Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Brett
 
Posts: n/a
Default Lathe Suggestions

A follow rest mounted on a sturdy tripod maybe?
Just brainstorming.


  #2   Report Post  
frank
 
Posts: n/a
Default Lathe Suggestions

There are at least three points to deal with. You have to support the
weight of the shaft, you need to keep it straight, and you need to
deal with the critical speed.

The first two are trivial.

By the way, I assume this is an axial stick-out for a through-hole
spindle, not a radial stick-out. If you have a 10' radial stick-out
you have a serious problem.

But the critical speed issue is also a serious problem. If you are
getting withing 10% of critical speed you will need to do some
real engineering. I envision lots of pillow blocks on a long
piece of large box tubing.

"Rob Hammond" wrote in message
...

Hi all

What products / ideas exist that will support a long bar (say 10 ft)
protruding from the headstock? I've had suggestions of using
1) plastic tube
2) bearing with sleeve
but wonder if these ideas are versatile enough. I guess what I'm asking
for is some kind variable diameter i.d. bearing on, perhaps, a vibration
absorbing support ...... any suggestions ???

Regards
Rob





  #3   Report Post  
Tom Young
 
Posts: n/a
Default Lathe Suggestions

On Thu, 10 Jul 2003 17:51:15 +0100, Rob Hammond wrote:

What products / ideas exist that will support a long bar (say 10 ft)
protruding from the headstock?



I've used a bungee cord wrapped around the bar and hooked to a nail in the
ceiling. Worked alright at low speeds.

-Tom

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tom Young
teyoung at attbi dot com
*To reply, remove THIS from address*
  #4   Report Post  
frank
 
Posts: n/a
Default Lathe Suggestions

Yes, it is very, very important to know how fast the stuff is
turning, exactly what it is made out of and a few other things.
We can go into a long enginering discussion about critical
speed -- perhaps that is the right thing to do.

My point was to bring up the idea, not solve the whole
problem -- not enough data was provided. I cannot be
more specific without more data.

You and I probably agree that the number one issue is a
critical speed analysis. Based on a GUESS of the
aspect ratio and material, the critical speed is probably
very low, like 10 RPM.

And yes, people are killed and machinery destroyed by
"whipping shafts".

"jim rozen" wrote in message
...
In article , "frank" says...

But the critical speed issue is also a serious problem. If you are
getting withing 10% of critical speed you will need to do some
real engineering. I envision lots of pillow blocks on a long
piece of large box tubing.


You need to be more specific about the 'critical speed'
problem.

What it means is, unless the entire shaft that protrudes
is *securely* supported along its ENTIRE length, the
machine operator will be confronted with a piece of
one inch diamter bar stock that has bent at a 90
degree angle where it emerges from the far side
of the headstock, and is WHIPPING around in
a huge circle at about 1000 rpm.

Anyone and anything in its path becomes so much
chopped meat or trash.

YOu only need to see this happen once to gain a
significant appreciation for the term 'critical.'

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================



  #5   Report Post  
Greg Dermer
 
Posts: n/a
Default Lathe Suggestions

Impressive, isn't it? Saw a piece of 3/4" steel pretty much destroy a
coolant system tank and pump and a wooden workbench. Happened real quick,
too.

(No, I wasn't the one that did it. Just an amazed bystander.)

-- Greg

"jim rozen" wrote in message
...
In article , "frank" says...

But the critical speed issue is also a serious problem. If you are
getting withing 10% of critical speed you will need to do some
real engineering. I envision lots of pillow blocks on a long
piece of large box tubing.


You need to be more specific about the 'critical speed'
problem.

What it means is, unless the entire shaft that protrudes
is *securely* supported along its ENTIRE length, the
machine operator will be confronted with a piece of
one inch diamter bar stock that has bent at a 90
degree angle where it emerges from the far side
of the headstock, and is WHIPPING around in
a huge circle at about 1000 rpm.

Anyone and anything in its path becomes so much
chopped meat or trash.

YOu only need to see this happen once to gain a
significant appreciation for the term 'critical.'

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================





  #6   Report Post  
Gary Coffman
 
Posts: n/a
Default Lathe Suggestions

On 10 Jul 2003 16:32:36 -0700, jim rozen wrote:
You need to be more specific about the 'critical speed'
problem.

