# Large lathe collet system?



## Munty Scruntfundle (23 Apr 2022)

Hi folks. I'm trying to locate, without much success, a large collet system for a lathe.

I've used a couple of ER32 and 5C chuck/collet systems with good success, but being limited to 20/30mm is becoming a problem as I'm starting to work on larger parts. It's not often I need the larger option, but when you do, you do!

The new lathe coming would be, I guess described as mid sized with good space available over the bed. Does anyone use such things? Any suggestions?

Many thanks.


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## Inspector (23 Apr 2022)

My lathe is a 13"x37" and I use a 5C chuck and collets. Anything bigger than they can handle I use the 3 or 4 jaw scroll chucks or 4 jaw independent. You could look for an ER40 or ER50 collet chuck that will let you go a little bigger. A 6 jaw would be nice for working larger thin wall work but I can't justify if for the amounts I would do.

Pete


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## Lorenzl (23 Apr 2022)

We used to use the E9 size with great success but we used it on CNC's with a collet closer pushed forward. I seem to remember Pratt Bernard? did a similar system that had strips of steel mounted in rubber ( or was it springs ) and it was closed with a normal chuck key. 

Using my good friend Google when searching for "pratt bernard lathe collet system" the collets I was thinking of come up although quite expensive.


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## Lorenzl (23 Apr 2022)

You can get "bell" collets for the 5C collet system - that's what we used to call them. You screwed a collet closer plate onto the spindle and you could have a collet up to ~ 6" but you are still restricted to the 1"? bore of the 5C spindle. Great for holding large delicate parts as it is still supported all round as you bore them out to size.

Step collet 5C


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## ChaiLatte (23 Apr 2022)

Inspector said:


> A 6 jaw would be nice for working larger thin wall work but I can't justify if for the amounts I would do.



Three jaw chucks with two piece jaws are keenly priced these days. Use soft top jaws or pie jaws bored to suit and they will grip anything. The type with tongue and groove jaws is better for a home shop than that with serrated jaws as the jaws are very easy to make.


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## Inspector (23 Apr 2022)

Basically Munty what we have said is there are multiple ways to hold objects in a metal lathe. So grit your teeth, squint and pick the one you’ll get the most out of, or pull out your bank card, buy them all and watch your money dance like a drop of water on a hot griddle.  

Pete


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## TFrench (23 Apr 2022)

What's the spindle bore on the lathe? That's probably the limiting factor. An er40 set gets you up to 26mm I think. After that there's the Pratt Burnerd multisize collet system that lorenzl mentions. The fingers are metal sprung, not rubber flex so nothing to really go wrong with it. I have a set for my lathe, the hard part is finding one with a plain back or the correct camlock fitting for your lathe AND a full set of collets. 
Pratt or bison 6 jaw chucks are pretty eye watering, however I've seen people saying good things about the sanou ones if you're prepared to do a bit of deburring and fettling to get them working nicely.
For me, I find the 5c nose on the hardinge is fine for most jobs I need collets for. Another plus for 5c is that you can get square or hex collets, as well as the flat emergency ones. Probably the most versatile system but limited by 1" max capacity.


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## jonn (24 Apr 2022)

E40 with 25 mm span big enough? Sets available from AliExpress @ about 100 Euro.








9.21US $ 51% OFF|XCAN Spring Collet Precision Collet Chuck Set ER8 ER16 ER20 ER25 ER32 ER40 For CNC Engraving Machine Milling Lathe Tool Holder|Tool Holder| - AliExpress


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www.aliexpress.com


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## TFrench (24 Apr 2022)

Had a look and it looks like a 40mm spindle bore with a D1-4 nose. The multisize system covers up to 1 1/2" so would be perfect. D1-4 ones come up occasionally on ebay


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## John Hall (24 Apr 2022)

6 jaw chuck?
what’s the maximum size you need?
and how big is your lathe?
collets are really designed to accurately hold smaller diameters…
why do you need large collets?


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## Wildman (24 Apr 2022)

I have a D


TFrench said:


> Had a look and it looks like a 40mm spindle bore with a D1-4 nose. The multisize system covers up to 1 1/2" so would be perfect. D1-4 ones come up occasionally on ebay


D13 burnard collet chuck and possibly A D14 BACKPLATE plus a set of multisize collets so maybe think about making me an offer I cannot refuse. My lathe is a D13 so if I have the other faceplate I would change it. but somehow I think it may be integral.


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## deema (24 Apr 2022)

The Pratt Bernard EC collet Chuck and collets goes up to 1 1/2”. It’s my favourite Chuck despite taking up a bit of space. Not cheap to buy secondhand.


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## cmoops2 (24 Apr 2022)

Munty Scruntfundle said:


> Hi folks. I'm trying to locate, without much success, a large collet system for a lathe.
> 
> I've used a couple of ER32 and 5C chuck/collet systems with good success, but being limited to 20/30mm is becoming a problem as I'm starting to work on larger parts. It's not often I need the larger option, but when you do, you do!
> 
> ...


I note all the answers provided presume you are talking about a metal-turning lathe - are you ?


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## John Hall (25 Apr 2022)

He does mention ER32 and 5C collets in his original post, which would point to a metal lathe, but more information would also be useful…ie what’s it for, what actual size is required, and what lathe is it for..
The more information given makes the answers so much easier and relevant..


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## sawtooth-9 (8 Aug 2022)

You really have to think about accuracy
When turning small stuff, collets are great A few thou over 1/4 inch is important
I am looking to get a collet chuck with a D14 mount for the Colchester
Two thou over 6 inches with a good 3 jaw ?
When turning big stuff decent 3 or 6 jaw chucks are great.
There is a difference between accuracy and precision.


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