On Sat, 27 Dec 2008 12:27:44 -0600, Tim Wescott wrote:


Actually, at this point the part has been through the wars. It's still
clinging to "finish it and try it out but don't let anyone see it" -- any
more stuff-ups and it'll attain the status of "the one I screwed up on so
I could get the next one right".

Unless you are doing it for money, there's nothing particularly wrong with
having to make the odd, difficult, part a few times as a "learning"
experience.

At least, that's what I tell myself :-)


Mark Rand
RTFM

On Sun, 28 Dec 2008 00:08:01 +0000, Mark Rand wrote:

On Sat, 27 Dec 2008 12:27:44 -0600, Tim Wescott
wrote:


Actually, at this point the part has been through the wars. It's still
clinging to "finish it and try it out but don't let anyone see it" --
any more stuff-ups and it'll attain the status of "the one I screwed up
on so I could get the next one right".

Unless you are doing it for money, there's nothing particularly wrong
with having to make the odd, difficult, part a few times as a "learning"
experience.

At least, that's what I tell myself :-)

Well, yes. But I take that to mean that I should continue trying to make
the part until it is _completely_ hopeless before I start over again.

After all, if everything I did looked really good, people would think I'm
a competent machinist. I don't want them to be deceived...

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

On Dec 27, 7:08*pm, Mark Rand wrote:
On Sat, 27 Dec 2008 12:27:44 -0600, Tim Wescott wrote:
..
Unless you are doing it for money, there's nothing particularly wrong with
having to make the odd, difficult, part a few times as a "learning"
experience.
Mark Rand

Even when you are it's common to make spares. Use the "sample" part to
try each setup before risking the good one.

Tim, you can check the rigidity of the compound/top slide to see if it is
firmly supporting a cutoff/parting/grooving tool with overhang, particularly
since the compound is located near the edge of the cross slide on a Smithy.

By placing a length of stock or a bar-shaped tool about 12 inches long in
the toolholder (or turret), and applying light to moderate vertical finger
pressure at the end of the bar, any movement that is seen in the compound
would be an indication that the cutting tool has vertical movement onder the
load of cutting.
Besides the cutting tool being able to dip down while cutting, any sideways
twist will very likely break a small cutting tool of that size.

If you're compound is set parallel to the spindle axis, you may want to try
resetting it to be perpendicular to the spindle axis, or somewhere
in-between.

I realize that supporting such a short/small part with the tailstock center
on a Smithy is probably not possible. Attempting to use the extension for
the tailstock ram will probably not be worthwhile, as the overhang is too
great for the area of the base of the tailstock.

I agree with the suggestions of placing the cylinder on an expanding arbor,
this would be a great improvement over trying to chuck a hollow part.

If you have a big endmill holder (and a drawbar) that fits the spindle taper
MT4, it should be a good substitute for using a chuck.
By turning a snug-fitting stem to put in the big endmill holder, a stub (the
diameter that would hold your cylinder) could be turned for it to mount on.
If you wanted to go further, you could drill the stub, tap for a 1/8" pipe
plug or set screw, then slit the stub so it would expand inside your
cylindrical part.
Otherwise an end screw and a washer would probably suffice (with the motor
running in the forward direction).

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Tim Wescott" wrote in message
...
On Sat, 27 Dec 2008 08:55:14 +0000, Harold and Susan Vordos wrote:

That is likely a function of surface speed. The tool should have held up
for the amount of cutting involved. Try slowing down ever so slightly.
If the chips came off anything but a pale yellow or silver metal color,
you ran too fast.

As you increase rake, the tool will tend to peel the metal instead of
push it off. That lowers cutting pressure and often results in a cooler
cut----although with the reduced mass at the point of cut, the result of
the angle of rake, the tool may heat just as quickly as it did
previously. Pressure will be lower, however, and that's a good thing.