What it means is, unless the entire shaft that protrudes
is *securely* supported along its ENTIRE length, the
machine operator will be confronted with a piece of
one inch diamter bar stock that has bent at a 90
degree angle where it emerges from the far side
of the headstock, and is WHIPPING around in
a huge circle at about 1000 rpm.


Ask me how I know. :-(

Gary

  #7   Report Post  
Roy Hauer
 
Posts: n/a
Default Lathe Suggestions

Ahhhhhhhhh yes, I know exactly what your talking about there. I'll
tell you how I know.

Was at work one day, and its supposedly against company policy to do
home projects, but we all know how that goes. Decent folks get
projects done on the sly others do not. Anyway a fellow came to me and
asked if I could machine a shoulder and reduce the round brass stock
he had and cut some threads on the end of it. He wanted to make a
brass shotgun cleaning rod out of some 5/16" diam brass stock he
scrounged. I said sure. I chucked it up in the lathe (about 3 1/2 - 4
feet total length. He was going to get an exact length later and cut
it to size. I machined the shoulder, and the lathe was still turning
the stock at a "resonable" speed. Someone came in the shop and he
got nervous, turned around and bumped into the speed change lever.
Lathe ran up in speed, and this brass rod bent in a 90 deg angle and
proceeded to catch him in the elbow. It was awfull. It fractured his
elbow big time. Not wanting to get me in trouble for his project, he
faked a fall out the doorway, at the back of the hanger where the
quarry tile at the threshold was always chipping off and had been
reported numerous times to the safety office as a trip and stumble
hazzard. This action finally got civil engineers to fix the doorway
thresholds tile, but his elbow has never been the same since. I have
tried numerous times to slip the lathe into a higher rnge but all it
did was grind gears, he however managed to do it just by accident.


Taught me a lesson, don;t leave anything any longer exctending out of
the lathes headstock than necessary, and don't allow anyone around you
when your using the machines......**** happens.

My pet peave is when someone just walks in and gets nect to you to
watch you make chips, or those that proceed to use the chip pan as a
foot rest while they shoot the breeze......

On Sun, 13 Jul 2003 15:19:31 GMT, (Gary Coffman)
wrote:

x-On 10 Jul 2003 16:32:36 -0700, jim rozen wrote:
x-You need to be more specific about the 'critical speed'
x-problem.
x-
x-What it means is, unless the entire shaft that protrudes
x-is *securely* supported along its ENTIRE length, the
x-machine operator will be confronted with a piece of
x-one inch diamter bar stock that has bent at a 90
x-degree angle where it emerges from the far side
x-of the headstock, and is WHIPPING around in
x-a huge circle at about 1000 rpm.
x-
x-Ask me how I know. :-(
x-
x-Gary


--
Visit my website:
http://www.frugalmachinist.com
Contents: foundry and general metal working and lots of related projects.
Regards
Roy aka Chipmaker // Foxeye
Opinions are strictly those of my wife....I have had no input whatsoever.
Remove capital A from chipmAkr for correct email address
  #8   Report Post  
DoN. Nichols
 
Posts: n/a
Default Lathe Suggestions

In article ,
Gary Coffman wrote:
On 10 Jul 2003 16:32:36 -0700, jim rozen wrote:
You need to be more specific about the 'critical speed'
problem.

What it means is, unless the entire shaft that protrudes
is *securely* supported along its ENTIRE length, the
machine operator will be confronted with a piece of
one inch diamter bar stock that has bent at a 90
degree angle where it emerges from the far side
of the headstock, and is WHIPPING around in
a huge circle at about 1000 rpm.


Ask me how I know. :-(


In my experience, I've not had any problems by using some PVC
pipe not too much larger than the stock in a cradle to constrain the
outboard end (and actually the full length outside the spindle. I've
got a 1-1/2" ID PVC pipe for 3/4" and 1" stock, and another pipe of the
same size with a pair of caps bored to be a nice fit on some smaller PVC
pipe for the thinner stuff -- 1/4", 3/16" etc).

The pipe is secured to the cradle by a Bungee cord over the
pipe.

This is enough to keep the end from starting to bend out past
some critical diameter. Once it does that, there is no stopping it, of
course.

I also don't run very fast -- typically 650 RPM for the six foot
long 3/4" brass rod, and perhaps a maximum of 1200 RPM for the really
skinny stuff.

