" of an inch may be asking a lot
of the lathe). :-)

Hmm ... how big is the Delrin to start? Anyway, if you are
turning a length down to 1/8", and the length is something like 9/16" or
so, it *will* bend as you try to turn it. The way to accomplish the
task is:

1) Start with a very sharp HSS tool -- ground to the angles
which are right for turning Delrin. (Note that carbide inserts
are usually a bit too dull to do this job well, though the tiny
uncoated inserts for my Compact-5/CNC tend to be quite sharp
enough. They are hard to find, and are usually quite expensive.

2) Turn only the end-most 1/8" down to 1/8" diameter.

3) Then turn the next 1/8",

4) Repeat until you have enough length to part it off to your final
length.

And -- don't have any more of the Delrin sticking out of the
chuck than you plan to turn for that one part.

[ ... ]

The roll pin expands to fit the hole, within reason. But
without special fixturing (other than the V on the top of a bench
block), I would suggest that you drill through both the sleeve and the
rod at the same time. The hole may wind up a bit off center, but it
will be the same for both parts, so the roll pin should fit through it
easily enough.

What if I used a sharp punch of some sort to start, followed by a
center drill in the lathe, and then drill after that? since the 1/8"
hole is only 1/8" from the bottom I'd probably have to balance things
by using a tube with a 7/16" I.D. to fit over the rod/sleeve,
effectively lengthen it so it would slip out of the chuck.

Hmm ... how do you plan to use the lathe for this? I thought
that the hole was from one side to the other, not into the center of the
end.

If the holes must *all* be the same distance from the end, you
will want a V-block clamped to the drill press table, with a stop to
keep you from sliding the workpiece in too far.

[ ... ]

O.K. Good luck there. There will be things which you will have
to design for yourself.

I already have a couple of tool post mods in mind. :-)

O.K.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

DoN. Nichols wrote:
According to :

[ ... ]

It would seem to be more reliable(though not easier or cheaper) than
using Delrin rods.

It may well be cheaper than using Delrin rods. After all, these
are mass produced to standard diameters and lengths. Delrin tends to be
rather expensive (though something like 1/8" diameter rods would not be
that expensive, and you would simply have to turn them to the desired
final diameter and cut them to length.

I do have a lot of Delrin that I could probably make as many pins as
I'd need.(Though turning it down to 1/8" of an inch may be asking a lot
of the lathe). :-)

Hmm ... how big is the Delrin to start? Anyway, if you are
turning a length down to 1/8", and the length is something like 9/16" or
so, it *will* bend as you try to turn it. The way to accomplish the
task is:

I have Delrin of Different shapes, but I'd use the scraps which are
basically about 1-1/2" x 2.00" X 12". I'd take it to a band saw first
to make it manageable for the lathe to turn down.

1) Start with a very sharp HSS tool -- ground to the angles
which are right for turning Delrin. (Note that carbide inserts
are usually a bit too dull to do this job well, though the tiny
uncoated inserts for my Compact-5/CNC tend to be quite sharp
enough. They are hard to find, and are usually quite expensive.

2) Turn only the end-most 1/8" down to 1/8" diameter.

3) Then turn the next 1/8",

4) Repeat until you have enough length to part it off to your final
length.

And -- don't have any more of the Delrin sticking out of the
chuck than you plan to turn for that one part.

Thanks. from what I've read, I should treat Delrin like Stainless steel
as far as the sharp tool and cutting speeds.

I also have several 4" diameter Delrin cylinders that are about a foot
long, I'll be slicing them into 3/16" or 1/4" thick disks that I'll
need to do six plunging operations involving making different sized
holes/slots in each of six equal "pie" slices.

The roll pin expands to fit the hole, within reason. But
without special fixturing (other than the V on the top of a bench
block), I would suggest that you drill through both the sleeve and the
rod at the same time. The hole may wind up a bit off center, but it
will be the same for both parts, so the roll pin should fit through it
easily enough.

What if I used a sharp punch of some sort to start, followed by a
center drill in the lathe, and then drill after that? since the 1/8"
hole is only 1/8" from the bottom I'd probably have to balance things
by using a tube with a 7/16" I.D. to fit over the rod/sleeve,
effectively lengthen it so it would slip out of the chuck.

Hmm ... how do you plan to use the lathe for this? I thought
that the hole was from one side to the other, not into the center of the
end.

I think my wording int hat last paragraph was bad, because a chuck
couldn't be used.

First I wanted to be clear that the purpose of the S.S. sleeve situated
around the turned down portion of the S.S. rod would be to keep three
1/16" plates(Delrin/stainless/Delrin) from sliding off.

Now. yes, the 11/16" long(7/16" diameter) sleeve will have the turned
down end of the rod already inserted into it so I can drill the 1/8"
diameter hole all the way through *both* at the same time. That 1/8"
diameter hole will be located only 1/8" from the end, so gripping it so
it could be drilled would pose a problem.

My idea is to make a "holder" out of a 5-1/2" long, (perhaps 1"
diameter) steel rod. I'd mill a 7/16" wide slot(1/2" deep)down about
half of it's length, so I can place the work(S.S. rod/sleeve)inside it.
The un-slotted end of this "holder" would be bolted to a face plate,
and the threaded end of the work(opposite the sleeve) would be screwed
into a 1" square block which would also be bolted to the face plate.
This would keep the work(S.S.rod/sleeve) from turning in the "holder".

After it is secure to the faceplate, drilling all the way through it
would entail a tool steel punch, followed by a center drill, followed
by a drill bit to get the 1/8" diameter hole(all the way through).

Now of course I'd have to slot and drill through the "holder" first.
:-)

If the holes must *all* be the same distance from the end, you
will want a V-block clamped to the drill press table, with a stop to
keep you from sliding the workpiece in too far.

Ok. If a $50 drill press would be easier then I will get one.(Hopefully
better than my last one).

P.S: I'd like to point out that I discovered that the 5/8" thru-hole in
my lathe was not a reference to the spindle bore. The spindle bore is
..787".

This is the part that I misinterpreted: "3-jaw self-centering chuck
(bolts to spindle: 2-3/4 inch capacity, approx. 5/8 inch dia.
thru-hole)."

Thanks a lot.

Darren Harris
Staten Island, New York.

According to :
DoN. Nichols wrote:

[ ... ]

Hmm ... how big is the Delrin to start? Anyway, if you are
turning a length down to 1/8", and the length is something like 9/16" or
so, it *will* bend as you try to turn it. The way to accomplish the
task is:

I have Delrin of Different shapes, but I'd use the scraps which are
basically about 1-1/2" x 2.00" X 12". I'd take it to a band saw first
to make it manageable for the lathe to turn down.

