ER40 collet chuck on 21" swing Colchester lathe

[Overland]

I have a 21" x 80" Colchester / Harrison lathe with a 12" chuck.
It's a very large chuck for small diameter work, and high speeds with that chuck makes it hard to concentrate !

So I'm thinking a simple inexpensive option for small work might be an ER40 manual collet chuck.
I was thinking I could turn something that would fit in the the spindle nose, 0.750" per foot, and attach an ER40 chuck to that. The spindle through bore is 3.5". Or perhaps turn the ER40 form on the adapter, and buy a nut.
I believe this taper is considered self-locking, however I'm thinking a draw bar would be a good idea for safety.
Am I being overly cautious ?
Thanks
Bob

 

[rblalexander]

Absolutely use some kind of drawbar. What spindle mount does the machine have?

Sent from my SM-G973F using Tapatalk

 

[lucky7]

If it were me, I’d either have a second smaller lathe for collet work, or a 3J or Pratt Burnerd Multisize (Crawford) set on your bigger lathe. Don’t care for ER on lathe work. I found a good condition Burnerd set for my D1-6 Colchester Triumph 2000, so assume you could get one for a D1-8 or bigger Colchester.

With common hand wheel collet closers on your D1- whatever it is with your size lathe spindle adaptor you don’t need a drawbar which may be an advantage if your headstock is wide.

L7

On edit: found on ebay several Burnerd EC 25 on D1-8 chucks. Up to 2.5” capacity.

 

[CalG]

ER40 Collet Chuck Fixtures - Page 3

 

[HappyWyo]

We have full sets of collets of most types and use them occasionally. However we use our range of Chuck's much more often. We run our American lathes mostly and have from 8" to 32" Chuck's. We run 8" mostly for the same reason you are giving, but change them to 12" regularly. If you go from 12" to collet I think you will be disappointed unless tiny is all you turn.

 

[Overland]

My spindle nose is D1-11. Pretty big.
I'm fine normally with the 12" chuck, unless I get into small stuff. That's why I was thinking I could use my mill ER40 collects, when I need them.
Not looking for high performance, speed or whatever, just something more appropriate for small stuff at high speed, rather than a 12" chuck.
One other thought I had was a small chuck, but a D1-11 back plate is still about 12" diameter.
Key point is that if I pursue this idea, I should include a drawbar, or tube.
Thanks,
Bob

 

[CalG]

My spindle nose is D1-11. Pretty big.
I'm fine normally with the 12" chuck, unless I get into small stuff. That's why I was thinking I could use my mill ER40 collects, when I need them.
Not looking for high performance, speed or whatever, just something more appropriate for small stuff at high speed, rather than a 12" chuck.
One other thought I had was a small chuck, but a D1-11 back plate is still about 12" diameter.
Key point is that if I pursue this idea, I should include a drawbar, or tube.
Thanks,
Bob

ER collets are retained by a nut on the front. No draw bar is needed.

How you might mount the collet nose is up to you. I would use a lathe back plate. It could be a very handy item.

Pics of what I whipped up for the LZ330 Threaded spindle nose (much smaller than your machine) . Also , an ER50 version.

I use the rubberflex collet setup on the L1 spindle nose lathe. That works well at high spindle speeds. (High being 1200 rpm ;-)

 

[HappyWyo]

My spindle nose is D1-11. Pretty big.
I'm fine normally with the 12" chuck, unless I get into small stuff. That's why I was thinking I could use my mill ER40 collects, when I need them.
Not looking for high performance, speed or whatever, just something more appropriate for small stuff at high speed, rather than a 12" chuck.
One other thought I had was a small chuck, but a D1-11 back plate is still about 12" diameter.
Key point is that if I pursue this idea, I should include a drawbar, or tube.
Thanks,
Bob

Ok, I was just thinking about having to put that Chuck on everytime you couldn't use a collet. I know that gets old fast. You need to have a strong back.

 

[Overland]

Thanks for the good input guys.
Bob

 

[CalG]

Thanks for the good input guys.
Bob

Bob

Not to draw out this idea , but I am having a difficult time visualizing just how one would use a draw tube for ER collets in the way that the C series collets (5C, 3C) are "pulled in" . Whether lever, air, or handwheel actuated.

There are spindle nose front mounted lever actuated collect closers for some collet systems, but that is not what you are speaking of.

I guess in my limited imagination, I don't see how a through the spindle tube puller can benefit an ER collet closing system. Have you ever seen an example? Has anyone?

 

[CalG]

Got IT!

Spindle nose taper to ER-40 (X 5MT) adapter draw bolt. Wouldn't be right without one!

I would just use the spindle work depth stop rod, slightly modified to suit the adapter. (supposing a fella had one ;-)

A fella would need something very similar to send down the spindle bore to knock the adapter out anyway.

Personally, on a lathe, I would not consider a collet system that wasn't through bore to be a waste of time and steel.

 

[kenton]

Bodee MT5 ER40 Morse Taper Milling Collet Chuck Tool Holder

Are you looking for something like this?

 

[Overland]

Kind of, Kenton.
The spindle bore is 3.5", with a 0.750 / foot taper in the nose.
My thoughts were a tapered plug, with a through hole of at least 1", and an ER40 collect chuck on "the business end".
I would need to have a tube threaded into this plug, to act as a draw bar, and hold the plug in the taper.
I could use a collet chuck like this one, attached to the plug.
HHIP 3901-5036 ER-40 Collet Chuck, 100 mm Diameter x 42 mm Height: Amazon.com: Industrial & Scientific

 

[CalG]

Kind of, Kenton.
The spindle bore is 3.5", with a 0.750 / foot taper in the nose.
My thoughts were a tapered plug, with a through hole of at least 1", and an ER40 collect chuck on "the business end".
I would need to have a tube threaded into this plug, to act as a draw bar, and hold the plug in the taper.
I could use a collet chuck like this one, attached to the plug.
HHIP 3901-5036 ER-40 Collet Chuck, 100 mm Diameter x 42 mm Height: Amazon.com: Industrial & Scientific

That part from amazon is much the same as the unit shown in the pics I had attached in an earlier post.
A "better" execution would be to have an "Adjust-tru" type detail. Nothing being perfect.

Go for a through hole if you are going to do anything. Thank me later ;-)

 

[Overland]

I found a nice German 135 mm dia 3 jaw chuck I'm going to mount on the "plug", with a tubular drawbar to hold it in place.
A piece of 5-1/2" 1018, 6" long is $80 from my local steel guy. Bet someone's got a piece lying around, lol.
Bob