For the 3/4" bar, I also have a Plexiglass bushing which fits in
the end of the collet drawbar to keep the bar concentric at that point.

I've now finally gotten compressed air, so I may make up some
pistons for the pipes to use as stock feed devices, so I don't have to
stop the spindle to feed stock. Just add a foot switch -- and keep the
PVC leaky enough so it won't develop full pressure, perhaps with an
intentional leak at the end of stroke.

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 ---
  #9   Report Post  
Gunner
 
Posts: n/a
Default Lathe Suggestions

On Sun, 13 Jul 2003 15:19:31 GMT, (Gary Coffman)
wrote:

On 10 Jul 2003 16:32:36 -0700, jim rozen wrote:
You need to be more specific about the 'critical speed'
problem.

What it means is, unless the entire shaft that protrudes
is *securely* supported along its ENTIRE length, the
machine operator will be confronted with a piece of
one inch diamter bar stock that has bent at a 90
degree angle where it emerges from the far side
of the headstock, and is WHIPPING around in
a huge circle at about 1000 rpm.


Ask me how I know. :-(

Gary


Sometime ago, I got stupid and in a hurry, and did just that, with a
piece of 303 5/16", about 3 feet long. Stuck it out the collet in the
Hardinge, leaving about 18" sticking out.

I would have SWORN the speed was set to about 100 rpm ( I was going to
part off several pieces)..but in fact it was set to 3000 rpm.

It got really exciting there for a minute or two, and while it didnt
harm the lathe besides removing some paint, it did cost me a nice
plastic trash can, an oiler, a nifty gouge in the wall, and a couple
years off my life.

I went into a shop a few years ago, where this had been done with a
piece of 1. 25" leadloy. The machinist had put the 5' stubb on stands
but didnt secure the stands very well. It actually moved that 16"
lathe about 4 feet before they managed to get the main power turned
off. Screwed up the floor, the walls, several workbenches and the
machinists chance to advance in that company......

Gunner

"What do you call someone in possesion of all the facts? Paranoid.-William Burroughs
  #11   Report Post  
DoN. Nichols
 
Posts: n/a
Default Lathe Suggestions

In article ,
Gunner wrote:
On 13 Jul 2003 14:01:07 -0400, (DoN. Nichols)
wrote:


I've now finally gotten compressed air, so I may make up some
pistons for the pipes to use as stock feed devices, so I don't have to
stop the spindle to feed stock. Just add a foot switch -- and keep the
PVC leaky enough so it won't develop full pressure, perhaps with an
intentional leak at the end of stroke.

Enjoy,
DoN.


If you are running a turret, its very very easy to make a parts
Puller, rather than a pusher and you can simply make up a number of
pullers for various sized stock. The advantage of a puller over a
pnuematic or hydraulic pusher really comes into play with small
diameter stock.


I thought that the pullers were better in an ASM or perhaps a
CNC with turret -- with some way to activate them automatically. I
don't see a way of activating one on my turret. (And aside from that,
I'm already using all six stations on the turret, with the feed stop
running double duty as a center drill.)

1) Stop/center drill

2) Knurl OD

3) Box tool to reduce a portion of the OD

4) Geometric die head to thread un-knurled portion of the OD

5) Drill for tap

6) Tap

(then to the carriage for grooving at the base of the thread and
parting off while I break the edges with a file.) Next setup I'll be
using one of the multi-tool Aloris holders so I can do the parting of
the current one and the grooving of the next in a single pass.

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 ---
  #12   Report Post  
jim rozen
 
Posts: n/a
Default Lathe Suggestions

In article , Gunner says...

I went into a shop a few years ago, where this had been done with a
piece of 1. 25" leadloy. The machinist had put the 5' stubb on stands
but didnt secure the stands very well. It actually moved that 16"
lathe about 4 feet before they managed to get the main power turned
off. Screwed up the floor, the walls, several workbenches and the
machinists chance to advance in that company......


Apparently it also happened at New Hampshire Ball Bearing
as well. With the same results, the guy was instantly
fired.

But this was a piece of two inch steel they make bearing
races out of. Trashed a brand new OKUMA lathe.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

  #13   Report Post  
jim rozen
 
Posts: n/a
Default Lathe Suggestions

In article , says...

I thought that the pullers were better in an ASM or perhaps a
CNC with turret -- with some way to activate them automatically. I
don't see a way of activating one on my turret. (And aside from that,
I'm already using all six stations on the turret, with the feed stop
running double duty as a center drill.)