Cooling is important, but not nearly as important as lubrication. It's
virtually impossible to part dry---although a few metals will cooperate.
Leaded steels and brass tend to part dry fairly well, as does 2024
aluminum, but you're never sorry for adding lubrication. If it doesn't
do anything else, it helps chip evacuation, although there's far more
involved. You limit or eliminate chip welding, and cut cutting pressure
in ways that are hard to believe. You need not flood the cut----an
acid brush (don't use a paint brush---it doesn't hold a supply of oil
the way an acid brush does) held in the groove while cutting will make a
remarkable improvement, plus the reduced friction will yield less heat.
Overall, you'll see an improvement you can't believe. Give it a go.
You'll be pleasantly surprised. If you don't have any of the 1,1,1,
trichloroethane, try sulfur based cutting oil. It stinks, but it does a
decent job.

One more consideration. The material you're using can make a huge
difference. If you're using mild steel (C1018 up through any of the 1020
materials, hot or cold rolled), you can expect grief. You might
consider making the cylinder out of Stressproof (1144). It machines
beautifully, especially with HSS. It also has great properties.

Be certain to have relief properly ground.

It would have been interesting to hear about the lathe you're using.
Did you make mention and I missed it?

Small machines are not the best scenario for parting, although with a
narrow tool you should achieve excellent results. If you find you're
having trouble, use a narrower tool, plunge the centerline of each
groove, then, using a long travel indicator, step over and face each
side. With a sharp tool you should be able to do so without problems,
assuming the fins are reasonably thick.

How about a report on the project when you're finished? I'd be
interested in hearing the outcome. Sounds like a good one to pursue.

Harold

Sorry -- it's a Smithy "3" in one (actually 2 + excuse in one, but the
excuse is the milling section; the lathe seems to be pretty good). Other
than the compound, which seems to have some taper in the dovetail, I can
get good control of the rigidity by snugging down the jib screws.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

Errol Groff wrote:
On Fri, 26 Dec 2008 13:26:05 -0800, Tim Wescott
wrote:

Problem: A Cox 15 replacement cylinder, than needs fins.

I machined an itty bitty cutoff tool, about 50 mils wide and 300 mils
deep. It chattered. I gritted my teeth and kept feeding. It bound up,
wrenched the cylinder out of the chuck, and broke.

Fortunately the part looks to be recoverable, assuming that I can
finesse the spot where the chunks of tool dug into the steel.

But I still need to turn in those damn grooves between the fins.

Any pointers, or should I just make a new tool, do the same stupid
thing, and see if the laws of physics have changed since November? I
_did_ make sure that things were as rigid as possible, with the
exception that I probably had the cylinder sticking too far out of the
chuck, out of paranoia about hitting the jaws with the tool holder.


I don't recall were on the web I saw this idea for making a grooving
cutter for small fins but I drew up a sketch and placed it on the
NEMES web site.

http://neme-s.org/images/Slitting%20Saw.doc

I think it is a good idea but have not tried it myself.

Errol Groff

Interesting. I'm usually pretty fearless about grinding my own tooling,
so I'd be more inclined to try to make a gang slitter that would fin an
entire cylinder in one go.

But then, I said "fearless", not "smart", and first I have to get it
working the dumb slow way.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html

"Tim Wescott" wrote in message
...
Errol Groff wrote:
On Fri, 26 Dec 2008 13:26:05 -0800, Tim Wescott
wrote:

Problem: A Cox 15 replacement cylinder, than needs fins.

I machined an itty bitty cutoff tool, about 50 mils wide and 300 mils
deep. It chattered. I gritted my teeth and kept feeding. It bound up,
wrenched the cylinder out of the chuck, and broke.

Fortunately the part looks to be recoverable, assuming that I can
finesse the spot where the chunks of tool dug into the steel.

But I still need to turn in those damn grooves between the fins.

Any pointers, or should I just make a new tool, do the same stupid
thing, and see if the laws of physics have changed since November? I
_did_ make sure that things were as rigid as possible, with the
exception that I probably had the cylinder sticking too far out of the
chuck, out of paranoia about hitting the jaws with the tool holder.