You are going to be making a lot more chips than parts, starting
from that size. A serious bit of waste in my book. And, you *will*
need the 4-jaw independent chuck to hold those rectangular pieces.

Hmm ... look at the MSC web site:

http://www1.mscdirect.com/CGI/NNSRIT...PMT4NO=4749765

which shows 1/8" Delrin (acetal) rod, 1 foot long, for 98 cents each.
Your choice of black, or natural (fairly white). Hmm ... that looks
like Teflon (PTFE), not Delrin (acetyl).

[ ... ]

Thanks. from what I've read, I should treat Delrin like Stainless steel
as far as the sharp tool and cutting speeds.

I also have several 4" diameter Delrin cylinders that are about a foot
long, I'll be slicing them into 3/16" or 1/4" thick disks that I'll
need to do six plunging operations involving making different sized
holes/slots in each of six equal "pie" slices.

O.K.

The roll pin expands to fit the hole, within reason. But
without special fixturing (other than the V on the top of a bench
block), I would suggest that you drill through both the sleeve and the
rod at the same time. The hole may wind up a bit off center, but it
will be the same for both parts, so the roll pin should fit through it
easily enough.

What if I used a sharp punch of some sort to start, followed by a
center drill in the lathe, and then drill after that? since the 1/8"
hole is only 1/8" from the bottom I'd probably have to balance things
by using a tube with a 7/16" I.D. to fit over the rod/sleeve,
effectively lengthen it so it would slip out of the chuck.

Hmm ... how do you plan to use the lathe for this? I thought
that the hole was from one side to the other, not into the center of the
end.

I think my wording int hat last paragraph was bad, because a chuck
couldn't be used.

First I wanted to be clear that the purpose of the S.S. sleeve situated
around the turned down portion of the S.S. rod would be to keep three
1/16" plates(Delrin/stainless/Delrin) from sliding off.

O.K.

Now. yes, the 11/16" long(7/16" diameter) sleeve will have the turned
down end of the rod already inserted into it so I can drill the 1/8"
diameter hole all the way through *both* at the same time. That 1/8"
diameter hole will be located only 1/8" from the end, so gripping it so
it could be drilled would pose a problem.

Hmm ... I would not bother with the center punch given that
setup, as long as the holder (fixture) which you describe below remains
fixed in position between workpieces.

My idea is to make a "holder" out of a 5-1/2" long, (perhaps 1"
diameter) steel rod. I'd mill a 7/16" wide slot(1/2" deep)down about
half of it's length, so I can place the work(S.S. rod/sleeve)inside it.
The un-slotted end of this "holder" would be bolted to a face plate,
and the threaded end of the work(opposite the sleeve) would be screwed
into a 1" square block which would also be bolted to the face plate.
This would keep the work(S.S.rod/sleeve) from turning in the "holder".

After it is secure to the faceplate, drilling all the way through it
would entail a tool steel punch, followed by a center drill, followed
by a drill bit to get the 1/8" diameter hole(all the way through).

As I say -- the punch probably is not necessary. Just start the
hole with the center drill. (You can get them down to 1/8" diameter,
which would make a great start for the hole.

Now of course I'd have to slot and drill through the "holder" first.
:-)

If the holes must *all* be the same distance from the end, you
will want a V-block clamped to the drill press table, with a stop to
keep you from sliding the workpiece in too far.

Ok. If a $50 drill press would be easier then I will get one.(Hopefully
better than my last one).

Your setup on the faceplate would work. But you would need to
add a counterweight on the faceplate to allow it to balance properly so
you could run at reasonable speeds for a 1/8" drill bit.

P.S: I'd like to point out that I discovered that the 5/8" thru-hole in
my lathe was not a reference to the spindle bore. The spindle bore is
.787".

O.K. That is better.

This is the part that I misinterpreted: "3-jaw self-centering chuck
(bolts to spindle: 2-3/4 inch capacity, approx. 5/8 inch dia.
thru-hole)."

So -- holding workpieces with that chuck will still limit you to
the 5/8" diameter which will fit through that chuck. Other chucks may
allow larger diameters.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

I have Delrin of Different shapes, but I'd use the scraps which are
basically about 1-1/2" x 2.00" X 12". I'd take it to a band saw first
to make it manageable for the lathe to turn down.

You are going to be making a lot more chips than parts, starting
from that size. A serious bit of waste in my book. And, you *will*
need the 4-jaw independent chuck to hold those rectangular pieces.

Yes. I'm thinking a 5" chuck with a spindle bore that is at least .787"
would be preferrable.

Hmm ... look at the MSC web site:

http://www1.mscdirect.com/CGI/NNSRIT...PMT4NO=4749765

which shows 1/8" Delrin (acetal) rod, 1 foot long, for 98 cents each.
Your choice of black, or natural (fairly white). Hmm ... that looks
like Teflon (PTFE), not Delrin (acetyl).

At 98 cents, that's obviously the better way to go. I'll save the
Delrin scrap I have for something else.

I'm assuming that Delrin would be the best choice as far as plastics,
but my first choice is your idea to use the roll pins. It would seem
that they would withstand shearing forces better.

[ ... ]

Thanks. from what I've read, I should treat Delrin like Stainless steel
as far as the sharp tool and cutting speeds.

I also have several 4" diameter Delrin cylinders that are about a foot
long, I'll be slicing them into 3/16" or 1/4" thick disks that I'll
need to do six plunging operations involving making different sized
holes/slots in each of six equal "pie" slices.

O.K.

BTW. If there is a way to do this using my lathe, the drill would have
to be at the headstock end, and I'd need something like a six-sided
collet block in something not only large enough to hold a 4" disk, but
also position it at varyng heights above the bed.

So obvious a drill press and a rotary table would be the easiest and
cheapest way to go for this.(I'd have to "overlap" drill holes to make
slots).

Now. yes, the 11/16" long(7/16" diameter) sleeve will have the turned
down end of the rod already inserted into it so I can drill the 1/8"
diameter hole all the way through *both* at the same time. That 1/8"
diameter hole will be located only 1/8" from the end, so gripping it so
it could be drilled would pose a problem.

Hmm ... I would not bother with the center punch given that
setup, as long as the holder (fixture) which you describe below remains
fixed in position between workpieces.

Yes. I'd ahve to make a dedicated face palte and holder just for this.

As I say -- the punch probably is not necessary. Just start the
hole with the center drill. (You can get them down to 1/8" diameter,
which would make a great start for the hole.

Yes. I believe that would be the #1 center drill.

Ok. If a $50 drill press would be easier then I will get one.(Hopefully
better than my last one).

Your setup on the faceplate would work. But you would need to
add a counterweight on the faceplate to allow it to balance properly so
you could run at reasonable speeds for a 1/8" drill bit.