1) Stop/center drill


Whoa stop right there Don!

You have just jogged my memory from when I was
setting up my turrret lathe. I've only done
a few parts on it so far, some were brass thumbscrews
for an antique radio, and some were some aluminum
thumbscrews for an electric timer.

But.... The real question is, *how* do you get
the stock stop (in this case, the point of your
centerdrill) to hold an accurate length when you
snap the collet closed??!

The most I can figure out is, one either

a) tries to get the variation in length of stock
protuding from the collet once it is closed, to
be about the same each time, ie. try to keep the
error small and constant, but accept it as an
overall finished part tolerance, or

b) get it close with the stop, and then use a crosslide
station, or a facing tool in the turret, to set an
absolute length that does not depend on the stock's
protrusion from the collet at the beginning of the
cycle.

I think I was seeing variation on the order of between
five and ten thou in length, when I was using the stock
stop in the turret station alone. Does this sound
about right or is there a secret skill that turret
lathe operators know to keep this smaller?

Thanks - Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

  #14   Report Post  
Gunner
 
Posts: n/a
Default Lathe Suggestions

On 13 Jul 2003 21:31:17 -0400, (DoN. Nichols)
wrote:

In article ,
Gunner wrote:
On 13 Jul 2003 14:01:07 -0400,
(DoN. Nichols)
wrote:


I've now finally gotten compressed air, so I may make up some
pistons for the pipes to use as stock feed devices, so I don't have to
stop the spindle to feed stock. Just add a foot switch -- and keep the
PVC leaky enough so it won't develop full pressure, perhaps with an
intentional leak at the end of stroke.

Enjoy,
DoN.


If you are running a turret, its very very easy to make a parts
Puller, rather than a pusher and you can simply make up a number of
pullers for various sized stock. The advantage of a puller over a
pnuematic or hydraulic pusher really comes into play with small
diameter stock.


I thought that the pullers were better in an ASM or perhaps a
CNC with turret -- with some way to activate them automatically. I
don't see a way of activating one on my turret. (And aside from that,
I'm already using all six stations on the turret, with the feed stop
running double duty as a center drill.)

1) Stop/center drill

2) Knurl OD

3) Box tool to reduce a portion of the OD

4) Geometric die head to thread un-knurled portion of the OD

5) Drill for tap

6) Tap

(then to the carriage for grooving at the base of the thread and
parting off while I break the edges with a file.) Next setup I'll be
using one of the multi-tool Aloris holders so I can do the parting of
the current one and the grooving of the next in a single pass.

Enjoy,
DoN.


In lue of the parts stop, make a puller. Simply bore a chunk of Crs or
other common metal to .005 smaller than your work, and turn the other
end to fit your turret. Then slit the bored end lengthwise.

Extend your work, close the collet. Extend the puller and it will slip
over the end of your work piece. Release the collet, and retract the
puller to the proper distance. Close the collet, retract the puller a
smidge more, pulling it off the workpiece. The first pull is marked or
set as your dead stop. Proceed with the rest of your operations. The
stub should be long enough now to slide the puller over it, retract,
and proceed. The puller is only a friction fit over the end of your
bar.

Countless machine shops use a puller every day, even on CNC,
particularly for short bars.

The second type of "bar feeder" is one that is gravity fed, and is
very easy to make in a home shop. Simply slot a piece of galvanized
pipe lengthwise, and make up a slider that fits inside, with a stub
protruding through through the slot. Attach a cord to the stub, and at
the end closest to the lathe, on the front support, attach a rotating
drum, and wrap the cord around the drum, and hang a weight from it.
As you slide in the bar, it winds up the weight. Gravity wants to pull
the weight down, putting feed pressure on the bar stock. Virtually all
of the Traub, Tornos, etc etc Swiss style screw machines use this
simple and effecient type of bar feeder.

And its a snap to make any length you have room for.

Gunner

"What do you call someone in possesion of all the facts? Paranoid.-William Burroughs
  #15   Report Post  
Gunner
 
Posts: n/a
Default Lathe Suggestions

On 13 Jul 2003 19:49:26 -0700, jim rozen
wrote:

In article , says...