I don't recall were on the web I saw this idea for making a grooving
cutter for small fins but I drew up a sketch and placed it on the
NEMES web site.

http://neme-s.org/images/Slitting%20Saw.doc

I think it is a good idea but have not tried it myself.

Errol Groff

Interesting. I'm usually pretty fearless about grinding my own tooling,
so I'd be more inclined to try to make a gang slitter that would fin an
entire cylinder in one go.

That would put so much load on the workpiece and the tool that it probably
would tear the whole setup apart. Multi-feature form tools, which were used
a lot in production years ago, usually require serious engineering of the
setup and tuning of the tool to make it work.

This may well be the way Cox made the originals, but if they did, you can be
sure they had that setup worked out by trial and error and with special
fixturing. It's not for onesies.


But then, I said "fearless", not "smart", and first I have to get it
working the dumb slow way.

That's not dumb. That's the job-shop approach.

I looked up some of my old MAP books and found another reference to making a
filler disk to go between adjacent grooves in engine cylinders. That may be
where I saw the idea originally, but I think it was in some tips I saw when
I was at _American Machinist_ 30 years ago.

--
Ed Huntress

On Mon, 29 Dec 2008 10:43:43 -0500, "Wild_Bill"
wrote:

Tim, you can check the rigidity of the compound/top slide to see if it is
firmly supporting a cutoff/parting/grooving tool with overhang, particularly
since the compound is located near the edge of the cross slide on a Smithy.

By placing a length of stock or a bar-shaped tool about 12 inches long in
the toolholder (or turret), and applying light to moderate vertical finger
pressure at the end of the bar, any movement that is seen in the compound
would be an indication that the cutting tool has vertical movement onder the
load of cutting.
Besides the cutting tool being able to dip down while cutting, any sideways
twist will very likely break a small cutting tool of that size.

If you're compound is set parallel to the spindle axis, you may want to try
resetting it to be perpendicular to the spindle axis, or somewhere
in-between.

I realize that supporting such a short/small part with the tailstock center
on a Smithy is probably not possible. Attempting to use the extension for
the tailstock ram will probably not be worthwhile, as the overhang is too
great for the area of the base of the tailstock.

I agree with the suggestions of placing the cylinder on an expanding arbor,
this would be a great improvement over trying to chuck a hollow part.

If you have a big endmill holder (and a drawbar) that fits the spindle taper
MT4, it should be a good substitute for using a chuck.
By turning a snug-fitting stem to put in the big endmill holder, a stub (the
diameter that would hold your cylinder) could be turned for it to mount on.
If you wanted to go further, you could drill the stub, tap for a 1/8" pipe
plug or set screw, then slit the stub so it would expand inside your
cylindrical part.
Otherwise an end screw and a washer would probably suffice (with the motor
running in the forward direction).


This may be considered by some as silly, but have you considered
mounting something like a Dremal with a saw blade on your cross-slide
and using the saw to slice out the fin areas while you turn the lathe
chuck VERY slowly, by hand even? That should relieve any problems
with digging in and will allow you much more control over the whole
process. Just a thought.

Jim

"Jim Chandler" wrote in message
news
SNIP----------------
This may be considered by some as silly, but have you considered
mounting something like a Dremal with a saw blade on your cross-slide
and using the saw to slice out the fin areas while you turn the lathe
chuck VERY slowly, by hand even? That should relieve any problems
with digging in and will allow you much more control over the whole
process. Just a thought.

Jim

Actually, what will work better - I've done it to make very fine features in
ebony, is to use one of those high speed carving tools - mine is 200,000
rpm - it's like a cheapened dental drill - put a straight sided bur in it,
set the lathe to turn medium slowly and then slowly advance the tool
(running, of course) into the work to the desired depth. I cut some fins in
ebony that were about .020 thick with this method - it puts almost no load
on the material. you could use a ball ended burr if you wanted a rounded
bottom to your grove - get the burrs free from your dentist - that's what I
do.