Hmm... My original thought was to drill out the solid end of the
holder(a little at a time) which at the start would be slightly heavier
than the side holding the work and Aluminum block. until the weight on
both sides of the center axis(drill point) was equal. This would be
determined by balancing the center axis on a straight edge. But if this
is a bad idea I'll entertain your suggestion.

Thanks.

Darren Harris
Staten Island, New York.

According to :

[ ... ]

You are going to be making a lot more chips than parts, starting
from that size. A serious bit of waste in my book. And, you *will*
need the 4-jaw independent chuck to hold those rectangular pieces.

Yes. I'm thinking a 5" chuck with a spindle bore that is at least .787"
would be preferrable.

That sounds reasonable.

Hmm ... look at the MSC web site:

http://www1.mscdirect.com/CGI/NNSRIT...PMT4NO=4749765

which shows 1/8" Delrin (acetal) rod, 1 foot long, for 98 cents each.
Your choice of black, or natural (fairly white). Hmm ... that looks
like Teflon (PTFE), not Delrin (acetyl).

At 98 cents, that's obviously the better way to go. I'll save the
Delrin scrap I have for something else.

Good!

I'm assuming that Delrin would be the best choice as far as plastics,
but my first choice is your idea to use the roll pins. It would seem
that they would withstand shearing forces better.

Well ... "best choice" varies with what you need it to do. I
might consider a fiberglass/epoxy to be stronger, or even a graphite
epoxy composition. But it is not yet clear how much strength you really
*need*.

[ ... ]

I also have several 4" diameter Delrin cylinders that are about a foot
long, I'll be slicing them into 3/16" or 1/4" thick disks that I'll
need to do six plunging operations involving making different sized
holes/slots in each of six equal "pie" slices.

O.K.

BTW. If there is a way to do this using my lathe, the drill would have
to be at the headstock end, and I'd need something like a six-sided
collet block in something not only large enough to hold a 4" disk, but
also position it at varyng heights above the bed.

There are 3-jaw chucks, and 4-jaw chucks, available with 5C
collet style shanks -- designed for when a larger lathe needs to handle
smaller workpieces. Combine this with a collet block and a lathe based
milling attachment and you could probably make a go of this. The
question is how deep and how long the slots will be. If they are all
the way through, and continue out to near the edge of the disc, you will
have problems as the workpiece will collapse when enough material has
been removed.

For that -- perhaps replace the chuck with a faceplate, and find
positions in the workpiece which can accept bolts to secure it to the
faceplate (perhaps with some sacrificial material under the workpiece, so
you don't mill into the faceplate itself.

So obvious a drill press and a rotary table would be the easiest and
cheapest way to go for this.(I'd have to "overlap" drill holes to make
slots).

Smooth slots would be difficult to make this way. Drill bits
tend to bend when you're trying to partially overlap with another hole.
If you space the holes such that they are almost a full drill diameter
apart, and then make a second pass, drilling through the center of the
web between them, you will wind up with a scalloped structure which
you can then smooth out with a file.

Now. yes, the 11/16" long(7/16" diameter) sleeve will have the turned
down end of the rod already inserted into it so I can drill the 1/8"
diameter hole all the way through *both* at the same time. That 1/8"
diameter hole will be located only 1/8" from the end, so gripping it so
it could be drilled would pose a problem.

Hmm ... I would not bother with the center punch given that
setup, as long as the holder (fixture) which you describe below remains
fixed in position between workpieces.

Yes. I'd ahve to make a dedicated face palte and holder just for this.

O.K. Start collecting faceplates to fit your lathe. :-)

As I say -- the punch probably is not necessary. Just start the
hole with the center drill. (You can get them down to 1/8" diameter,
which would make a great start for the hole.

Yes. I believe that would be the #1 center drill.

That sounds right.

Ok. If a $50 drill press would be easier then I will get one.(Hopefully
better than my last one).

Your setup on the faceplate would work. But you would need to
add a counterweight on the faceplate to allow it to balance properly so
you could run at reasonable speeds for a 1/8" drill bit.

Hmm... My original thought was to drill out the solid end of the
holder(a little at a time) which at the start would be slightly heavier
than the side holding the work and Aluminum block. until the weight on
both sides of the center axis(drill point) was equal. This would be
determined by balancing the center axis on a straight edge. But if this
is a bad idea I'll entertain your suggestion.

Simply mount a lighter counterweight to one of the faceplate
slots, secure it with a bolt through the slot, and adjust it outwards
until it counterbalances the workpiece and the fixture. A lot easier
than repeated machining until you get close to the right size.

Good luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

I'm assuming that Delrin would be the best choice as far as plastics,
but my first choice is your idea to use the roll pins. It would seem
that they would withstand shearing forces better.

Well ... "best choice" varies with what you need it to do. I
might consider a fiberglass/epoxy to be stronger, or even a graphite
epoxy composition. But it is not yet clear how much strength you really
*need*.

That is why it is best to go with the strongest material I can find. A
material that will best withstand the kind of force generated(when a
3/32" wide area attermpts to shear off a 3/32", 1/8" diameter pin).

[ ... ]

I also have several 4" diameter Delrin cylinders that are about a foot
long, I'll be slicing them into 3/16" or 1/4" thick disks that I'll
need to do six plunging operations involving making different sized
holes/slots in each of six equal "pie" slices.

O.K.

BTW. If there is a way to do this using my lathe, the drill would have
to be at the headstock end, and I'd need something like a six-sided
collet block in something not only large enough to hold a 4" disk, but
also position it at varyng heights above the bed.

There are 3-jaw chucks, and 4-jaw chucks, available with 5C
collet style shanks -- designed for when a larger lathe needs to handle
smaller workpieces. Combine this with a collet block and a lathe based
milling attachment and you could probably make a go of this. The
question is how deep and how long the slots will be. If they are all
the way through, and continue out to near the edge of the disc, you will
have problems as the workpiece will collapse when enough material has
been removed.

I don't know of a better plastic for this. Basically any of six
holes/slots of various shapes(drilled all the way through the Delrin)
would fit within a 1-1/4" area and there will be a minimum space of
3/16"-1/4" between any of them. This is one reason why I was thinking a
drill press might be the best way to go.(Rpms would be a big guess at
this point).

For that -- perhaps replace the chuck with a faceplate, and find
positions in the workpiece which can accept bolts to secure it to the
faceplate (perhaps with some sacrificial material under the workpiece, so
you don't mill into the faceplate itself.

That's the plan. :-)

So obvious a drill press and a rotary table would be the easiest and
cheapest way to go for this.(I'd have to "overlap" drill holes to make
slots).

Smooth slots would be difficult to make this way. Drill bits
tend to bend when you're trying to partially overlap with another hole.
If you space the holes such that they are almost a full drill diameter
apart, and then make a second pass, drilling through the center of the
web between them, you will wind up with a scalloped structure which
you can then smooth out with a file.