I thought that the pullers were better in an ASM or perhaps a
CNC with turret -- with some way to activate them automatically. I
don't see a way of activating one on my turret. (And aside from that,
I'm already using all six stations on the turret, with the feed stop
running double duty as a center drill.)

1) Stop/center drill


Whoa stop right there Don!

You have just jogged my memory from when I was
setting up my turrret lathe. I've only done
a few parts on it so far, some were brass thumbscrews
for an antique radio, and some were some aluminum
thumbscrews for an electric timer.

But.... The real question is, *how* do you get
the stock stop (in this case, the point of your
centerdrill) to hold an accurate length when you
snap the collet closed??!

The most I can figure out is, one either

a) tries to get the variation in length of stock
protuding from the collet once it is closed, to
be about the same each time, ie. try to keep the
error small and constant, but accept it as an
overall finished part tolerance, or

b) get it close with the stop, and then use a crosslide
station, or a facing tool in the turret, to set an
absolute length that does not depend on the stock's
protrusion from the collet at the beginning of the
cycle.

I think I was seeing variation on the order of between
five and ten thou in length, when I was using the stock
stop in the turret station alone. Does this sound
about right or is there a secret skill that turret
lathe operators know to keep this smaller?

Thanks - Jim

Lots of guys make the cut off as the FIRST operation, followed by bar
advance.

One has to make the first part scrap to determine just what the
drawback of the collet will be, then all other operations are set to
that length. The second operation is generally a facing, which brings
it to proper length if the bar is a bit under or over sized, then all
other operations are done in order, followed by cutting off, which is
the start of the next cycle. This works really well if you are not
using dead length collets.

Gunner

"What do you call someone in possesion of all the facts? Paranoid.-William Burroughs


  #16   Report Post  
Gunner
 
Posts: n/a
Default Lathe Suggestions

On 14 Jul 2003 07:05:38 -0700, jim rozen
wrote:

In article , Gunner says...

One has to make the first part scrap to determine just what the
drawback of the collet will be, then all other operations are set to
that length.


OK, so at this point the best tolerance I could do would
be +/- 0.005 or so on the O/A length.

The second operation is generally a facing, which brings
it to proper length if the bar is a bit under or over sized, then all
other operations are done in order, followed by cutting off, which is
the start of the next cycle. This works really well if you are not
using dead length collets.


That obviously gets it a lot closer - but it takes another
tool location for the facing off. Either on the cross
slide or on the turret.

Jim


Correct. Lots of guys use the crosslide front position for this facing
op, With the cut off in the back position, cut off tool upside down
for chip control.

Add a tool, but get dead nuts accuracy.

Gunner

"What do you call someone in possesion of all the facts? Paranoid.-William Burroughs
  #17   Report Post  
DoN. Nichols
 
Posts: n/a
Default Lathe Suggestions

In article ,
jim rozen wrote:
In article , says...


[ ... ]

1) Stop/center drill


Whoa stop right there Don!

You have just jogged my memory from when I was
setting up my turrret lathe. I've only done
a few parts on it so far, some were brass thumbscrews
for an antique radio, and some were some aluminum
thumbscrews for an electric timer.

But.... The real question is, *how* do you get
the stock stop (in this case, the point of your
centerdrill) to hold an accurate length when you
snap the collet closed??!


First off -- the centerdrill point retracts to below the face of
the stop, so it doesn't ding the end of the work while setting length.
There was one of these shown in Moultrecht's two-volume _Machine Shop
Practice_, so I just made one of my own. Not as nice for stock stop as
the ones with a bearing-mounted rotating pad on the end, but it saves me
a station. :-)

Now -- what I do is to pull the rod stock too far by about a
half inch, then apply the lever to the point where there is some drag,
and use the turret with the stock stop to push it back (with most of the
slack taken out by the lever. If the stock is dragging on the collet,
there isn't much travel left in the collet before it locks up. Balance
by feel the drag as you approach the end of travel on the turret, and
then lock up. There will be some stock movement as you lock up, but it
is pretty minimal, and pretty consistent.

The most I can figure out is, one either

a) tries to get the variation in length of stock
protuding from the collet once it is closed, to
be about the same each time, ie. try to keep the
error small and constant, but accept it as an
overall finished part tolerance, or


This is essentially what I do -- with the drag technique
minimizing the variation.

b) get it close with the stop, and then use a crosslide
station, or a facing tool in the turret, to set an
absolute length that does not depend on the stock's
protrusion from the collet at the beginning of the
cycle.