Tim Wescott wrote:
On Fri, 26 Dec 2008 16:16:48 -0600, RB wrote:

john wrote:

Tim Wescott wrote:

Problem: A Cox 15 replacement cylinder, than needs fins.

I machined an itty bitty cutoff tool, about 50 mils wide and 300 mils
deep. It chattered. I gritted my teeth and kept feeding. It bound
up, wrenched the cylinder out of the chuck, and broke.

Fortunately the part looks to be recoverable, assuming that I can
finesse the spot where the chunks of tool dug into the steel.

But I still need to turn in those damn grooves between the fins.

Any pointers, or should I just make a new tool, do the same stupid
thing, and see if the laws of physics have changed since November? I
_did_ make sure that things were as rigid as possible, with the
exception that I probably had the cylinder sticking too far out of the
chuck, out of paranoia about hitting the jaws with the tool holder.


I would recommend using coolant if possible. Make sure you have enough
side clearance on the cutoff tool.
I guess this is aluminum?
WD40 or kerosene works for cutting fluid.

It's steel. The Cox series of engines uses a one-piece cylinder finished
on the inside for a piston, threaded at each end for crankcase and head,
with 4 - 8 milling operations (one or two transfer ports, two or four
exhaust ports, and two on no flats for removing the cylinder).

My bad, I assumed aluminum

On Mon, 29 Dec 2008 09:17:43 -0800, Tim Wescott
wrote:

Errol Groff wrote:
On Fri, 26 Dec 2008 13:26:05 -0800, Tim Wescott
wrote:

Problem: A Cox 15 replacement cylinder, than needs fins.

I machined an itty bitty cutoff tool, about 50 mils wide and 300 mils
deep. It chattered. I gritted my teeth and kept feeding. It bound up,
wrenched the cylinder out of the chuck, and broke.

Fortunately the part looks to be recoverable, assuming that I can
finesse the spot where the chunks of tool dug into the steel.

But I still need to turn in those damn grooves between the fins.

Any pointers, or should I just make a new tool, do the same stupid
thing, and see if the laws of physics have changed since November? I
_did_ make sure that things were as rigid as possible, with the
exception that I probably had the cylinder sticking too far out of the
chuck, out of paranoia about hitting the jaws with the tool holder.


I don't recall were on the web I saw this idea for making a grooving
cutter for small fins but I drew up a sketch and placed it on the
NEMES web site.

http://neme-s.org/images/Slitting%20Saw.doc

I think it is a good idea but have not tried it myself.

Errol Groff

Interesting. I'm usually pretty fearless about grinding my own tooling,
so I'd be more inclined to try to make a gang slitter that would fin an
entire cylinder in one go.

But then, I said "fearless", not "smart", and first I have to get it
working the dumb slow way.


Tim....did you read the post where I accidently changed the subject line
and described a way to make your cylinder heads using the 3 jaw chuck?

The post subject line was Whoops.......with your name in it.

I didnt see an comments or people telling me I was full of ****, so
didnt know if anyone read it.

Found on google groups after cleaing out my outbox and inbox in Agent:


ID arbor is easy to make. Take a 1.5" rod, drill a hole down it for a
setscrew. Turn rod to rough (or finished ID of bore). Tap down rod
until you are witin quarter inch of far end of rod. This does NOT need
to be a precision thread. Hog out the hole with a drill a size bigger
than the normal tap drill. Makes it easier to tap.

Take a hacksaw and slit the end of the rod in 90' sections. Just a
simple cross cut. Using an allen wrench, screw in your setscrew with
the bore slid over the slotted end of the rod. until its NICE and snug
in the bore. Now you have something you can hold while you are doing
all the other functions, such as milling the ports etc etc. Should take
you about 10 minutes to make the ID arbor. Brass, steel, even aluminum
for the rod, though Id go with a piece of mild steel. You can mill the
ports right through the cylinder wall, into the rod without hurting
anything.