Yes, perhaps "overlap" was a bad word to use. You described my
intentions. I've read about how drills catch the material on one side
when attempting to drill partly over another hole. The method you
described evens out those forces on opposite sides of the drill bit.

Your setup on the faceplate would work. But you would need to
add a counterweight on the faceplate to allow it to balance properly so
you could run at reasonable speeds for a 1/8" drill bit.

Hmm... My original thought was to drill out the solid end of the
holder(a little at a time) which at the start would be slightly heavier
than the side holding the work and Aluminum block. until the weight on
both sides of the center axis(drill point) was equal. This would be
determined by balancing the center axis on a straight edge. But if this
is a bad idea I'll entertain your suggestion.

Simply mount a lighter counterweight to one of the faceplate
slots, secure it with a bolt through the slot, and adjust it outwards
until it counterbalances the workpiece and the fixture. A lot easier
than repeated machining until you get close to the right size.


Yes, but how would I determine when it was balanced?

BTW. After some more thought, perhaps a holder made completely out of
Aluminum instead would be better. The holder/work combination would be
lighter as a result, but the heavier side would now be the half that
encompasses the work.

Thanks.

Darren Harris
Staten Island, New York.

According to :
I'm assuming that Delrin would be the best choice as far as plastics,
but my first choice is your idea to use the roll pins. It would seem
that they would withstand shearing forces better.

Well ... "best choice" varies with what you need it to do. I
might consider a fiberglass/epoxy to be stronger, or even a graphite
epoxy composition. But it is not yet clear how much strength you really
*need*.

That is why it is best to go with the strongest material I can find. A
material that will best withstand the kind of force generated(when a
3/32" wide area attermpts to shear off a 3/32", 1/8" diameter pin).

Hmm ... that depends on whether you *want* it to shear to
protect the rest of the system at some point, or whether you want it to
hold on as long as possible.

If the latter, I would suggest either a hardened dowel pin, or a
solid carbide pin.

For the former, the material is selected based on the maximum
force which you want it to transmit before it fails gracefully.
examples of this are things like the shear pin in the connection of a
propeller to an outboard motor, so the propeller survives when it hits a
rock or a log. Or a pin connecting the quick-change gearbox on a lathe
to the leadscrew, so if the carriage gets wedged, the pin will shear,
instead of losing teeth from the gearing.

[ ... ]

There are 3-jaw chucks, and 4-jaw chucks, available with 5C
collet style shanks -- designed for when a larger lathe needs to handle
smaller workpieces. Combine this with a collet block and a lathe based
milling attachment and you could probably make a go of this. The
question is how deep and how long the slots will be. If they are all
the way through, and continue out to near the edge of the disc, you will
have problems as the workpiece will collapse when enough material has
been removed.

I don't know of a better plastic for this. Basically any of six
holes/slots of various shapes(drilled all the way through the Delrin)
would fit within a 1-1/4" area and there will be a minimum space of
3/16"-1/4" between any of them. This is one reason why I was thinking a
drill press might be the best way to go.(Rpms would be a big guess at
this point).

Remember -- the slot will be scalloped -- at least until you can
file it smooth -- assuming that you have a place to run the file to do
that.

[ ... ]

Your setup on the faceplate would work. But you would need to
add a counterweight on the faceplate to allow it to balance properly so
you could run at reasonable speeds for a 1/8" drill bit.

Hmm... My original thought was to drill out the solid end of the
holder(a little at a time) which at the start would be slightly heavier
than the side holding the work and Aluminum block. until the weight on
both sides of the center axis(drill point) was equal. This would be
determined by balancing the center axis on a straight edge. But if this
is a bad idea I'll entertain your suggestion.

Simply mount a lighter counterweight to one of the faceplate
slots, secure it with a bolt through the slot, and adjust it outwards
until it counterbalances the workpiece and the fixture. A lot easier
than repeated machining until you get close to the right size.


Yes, but how would I determine when it was balanced?

Switch on the lathe spindle at a low speed, without planning to
make a cut. If the lathe doesn't try to walk off the table, keep
increasing the spindle speed to see where it does try to walk off the
table. The higher you can get the speed without things galloping
around, the better. If it does start bouncing, stop it, move the
counterweight either a bit more distant from the center or closer. Try
again. If the problem occurs at a lower speed, you moved it the wrong
way.

Since you're going to be drilling steel with only a 1/8"
diameter drill bit, you will probably want something close to the
maximum speed the lathe is capable of. (Check the SFM recommendations
for the drill bit material in the material you are drilling and compare
it to the results of calculation to determine the desired spindle speed.

BTW. After some more thought, perhaps a holder made completely out of
Aluminum instead would be better. The holder/work combination would be
lighter as a result, but the heavier side would now be the half that
encompasses the work.

Play with it until you get the right results.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

That is why it is best to go with the strongest material I can find. A
material that will best withstand the kind of force generated(when a
3/32" wide area attermpts to shear off a 3/32", 1/8" diameter pin).

Hmm ... that depends on whether you *want* it to shear to
protect the rest of the system at some point, or whether you want it to
hold on as long as possible.

If the latter, I would suggest either a hardened dowel pin, or a
solid carbide pin.

Then having the pin stay in place would again be an issue.(And
corrosion resistance is still important).

I don't know of a better plastic for this. Basically any of six
holes/slots of various shapes(drilled all the way through the Delrin)
would fit within a 1-1/4" area and there will be a minimum space of
3/16"-1/4" between any of them. This is one reason why I was thinking a
drill press might be the best way to go.(Rpms would be a big guess at
this point).

Remember -- the slot will be scalloped -- at least until you can
file it smooth -- assuming that you have a place to run the file to do
that.

I have a Dremel. :-)

Yes, but how would I determine when it was balanced?

Switch on the lathe spindle at a low speed, without planning to
make a cut. If the lathe doesn't try to walk off the table, keep
increasing the spindle speed to see where it does try to walk off the
table. The higher you can get the speed without things galloping
around, the better. If it does start bouncing, stop it, move the
counterweight either a bit more distant from the center or closer. Try
again. If the problem occurs at a lower speed, you moved it the wrong
way.

Do you know if I can I buy these counter weights or do I have to make
one myself?

Since you're going to be drilling steel with only a 1/8"
diameter drill bit, you will probably want something close to the
maximum speed the lathe is capable of. (Check the SFM recommendations
for the drill bit material in the material you are drilling and compare
it to the results of calculation to determine the desired spindle speed.

SFM recommendations?

Thanks.

Darren Harris
Staten Island, New York.

According to :
That is why it is best to go with the strongest material I can find. A
material that will best withstand the kind of force generated(when a
3/32" wide area attermpts to shear off a 3/32", 1/8" diameter pin).