I tried this, and decided that it wasted too much time when
doing a run of parts. As well as wasting a little bit more stock.

I think I was seeing variation on the order of between
five and ten thou in length, when I was using the stock
stop in the turret station alone. Does this sound
about right or is there a secret skill that turret
lathe operators know to keep this smaller?


Well ... I don't know about *secret*. I developed this out of
need, and didn't learn it from anyone else, but I suspect that it has
been similarly discovered by many others.

Of course, there are styles of collets which have zero stock
motion when being closed, but I understand that they are a bit less
consistent in concentricity, and the 5C with lever is what I have, so I
just learned to work with it. :-)

Thanks - Jim


You're welcome.

Now to see what others answered to your question.

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 ---
  #18   Report Post  
DoN. Nichols
 
Posts: n/a
Default Lathe Suggestions

In article ,
Gunner wrote:
On 13 Jul 2003 21:31:17 -0400, (DoN. Nichols)
wrote:

In article ,
Gunner wrote:
On 13 Jul 2003 14:01:07 -0400,
(DoN. Nichols)
wrote:


I've now finally gotten compressed air, so I may make up some
pistons for the pipes to use as stock feed devices, so I don't have to


[ ... ]

If you are running a turret, its very very easy to make a parts
Puller, rather than a pusher and you can simply make up a number of


[ ... ]

don't see a way of activating one on my turret. (And aside from that,
I'm already using all six stations on the turret, with the feed stop
running double duty as a center drill.)

1) Stop/center drill


[ ... ]

In lue of the parts stop, make a puller. Simply bore a chunk of Crs or
other common metal to .005 smaller than your work, and turn the other
end to fit your turret. Then slit the bored end lengthwise.


Sounds easy enough to make -- but that leaves me one station
short, unless there is a way to combine a center drill with the puller.
The swarf from the center drilling might interfere with the puller's
operation. Perhaps mill out the rim on the bottom, so it pours out?

Extend your work, close the collet. Extend the puller and it will slip
over the end of your work piece. Release the collet, and retract the
puller to the proper distance. Close the collet, retract the puller a
smidge more, pulling it off the workpiece. The first pull is marked or
set as your dead stop. Proceed with the rest of your operations. The
stub should be long enough now to slide the puller over it, retract,
and proceed. The puller is only a friction fit over the end of your
bar.


Hmm ... the turret that I have has only one stop per station, so
getting it *past* the stop to pick up the workpiece and then to a preset
position for the actual collet clamping might be a problem. Worth
considering if I have a setup which uses fewer stations, so the puller
first station, stock stop second, and that leaves four stations which
should be enough for some of my multi-part projects. Just this one
project which uses all stations plus one. :-)

Countless machine shops use a puller every day, even on CNC,
particularly for short bars.


There it would be particularly nice, as I have to keep a chunk
of stock on hand to act as a pusher once the bar is inside the spindle
-- or grip it with pliers and pull. :-)

The second type of "bar feeder" is one that is gravity fed, and is
very easy to make in a home shop. Simply slot a piece of galvanized
pipe lengthwise, and make up a slider that fits inside, with a stub
protruding through through the slot. Attach a cord to the stub, and at
the end closest to the lathe, on the front support, attach a rotating
drum, and wrap the cord around the drum, and hang a weight from it.
As you slide in the bar, it winds up the weight. Gravity wants to pull
the weight down, putting feed pressure on the bar stock. Virtually all
of the Traub, Tornos, etc etc Swiss style screw machines use this
simple and effecient type of bar feeder.


Nice!

And its a snap to make any length you have room for.


Ah -- the "have room for" question. :-) Six foot bar stock (as I
get from MSC) I can handle nicely. Beyond that, I see problems. :-)

Thanks,
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 ---
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
CH. Thanks AND request for some suggestions to go sealed. Francis UK diy 0 March 12th 04 02:39 PM
Shelf support suggestions please David UK diy 4 September 26th 03 10:06 AM
Collet recommendations/experience for Harrison Lathe Dean Metalworking 3 July 12th 03 07:48 AM
Warner-Swasey Turret Lathe - $250 - Upstate NY David A. Frantz Metalworking 0 July 9th 03 11:29 PM


All times are GMT +1. The time now is 01:02 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"