This of course means you should do all the second ops using a collet to
hold the arbor rod.

If you dont have collets, but a simple 3 jaw chuck with its normal
runout.... it gets more problematic. Turn your arbor in your three jaw
to bore diameter. Drill and tap for a setscrew as above, cut with a
hacksaw WITHOUT removing it from the chuck.If you remove it from the
chuck, you are ****ed.

You should have previously rough turned your cylinder from bar stock,
bored to perhoned diameter, and drilled your glow plug hole while still
held in the chuck on the end of your bar stock. Part off, and then....
Rough out 2-3 of them.

Set them aside for the moment. The bore can be honed later.

Stick your arbor rod into the chuck, and turn concentric and to bore
diameter , minus about 002

Drill for setscrew, then tap about 1" deep (assuming bore depth is say
1/2" of your cylinder..make the tapped hole 2x the depth of the bore to
be held. Do all the operations STILL HELD IN THE CHUCK.
slot in a cross pattern with a hacksaw, and screw your setscrew all the
way to the bottom of the hole Slide over your first cylinder blank..its
gonna be snug...., and then with your allen wrench through the glowplug
hole..back out the setscrew to inside the cylinder bore. That expands
the arbor of course and snugs it really tight into the cylinder. Use a
setscrew small enough that the allen wrench will go through the rough
glow plug hole of course.

Turn to diameter, then slot the fins and any other feathers that need to
be concentric to the bore. Once done, repeat with your spares.

All turning operations that need to be bore concentric are now done. You
can use the arbor to hold the cylinder to now machine your ports etc on
the mill. Repeat on the spares.

If you **** one up, you still have the others to fall back on. If you
dont **** up..you have spare cylinders.

Now you can hone the cylinders to proper diameter. Since the outside of
the cylinder is
concentric to the bore, you can turn/bore and make a very short tube
held in your 3 jaw to the diameter of the cylinder OD. Slot it and slide
in the cylinder and pinch the tube with a hose clamp. Machine hone or
hand hone under power,whatever floats your boat.

Most guys would use a collet, but if you dont have one..shrug..make work
holding tools such as the ID arbor and OD collet. The key is
concentricity throughout each operation, as dead nuts concentric as you
can get it.

They made high precision gear long before CNC was ever dreamed bout, on
lathes that a modern machinist would sneer at. Its not rocket science,
you just have to ponder on it a bit.

Gunner
"Upon Roosevelt's death in 1945, H. L. Mencken predicted in his diary
that Roosevelt would be remembered as a great president, "maybe even
alongside Washington and Lincoln," opining that Roosevelt "had every
quality that morons esteem in their heroes.""

On Mon, 29 Dec 2008 13:39:29 -0600, RB
wrote:

It's steel. The Cox series of engines uses a one-piece cylinder finished
on the inside for a piston, threaded at each end for crankcase and head,
with 4 - 8 milling operations (one or two transfer ports, two or four
exhaust ports, and two on no flats for removing the cylinder).

My bad, I assumed aluminum
================
After you have checked to make sure the gibbs/bearings/etc. are
tight, check
http://www.use-enco.com/CGI/INPDFF?P...MITEM=422-2880
http://www.use-enco.com/CGI/INPDFF?P...MITEM=422-2913
http://www1.mscdirect.com/CGI/N2DRVS...C-T7L391316886

Best tool in the box is usually an American Express card...

Gunner Asch wrote:
On Mon, 29 Dec 2008 09:17:43 -0800, Tim Wescott
wrote:

Errol Groff wrote:
On Fri, 26 Dec 2008 13:26:05 -0800, Tim Wescott
wrote:

Problem: A Cox 15 replacement cylinder, than needs fins.

I machined an itty bitty cutoff tool, about 50 mils wide and 300 mils
deep. It chattered. I gritted my teeth and kept feeding. It bound up,
wrenched the cylinder out of the chuck, and broke.