Hmm ... that depends on whether you *want* it to shear to
protect the rest of the system at some point, or whether you want it to
hold on as long as possible.

If the latter, I would suggest either a hardened dowel pin, or a
solid carbide pin.

Then having the pin stay in place would again be an issue.(And
corrosion resistance is still important).

Do you *really* need that much strength? The roll pin should be
plenty. I consider the dowel pin or the solid carbide pin to be
seriously extreme conditions.

Note that with a dowel pin, you would drill the hole through the
shaft slightly undersized, and use an undersized reamer to make it a
just *barely* undersized hole.

I don't know of a better plastic for this. Basically any of six
holes/slots of various shapes(drilled all the way through the Delrin)
would fit within a 1-1/4" area and there will be a minimum space of
3/16"-1/4" between any of them. This is one reason why I was thinking a
drill press might be the best way to go.(Rpms would be a big guess at
this point).

Remember -- the slot will be scalloped -- at least until you can
file it smooth -- assuming that you have a place to run the file to do
that.

I have a Dremel. :-)

Yes -- but I don't find a hand operated Dremel to produce that
smooth a slot.

Yes, but how would I determine when it was balanced?

Switch on the lathe spindle at a low speed, without planning to
make a cut. If the lathe doesn't try to walk off the table, keep
increasing the spindle speed to see where it does try to walk off the
table. The higher you can get the speed without things galloping
around, the better. If it does start bouncing, stop it, move the
counterweight either a bit more distant from the center or closer. Try
again. If the problem occurs at a lower speed, you moved it the wrong
way.

Do you know if I can I buy these counter weights or do I have to make
one myself?

A counterweight consists of:

1) A chunk of scrap metal of about the right weight, drilled and
tapped for a bolt.

2) A bolt which fits through a slot in the faceplate.

3) Probably, a flat washer to spread out the contact of the bolt
head to the underside of the faceplate.

Of *course* you make it yourself. Until you are set up, you
don't know how much weight you will need. If it is not too much, put a
bolt through from the back, with washers on both sides of the faceplate,
and then start adding nuts to the bolt until you have the right weight.

Since you're going to be drilling steel with only a 1/8"
diameter drill bit, you will probably want something close to the
maximum speed the lathe is capable of. (Check the SFM recommendations
for the drill bit material in the material you are drilling and compare
it to the results of calculation to determine the desired spindle speed.

SFM recommendations?

Material specification, first?

1) What material you are drilling? (IIRC, it was a stainless
steel, but don't expect me to remember which stainless steel.

2) Drill bit material? You've got the choices of Chinese or
Indian pseudo-HSS, a real US (or European) made HSS, a high
cobalt steel (and which percentage), or a solid carbide drill
for starters. Also, there are various coatings TiN, TiAlN, or
various others which affect the friction, and thus the proper
speed.

Also -- some of the better ones will have polished parabolic
flutes, which will reduce the friction even more, with or
without coatings.

Drill bit grind. There are various angles available for normal
tips, plus there are split tips, which replace the chisel point
(which sort of rubs material out of the center area) with
secondary cutting edges, which will allow you to drill with a lot
less force, and will produce less heat.

I don't know which you will opt to buy.

And which lubricant/coolant will you be using? That affects
your choices as well -- and may interact with some of the other
choices. (Speaking of lubricant/coolant -- I would suggest that
you hang something behind your lathe (between it and the wall)
to avoid a line of coolant/lubricant spray forming on the wall.
(After all, someday you will be moving out of that apartment,
and not having to pay to re-plaster the wall could be a
significant savings.


Personally, I would probably go with a cobalt steel bit, with
split point, parabolic polished flutes in screw machine length,
and would spend some time looking for the best coating to use --
*if* I were going to be making thousands of these.

If I were going to make only a few, I would pick a good drill
bit from the set which I have -- or maybe a brand new one for
drilling SS -- and just select a speed which would be safe for
the bit. (But I don't buy Chinese drill bit sets, and I *do*
have a cobalt steel set of number-sized bits in screw-machine
length and split points as one of my things ready to hand.

If it comes down to chosing the *right* SFM, I would pick up my
copy of _Machinery's Handbook_ (a recent edition), and look up
what the proper SFM would be for the combination. And I would
then probably use something a bit slower, as these are for
massive production, and are a speed selected to make the optimum
tradeoff between the time the job takes and the life of the
drill bit. And the time taken to change the bit counts for more
than the cost of the bit in this equation. You won't have
production capable machinery, so don't push it.

The chart on page 1030 of the 24th edition of _Machinery's
Handbook_, for 303 SS (among some others) suggests for HSS that
you use a SFM of 20 (Opt) or 40 (Avg), with a feed of
0.015" per revolution (Opt) or 0.007"/rev (Avg)

The other column for drilling assumes indexable insert drills,
which make no sense at the size were you are working.

I'm not sure how you are going to manage a known feed rate while
drilling in the lathe, unless you mount a drill chuck to the
toolpost and set the feed gearing to accomplish that.

Anyway, for a 1/8" drill bit, and the slower SFM listed for HSS,
I see something like 611 RPM, which you would have difficulty
hitting exactly, anyway.

There seems to be no point to checking out the right speeds for
indexable carbide insert drills, as they don't make any that
small.

By comparison, the speeds for 12L14 (and other free-machining
steels) are 365 (Opt) and 740 (Avg). The slower of those two
calculates out to about 11,153 RPM. And the 12L14 will not work
harden if you pause in the drilling for a moment, while the SS
is very likely to.

So -- make a copy of _Machinery's Handbook_ one of your
purchases. The answers to *many* of your questions can be found
there, and I will henceforth assume that you have one for such
questions.


Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Do you *really* need that much strength? The roll pin should be
plenty. I consider the dowel pin or the solid carbide pin to be
seriously extreme conditions.

There really is no way todetermine howmuch force thepin would be
subjected to, which is why I said I want to go with the stongest
corrosion resistant material that would stay in the hole.(If it fails,
I'll just have to try something else).

Note that with a dowel pin, you would drill the hole through the
shaft slightly undersized, and use an undersized reamer to make it a
just *barely* undersized hole.

I've only seen bits and reamers in 1/8" size increments.

I have a Dremel. :-)

I see deburring bits and simular in the Dremel catalog. The various
Dremel tools have different bits for different operations on wood,
plastic, and metal(including stainless). I'll see if anyone at the
Dremel forum has any ideas.

SFM recommendations?

Material specification, first?

1) What material you are drilling? (IIRC, it was a stainless
steel, but don't expect me to remember which stainless steel.

303 stainless steel.

2) Drill bit material? You've got the choices of Chinese or
Indian pseudo-HSS, a real US (or European) made HSS, a high
cobalt steel (and which percentage), or a solid carbide drill
for starters. Also, there are various coatings TiN, TiAlN, or
various others which affect the friction, and thus the proper
speed.

As a firm believer(victim) of Murphy's law I tend to lean towards
getting the best within reason, even it if is over-kill. Hence, my
penchant for "over-manufacturing". :-)

As for the drill bit. The most use I can get out of it for what I paid
is a priority(using 303 stainless steel and a common standard
lubricant). So the idea is to get a general idea of what the best bits
are.

If it comes down to chosing the *right* SFM, I would pick up my
copy of _Machinery's Handbook_ (a recent edition), and look up
what the proper SFM would be for the combination. And I would
then probably use something a bit slower, as these are for
massive production, and are a speed selected to make the optimum
tradeoff between the time the job takes and the life of the
drill bit. And the time taken to change the bit counts for more
than the cost of the bit in this equation. You won't have
production capable machinery, so don't push it.

Ok. Since "time" is a complete non-factor for me, would a 20% drop in
the rated rpm and/or feed rate suffice?

The chart on page 1030 of the 24th edition of _Machinery's
Handbook_, for 303 SS (among some others) suggests for HSS that
you use a SFM of 20 (Opt) or 40 (Avg), with a feed of
0.015" per revolution (Opt) or 0.007"/rev (Avg)

The other column for drilling assumes indexable insert drills,
which make no sense at the size were you are working.

I'm not sure how you are going to manage a known feed rate while
drilling in the lathe, unless you mount a drill chuck to the
toolpost and set the feed gearing to accomplish that.

?!? Mounting a drill chuck to the tool post is something I've not read
about before.(Back to the drawing board).

So -- make a copy of _Machinery's Handbook_ one of your
purchases. The answers to *many* of your questions can be found
there, and I will henceforth assume that you have one for such
questions.

I expect that when it arrives, it'll clear up some things.(I hope that
the 25th edition is late enough). Should I also look for the guide that
is commonly advertised for use with these?

BTW. UPS left a nameless notice at my address for three consecutive
days. Now since four of the eight family's in this partcular complex
live at the same address, if there is no name then no one would know
who is supposed to be getting a package. Anyway, I get a card in the
mail UPS stating that they made three attempts to deliver a package
from MSC... I could go on and on about my past problems with UPS(and
the neighborhood driver in particular), but... (Sigh).

Thanks a lot.

Darren Harris
Staten Island, New York.

In article .com,
wrote:
[big snip]

BTW. UPS left a nameless notice at my address for three consecutive
days. Now since four of the eight family's in this partcular complex
live at the same address, if there is no name then no one would know
who is supposed to be getting a package. Anyway, I get a card in the
mail UPS stating that they made three attempts to deliver a package
from MSC... I could go on and on about my past problems with UPS(and
the neighborhood driver in particular), but... (Sigh).

What also works is to tell the sender (MSC) to mark the package to be
held at the local UPS depot for customer pickup. It also works to call
UPS upon a failed delivery attempt and ask that the package be held for
pickup. The phone number should be on the nameless note. I've done
this with computers, which are too expensive to risk just leaving them
on the front stoop.

Joe Gwinn

Joseph Gwinn wrote:
In article .com,
wrote:
[big snip]

BTW. UPS left a nameless notice at my address for three consecutive
days. Now since four of the eight family's in this partcular complex
live at the same address, if there is no name then no one would know
who is supposed to be getting a package. Anyway, I get a card in the
mail UPS stating that they made three attempts to deliver a package
from MSC... I could go on and on about my past problems with UPS(and
the neighborhood driver in particular), but... (Sigh).

What also works is to tell the sender (MSC) to mark the package to be
held at the local UPS depot for customer pickup. It also works to call
UPS upon a failed delivery attempt and ask that the package be held for
pickup. The phone number should be on the nameless note. I've done
this with computers, which are too expensive to risk just leaving them
on the front stoop.

Yes I know. The package is obviously a catalog.

Having to pick up anything via UPS is totally inconvenient for me. I'd
have to make a 2 hour round trip, not including the possibility of a
long wait on line there.


I'm surprised that the driver made "three attempts"(even though he
probably comes down my street every weekday day anyway). He doesn't
always ring the bell. And tends to put the wrong time on the notice.

One of my biggest problems with UPS is that they purposely don't inform
unaware senders that UPS doesn't deliver to Post Office boxes.(And if
you dela via eBay, you occasionally come across people who don't know).
UPS lets the package go through the system(including the "3 delivery
attempts"). They return the package to the sender and make them pay
again if they want it delivered.

Darren Harris
Staten Island, New York

According to :
Do you *really* need that much strength? The roll pin should be
plenty. I consider the dowel pin or the solid carbide pin to be
seriously extreme conditions.

There really is no way todetermine howmuch force thepin would be
subjected to, which is why I said I want to go with the stongest
corrosion resistant material that would stay in the hole.(If it fails,
I'll just have to try something else).

a) It is a joystick, right? And the pin (roll or dowel) will be in
shear only if someone is pulling up on the ball, right? Assume
the heaviest guy is say 300 pounds (as anyone heavier would
probably not be able to lift his own weight with even a
two-handed pull-up, let alone with a single-handed one.

Personally, I think that he could not shear the pin without
first breaking something else, such as the mounting of the whole
assembly.

b) If the whole game weighs 300 pounds, you probably don't *want*
someone to be able to lift it by the joystick ball, so it would
be better to use a pin which *would* shear first to protect the
rest of the machine.

c) The roll pin will be a spring grade steel, *not* a stainless,
so it would be vulnerable to corrosion anyway. (So would the
dowel pin, for that matter.) *Except* that it is not out where
it can be handled, and unless someone is going to be pouring
pints of sweat down the shaft, I see no problem.

Note that with a dowel pin, you would drill the hole through the
shaft slightly undersized, and use an undersized reamer to make it a
just *barely* undersized hole.

I've only seen bits and reamers in 1/8" size increments.

If you go to the industrial places (such as MSC, if you ever
succeed in getting the catalog), you will find that you can get
the sizes in just barely over the nominal size (probably
something like 0.0002" or so) to allow a slide fit on the dowel
pin, and also in just barely under the nominal size (by about
the same amount), so the dowel pin would be a press or drive
fit.

I have a Dremel. :-)

I see deburring bits and simular in the Dremel catalog. The various
Dremel tools have different bits for different operations on wood,
plastic, and metal(including stainless). I'll see if anyone at the
Dremel forum has any ideas.

The main problem is having a steady enough hand to control it as
you use it to open up the jagged slots.

SFM recommendations?

Material specification, first?

1) What material you are drilling? (IIRC, it was a stainless
steel, but don't expect me to remember which stainless steel.