Fortunately the part looks to be recoverable, assuming that I can
finesse the spot where the chunks of tool dug into the steel.

But I still need to turn in those damn grooves between the fins.

Any pointers, or should I just make a new tool, do the same stupid
thing, and see if the laws of physics have changed since November? I
_did_ make sure that things were as rigid as possible, with the
exception that I probably had the cylinder sticking too far out of the
chuck, out of paranoia about hitting the jaws with the tool holder.

I don't recall were on the web I saw this idea for making a grooving
cutter for small fins but I drew up a sketch and placed it on the
NEMES web site.

http://neme-s.org/images/Slitting%20Saw.doc

I think it is a good idea but have not tried it myself.

Errol Groff
Interesting. I'm usually pretty fearless about grinding my own tooling,
so I'd be more inclined to try to make a gang slitter that would fin an
entire cylinder in one go.

But then, I said "fearless", not "smart", and first I have to get it
working the dumb slow way.


Tim....did you read the post where I accidently changed the subject line
and described a way to make your cylinder heads using the 3 jaw chuck?

The post subject line was Whoops.......with your name in it.

I didnt see an comments or people telling me I was full of ****, so
didnt know if anyone read it.

Found on google groups after cleaing out my outbox and inbox in Agent:


ID arbor is easy to make. Take a 1.5" rod, drill a hole down it for a
setscrew. Turn rod to rough (or finished ID of bore). Tap down rod
until you are witin quarter inch of far end of rod. This does NOT need
to be a precision thread. Hog out the hole with a drill a size bigger
than the normal tap drill. Makes it easier to tap.

Take a hacksaw and slit the end of the rod in 90' sections. Just a
simple cross cut. Using an allen wrench, screw in your setscrew with
the bore slid over the slotted end of the rod. until its NICE and snug
in the bore. Now you have something you can hold while you are doing
all the other functions, such as milling the ports etc etc. Should take
you about 10 minutes to make the ID arbor. Brass, steel, even aluminum
for the rod, though Id go with a piece of mild steel. You can mill the
ports right through the cylinder wall, into the rod without hurting
anything.

This of course means you should do all the second ops using a collet to
hold the arbor rod.

If you dont have collets, but a simple 3 jaw chuck with its normal
runout.... it gets more problematic. Turn your arbor in your three jaw
to bore diameter. Drill and tap for a setscrew as above, cut with a
hacksaw WITHOUT removing it from the chuck.If you remove it from the
chuck, you are ****ed.

You should have previously rough turned your cylinder from bar stock,
bored to perhoned diameter, and drilled your glow plug hole while still
held in the chuck on the end of your bar stock. Part off, and then....
Rough out 2-3 of them.

Set them aside for the moment. The bore can be honed later.

Stick your arbor rod into the chuck, and turn concentric and to bore
diameter , minus about 002

Drill for setscrew, then tap about 1" deep (assuming bore depth is say
1/2" of your cylinder..make the tapped hole 2x the depth of the bore to
be held. Do all the operations STILL HELD IN THE CHUCK.
slot in a cross pattern with a hacksaw, and screw your setscrew all the
way to the bottom of the hole Slide over your first cylinder blank..its
gonna be snug...., and then with your allen wrench through the glowplug
hole..back out the setscrew to inside the cylinder bore. That expands
the arbor of course and snugs it really tight into the cylinder. Use a
setscrew small enough that the allen wrench will go through the rough
glow plug hole of course.

Turn to diameter, then slot the fins and any other feathers that need to
be concentric to the bore. Once done, repeat with your spares.

All turning operations that need to be bore concentric are now done. You
can use the arbor to hold the cylinder to now machine your ports etc on
the mill. Repeat on the spares.

If you **** one up, you still have the others to fall back on. If you
dont **** up..you have spare cylinders.