303 stainless steel.

O.K. I think that I posted that as an example. When you get
your _Machinery's Handbook_, you can look it all up there.

2) Drill bit material? You've got the choices of Chinese or
Indian pseudo-HSS, a real US (or European) made HSS, a high
cobalt steel (and which percentage), or a solid carbide drill
for starters. Also, there are various coatings TiN, TiAlN, or
various others which affect the friction, and thus the proper
speed.

As a firm believer(victim) of Murphy's law I tend to lean towards
getting the best within reason, even it if is over-kill. Hence, my
penchant for "over-manufacturing". :-)

O.K. I would suggest going for cobalt steel bits with split
points, and unless you need the extra length, go for screw machine
length bits. They are shorter, and flex less as a result.

As for the drill bit. The most use I can get out of it for what I paid
is a priority(using 303 stainless steel and a common standard
lubricant). So the idea is to get a general idea of what the best bits
are.

You can contact the drill bit manufacturers and talk to someone
there to give you the best that *they* make, at least.

Buy the drill bits in envelopes of ten (I think that is the
standard package size for 1/8" drill bits and similar.

If it comes down to chosing the *right* SFM, I would pick up my
copy of _Machinery's Handbook_ (a recent edition), and look up
what the proper SFM would be for the combination. And I would
then probably use something a bit slower, as these are for
massive production, and are a speed selected to make the optimum
tradeoff between the time the job takes and the life of the
drill bit. And the time taken to change the bit counts for more
than the cost of the bit in this equation. You won't have
production capable machinery, so don't push it.

Ok. Since "time" is a complete non-factor for me, would a 20% drop in
the rated rpm and/or feed rate suffice?

Sure. Maybe even a 50% drop.

The chart on page 1030 of the 24th edition of _Machinery's
Handbook_, for 303 SS (among some others) suggests for HSS that
you use a SFM of 20 (Opt) or 40 (Avg), with a feed of
0.015" per revolution (Opt) or 0.007"/rev (Avg)

The other column for drilling assumes indexable insert drills,
which make no sense at the size were you are working.

I'm not sure how you are going to manage a known feed rate while
drilling in the lathe, unless you mount a drill chuck to the
toolpost and set the feed gearing to accomplish that.

?!? Mounting a drill chuck to the tool post is something I've not read
about before.(Back to the drawing board).

You can get quick-change tool holders -- at least for the AXA
size and larger) which have a Morse taper. Get one which matches the
taper in the tailstock -- or adaptor sleeves to reduce if necessary --
and you can mount the tailstock drill chuck in the toolpost, parallel to
the axis of the lathe spindle.

The major problem with it is that you have to be careful to both
adjust the height of the tool holder (only once), and you have to adjust
the position of the cross slide to be precisely in the middle of the
spindle's axis -- *every* time you go back to that after doing something
else with the lathe.

So -- make a copy of _Machinery's Handbook_ one of your
purchases. The answers to *many* of your questions can be found
there, and I will henceforth assume that you have one for such
questions.

I expect that when it arrives, it'll clear up some things.(I hope that
the 25th edition is late enough).

That is the latest that I have. I don't know what the later
editions may cover that the 25th does not. I would also suggest that
you look for a much older version, such as around the 15th or 16th, to
pick up some of the advice which has been dropped in the more recent
ones, in part thanks to the move from manual work to CNC work.

Should I also look for the guide that
is commonly advertised for use with these?

I have one for the 23rd edition, along with the main handbook,
and I've never used it. *You* may find it useful -- I don't know. My
copy came for free with the handbook -- both were a gift from someone
who was shutting down a machine shop.

BTW. UPS left a nameless notice at my address for three consecutive
days. Now since four of the eight family's in this partcular complex
live at the same address, if there is no name then no one would know
who is supposed to be getting a package. Anyway, I get a card in the
mail UPS stating that they made three attempts to deliver a package
from MSC... I could go on and on about my past problems with UPS(and
the neighborhood driver in particular), but... (Sigh).

This suggests that you need to find a *service* to receive things
for you, because MSC uses UPS for all their shipments which are not too
heavy. I suspect that it was your catalog.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

a) It is a joystick, right? And the pin (roll or dowel) will be in
shear only if someone is pulling up on the ball, right? Assume
the heaviest guy is say 300 pounds (as anyone heavier would
probably not be able to lift his own weight with even a
two-handed pull-up, let alone with a single-handed one.



Personally, I think that he could not shear the pin without
first breaking something else, such as the mounting of the whole
assembly.

Pull-up force woul dbe transmitted to the following components in
order: Ball-knob - Threaded Shaft - Pin - Shaft Sleeve - Center
Plate - Ball Bearings - Delrin Cups - Top Plate(which will be bolted
to the underside of the control panel).

b) If the whole game weighs 300 pounds, you probably don't *want*
someone to be able to lift it by the joystick ball, so it would
be better to use a pin which *would* shear first to protect the
rest of the machine.

Actually, I don't believe that in the worst case scenario the maximum
pull-up force would reach 30lbs. Even momentarily if an enraged gamer
yanks the joystick upwards.


c) The roll pin will be a spring grade steel, *not* a stainless,
so it would be vulnerable to corrosion anyway. (So would the
dowel pin, for that matter.) *Except* that it is not out where
it can be handled, and unless someone is going to be pouring
pints of sweat down the shaft, I see no problem.

I just did a redesign that would allow the pin to protrude if
necessary.

I see deburring bits and simular in the Dremel catalog. The various
Dremel tools have different bits for different operations on wood,
plastic, and metal(including stainless). I'll see if anyone at the
Dremel forum has any ideas.

The main problem is having a steady enough hand to control it as
you use it to open up the jagged slots.

No problem. :-) If it were a problem I could create a template.

O.K. I think that I posted that as an example. When you get
your _Machinery's Handbook_, you can look it all up there.

I decided to get the 27th edition:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7010710723 Hopefully
I'll have that this week.

As a firm believer(victim) of Murphy's law I tend to lean towards
getting the best within reason, even it if is over-kill. Hence, my
penchant for "over-manufacturing". :-)

O.K. I would suggest going for cobalt steel bits with split
points, and unless you need the extra length, go for screw machine
length bits. They are shorter, and flex less as a result.

Thanks.

If it comes down to chosing the *right* SFM, I would pick up my
copy of _Machinery's Handbook_ (a recent edition), and look up
what the proper SFM would be for the combination. And I would
then probably use something a bit slower, as these are for
massive production, and are a speed selected to make the optimum
tradeoff between the time the job takes and the life of the
drill bit. And the time taken to change the bit counts for more
than the cost of the bit in this equation. You won't have
production capable machinery, so don't push it.

Ok. Since "time" is a complete non-factor for me, would a 20% drop in
the rated rpm and/or feed rate suffice?

Sure. Maybe even a 50% drop.

Ok. I'll start at half the recommended rpms and work my way up.

You can get quick-change tool holders -- at least for the AXA
size and larger) which have a Morse taper. Get one which matches the
taper in the tailstock -- or adaptor sleeves to reduce if necessary --
and you can mount the tailstock drill chuck in the toolpost, parallel to
the axis of the lathe spindle.

I was looking at an MT2 tool holder. I already eyed an 3MT to 2MT
sleeve to give me flexibility:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7542413378

The major problem with it is that you have to be careful to both
adjust the height of the tool holder (only once), and you have to adjust
the position of the cross slide to be precisely in the middle of the
spindle's axis -- *every* time you go back to that after doing something
else with the lathe.

Perhaps with a 60 degree center reamer the rear of a tool holder can be
shaped to fit the center in the tail stock. Lining up would then be a
matter of backing the tool holder into the tail stock.

BTW. UPS left a nameless notice at my address for three consecutive
days. Now since four of the eight family's in this partcular complex
live at the same address, if there is no name then no one would know
who is supposed to be getting a package. Anyway, I get a card in the
mail UPS stating that they made three attempts to deliver a package
from MSC... I could go on and on about my past problems with UPS(and
the neighborhood driver in particular), but... (Sigh).

This suggests that you need to find a *service* to receive things
for you, because MSC uses UPS for all their shipments which are not too
heavy. I suspect that it was your catalog.

Yes. I had UPS divert it to my job in Manhattan.

(*Huge* catalog with *expensive* tools).

Thanks. :-)

Darren Harris
Staten Island, New York.

According to :

[ ... ]

Personally, I think that he could not shear the pin without
first breaking something else, such as the mounting of the whole
assembly.

Pull-up force woul dbe transmitted to the following components in
order: Ball-knob - Threaded Shaft - Pin - Shaft Sleeve - Center
Plate - Ball Bearings - Delrin Cups - Top Plate(which will be bolted
to the underside of the control panel).

b) If the whole game weighs 300 pounds, you probably don't *want*
someone to be able to lift it by the joystick ball, so it would
be better to use a pin which *would* shear first to protect the
rest of the machine.

Actually, I don't believe that in the worst case scenario the maximum
pull-up force would reach 30lbs. Even momentarily if an enraged gamer
yanks the joystick upwards.

O.K. Then there is no problem.

c) The roll pin will be a spring grade steel, *not* a stainless,
so it would be vulnerable to corrosion anyway. (So would the
dowel pin, for that matter.) *Except* that it is not out where
it can be handled, and unless someone is going to be pouring
pints of sweat down the shaft, I see no problem.

I just did a redesign that would allow the pin to protrude if
necessary.

O.K. But you should be able to find the roll pins in the right
length to not need to worry about that.

I see deburring bits and simular in the Dremel catalog. The various
Dremel tools have different bits for different operations on wood,
plastic, and metal(including stainless). I'll see if anyone at the
Dremel forum has any ideas.

The main problem is having a steady enough hand to control it as
you use it to open up the jagged slots.

No problem. :-) If it were a problem I could create a template.

O.K. Good luck with that.

O.K. I think that I posted that as an example. When you get
your _Machinery's Handbook_, you can look it all up there.

I decided to get the 27th edition:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7010710723 Hopefully
I'll have that this week.

O.K.

[ ... ]

Ok. Since "time" is a complete non-factor for me, would a 20% drop in
the rated rpm and/or feed rate suffice?

Sure. Maybe even a 50% drop.

Ok. I'll start at half the recommended rpms and work my way up.

O.K. That should work.

You can get quick-change tool holders -- at least for the AXA
size and larger) which have a Morse taper. Get one which matches the
taper in the tailstock -- or adaptor sleeves to reduce if necessary --
and you can mount the tailstock drill chuck in the toolpost, parallel to
the axis of the lathe spindle.

I was looking at an MT2 tool holder. I already eyed an 3MT to 2MT
sleeve to give me flexibility:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7542413378

O.K. The price does not seem too bad.

The major problem with it is that you have to be careful to both
adjust the height of the tool holder (only once), and you have to adjust
the position of the cross slide to be precisely in the middle of the
spindle's axis -- *every* time you go back to that after doing something
else with the lathe.

Perhaps with a 60 degree center reamer the rear of a tool holder can be
shaped to fit the center in the tail stock. Lining up would then be a
matter of backing the tool holder into the tail stock.

Normally, a Morse taper shank should *already* have a center
hole from when it was made. And center drills should suffice. No need
for the center reamers.

The main question is whether the back of the shank will be
within access from the center. And also, as wear builds up, there will
be slop in the position of the tailstock ram and thus the center.

[ ... ]

This suggests that you need to find a *service* to receive things
for you, because MSC uses UPS for all their shipments which are not too
heavy. I suspect that it was your catalog.

Yes. I had UPS divert it to my job in Manhattan.

O.K.

(*Huge* catalog with *expensive* tools).

And some quite inexpensive things too. Look up the roll pins in
the size which you need. I expect that a box of 100 will be quite well
under $10.00. And look at the prices of screws. Compare the prices of
a box of 100 to perhaps three or four of the same size screw in a
hardware store -- especially in Home Depot. :-)

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

The major problem with it is that you have to be careful to both
adjust the height of the tool holder (only once), and you have to adjust
the position of the cross slide to be precisely in the middle of the
spindle's axis -- *every* time you go back to that after doing something
else with the lathe.

Perhaps with a 60 degree center reamer the rear of a tool holder can be
shaped to fit the center in the tail stock. Lining up would then be a
matter of backing the tool holder into the tail stock.

Normally, a Morse taper shank should *already* have a center
hole from when it was made. And center drills should suffice. No need
for the center reamers.

The main question is whether the back of the shank will be
within access from the center. And also, as wear builds up, there will
be slop in the position of the tailstock ram and thus the center.

Hopefully I won't have to worry about that for a while.

This suggests that you need to find a *service* to receive things
for you, because MSC uses UPS for all their shipments which are not too
heavy. I suspect that it was your catalog.

Yes. I had UPS divert it to my job in Manhattan.

O.K.

(*Huge* catalog with *expensive* tools).

And some quite inexpensive things too. Look up the roll pins in
the size which you need. I expect that a box of 100 will be quite well
under $10.00. And look at the prices of screws. Compare the prices of
a box of 100 to perhaps three or four of the same size screw in a
hardware store -- especially in Home Depot. :-)

I've been carrying that catalog in my bag back and forth to work. That
should supplement the dumbell work I'll be doing for my shoulders. :-)

Thanks a lot.

Darren Harris
Staten Island, New York.