Now you can hone the cylinders to proper diameter. Since the outside of
the cylinder is
concentric to the bore, you can turn/bore and make a very short tube
held in your 3 jaw to the diameter of the cylinder OD. Slot it and slide
in the cylinder and pinch the tube with a hose clamp. Machine hone or
hand hone under power,whatever floats your boat.

Most guys would use a collet, but if you dont have one..shrug..make work
holding tools such as the ID arbor and OD collet. The key is
concentricity throughout each operation, as dead nuts concentric as you
can get it.

They made high precision gear long before CNC was ever dreamed bout, on
lathes that a modern machinist would sneer at. Its not rocket science,
you just have to ponder on it a bit.

I saw two with the same text and different headers, and responded to one.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html

"Ed Huntress" wrote:

Interesting. I'm usually pretty fearless about grinding my own tooling,
so I'd be more inclined to try to make a gang slitter that would fin an
entire cylinder in one go.

That would put so much load on the workpiece and the tool that it probably
would tear the whole setup apart. Multi-feature form tools, which were used
a lot in production years ago, usually require serious engineering of the
setup and tuning of the tool to make it work.


We use carbide gang groovers in a few of our lathes at work. On a good day if the
programmer gets too agressive the spindle amp faults. On a bad day the poly belts slip
and burn up first. What a mess having plastic stuck to a poly vee style pulley.

Wes

"Wes" wrote in message
...
"Ed Huntress" wrote:

Interesting. I'm usually pretty fearless about grinding my own tooling,
so I'd be more inclined to try to make a gang slitter that would fin an
entire cylinder in one go.

That would put so much load on the workpiece and the tool that it probably
would tear the whole setup apart. Multi-feature form tools, which were
used
a lot in production years ago, usually require serious engineering of the
setup and tuning of the tool to make it work.


We use carbide gang groovers in a few of our lathes at work. On a good
day if the
programmer gets too agressive the spindle amp faults. On a bad day the
poly belts slip
and burn up first. What a mess having plastic stuck to a poly vee style
pulley.

Wes

Yuck! Imagine what it's like with a little hobby lathe.

My uncle, who taught shop, had an exceptional student who made a whole set
of form tools to turn chessmen, in a single plunge-cut each. They ran in a
10" South Bend. He'd make one set of brass and another of aluminum.

It was such a job, getting the clearances and reliefs right so they would
cut in that little lathe, that it took him almost a whole term in school to
get them to run right. And they had a very nice optical profile grinder to
do the job.

--
Ed Huntress

Tim Wescott wrote:


After all, if everything I did looked really good, people would think I'm
a competent machinist. I don't want them to be deceived...


Tim:

Fins? Fins?, did somebody say fins?

http://cuttingtoolengineering.com/in...s.php?irid=114

Obviously overkill for your project, but pretty neat, eh?

--
BottleBob
http://home.earthlink.net/~bottlbob

wow- I want that thing they made for the demo - that is a very cool little
object


"BottleBob" wrote in message
...


Tim Wescott wrote:


After all, if everything I did looked really good, people would think I'm
a competent machinist. I don't want them to be deceived...


Tim:

Fins? Fins?, did somebody say fins?

http://cuttingtoolengineering.com/in...s.php?irid=114

Obviously overkill for your project, but pretty neat, eh?

--
BottleBob
http://home.earthlink.net/~bottlbob




** Posted from http://www.teranews.com **

Just amazing, Bob. I was thinkin', so what's the globe on the end, and this
guy's just babbling about fins, those are a couple of disks, and then.. we
get to see fins

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"BottleBob" wrote in message
...


Tim Wescott wrote:


After all, if everything I did looked really good, people would think I'm
a competent machinist. I don't want them to be deceived...


Tim:

Fins? Fins?, did somebody say fins?

http://cuttingtoolengineering.com/in...s.php?irid=114

Obviously overkill for your project, but pretty neat, eh?

--
BottleBob
http://home.earthlink.net/~bottlbob