Author Topic: Lathe collets.  (Read 4827 times)

Offline Gas_mantle

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Lathe collets.
« on: March 19, 2018, 08:21:18 PM »
I'm kind of thinking of buying a collet chuck for my small bench lathe and had expected to go for an ER25 so that I can use the existing collets from my mill, it turns out my lathe takes ER32 which isn't a problem but does mean I'm no longer tied to buying ER.

I'm happy to stick with the ER system but have looked at others, is there any appreciable advantages with C5 or R8 systems ?

Many thanks
Peter

Offline Jasonb

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Re: Lathe collets.
« Reply #1 on: March 19, 2018, 08:33:04 PM »
Not sure why your lathe won't take an ER25 chuck, you just machine a backplate to fit the lathe and then fit an ER25 chuck to that. Downside is ER25 is quite small and probably less than your lathe spindle.

I find the shape of my 5C chuck is nice to work with on small items when you may be using a file to knock off the corners or a hand graver due to there neing nothing to catch your hands on unlike an ER nut or chuck jaws. You can get square and round 5C  collets which are nice to have in the commonly used sizes. 5C just needs a single key to tighten. Downside is they are size specific so you can't easily hold odd sized items and need a collet for each imperial and metric size you want to hold.

R8 are not used on the lathe

Offline Gas_mantle

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Re: Lathe collets.
« Reply #2 on: March 19, 2018, 08:51:43 PM »
Cheers Jason,

I could use ER25 on my lathe if I do a bit of machining but it seems a bit of a backward step to do that when an ER32 will simply bolt on and allow larger collets for pretty much the same cost.

I guess for the simple stuff I build collets may be a bit of a luxury but the idea of being able to transfer something from my lathe to my mill in a collet block without having to mess around trying to hold something small and accurately is attractive. I've tried to buy a chuck for my rotary table without success so collet blocks could be useful


Offline Thor

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Re: Lathe collets.
« Reply #3 on: March 20, 2018, 04:47:35 AM »
Hi Peter,

 I made an ER 32 collet chuck for my small lathe and it get used a lot. My small lathe has a 20mm hole through the mandrel and I already had ER 32 collets for my milling machine, I only bought a new collet nut. Here is a link to how I made my collet chuck: Link
I agree with Jason about what he says about 5C collets but a 5C chuck would have cost me far more.

Thor

Online Jo

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Re: Lathe collets.
« Reply #4 on: March 20, 2018, 07:20:42 AM »
Morning Peter,

A set of ER32 collets and a holders are cheap relative to a set of 5C. Both have their good and bad points but in my view 5C are worth the extra investment.

If you want an endorsement: My Mr Silky comes with an integral 5C collet holder on his nose and Schaublin who designed ER collets did it to hold tools on their machines, for turning they do not use ER they have the W series of collets ::)

Jo

P.S. Had to go an sit down I think I just saw Jason admit he likes 5C collets over ER for turning   :noidea:
Usus est optimum magister

Offline Jasonb

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Re: Lathe collets.
« Reply #5 on: March 20, 2018, 07:36:58 AM »
I still use my ER32 to 5C converter quite a bit Jo so I get the best of both worlds even though it does mean more overhang.

Were ER about when your old silky was made?

Online Jo

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Re: Lathe collets.
« Reply #6 on: March 20, 2018, 08:08:48 AM »
I rarely bother with ER's normally they only get used when I need to hold a 19ish or 20mm tool in one of my mills.  The spring geometry of the ER collet is well-suited only to cylindrical parts, and should not be used on square or hexagonal forms to avoid damaging the collet. Even as a surface clamping tool you have to watch the spring geometry on short lengths  :disappointed:

Were ER about when your old silky was made?

The Hardinge lathe 5C collet nose design predates Fritz Weber's ER clamping system for Schaublin which was patented in 1972.

Jo
« Last Edit: March 20, 2018, 08:15:34 AM by Jo »
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Offline Gas_mantle

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Re: Lathe collets.
« Reply #7 on: March 20, 2018, 08:26:40 AM »
Thanks for the replies :-)

I did consider making an ER32 but I've never turned threads before and not confident I could do a sufficiently accurate job. Having looked at the prices it seems like ER is the way forward for the simple stuff I do. It's a bit of a pain having to start from scratch buying new collets when I have some ER25s but I guess the extra holding capacity will be useful.

Online Jo

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Re: Lathe collets.
« Reply #8 on: March 20, 2018, 08:35:56 AM »
« Last Edit: March 20, 2018, 09:18:25 AM by Jo »
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Offline Gas_mantle

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Re: Lathe collets.
« Reply #9 on: March 20, 2018, 09:00:05 AM »
Thanks Jo, any idea if those cheap and cheerful collets are any good ?

I had thought about something like these :-

http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collets/ER32-Collets/ER32-Collets

A full set of 21 is 87 but I guess it's a one time purchase that should last me and covers all the sizes. I'll take the lathe chuck off later and have another look at the fixing as my lathe has that peculiar quick release keyhole type fitting.

Online Jo

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Re: Lathe collets.
« Reply #10 on: March 20, 2018, 09:15:36 AM »
Those also come from China. China make good collets they just don't harden them properly so they are more likely to get damaged  :-\

Its like Chinese Lathes you get what you pay for - they are cheap as chips but don't expect them to stay accurate or last as long or feel as nice as Mr Silky  :embarassed:

Think of Chinese tools/machines as disposable and you won't go far wrong  ;)

Jo

P.S. I just brought a set of those Chinese chip fat covered ER32's for drill holding  :-X
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Offline Gas_mantle

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Re: Lathe collets.
« Reply #11 on: March 20, 2018, 09:19:48 AM »
Yes, but your lathe is treadle powered isn't it ?   :stir:

Offline Jasonb

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Re: Lathe collets.
« Reply #12 on: March 20, 2018, 10:16:25 AM »
From having used the ARC collets for 7 years I can say that I have not found them to be soft and they are still as good as the day I bought them. Ketan does not buy in the cheapest that he could from China but buys from sources he knows will have consistant levels of the quality he requires. The very cheap ones can often be made to a lower spec and you don't really have much of a comeback if they do turn out to be rubber with a large run out.

I rather doubt the claimed run out on the ones Jo suggests as at 3microns that is better than high precision Rego-fix ones which would cost more for one than the whole set no wonder she drills and reams wonky holes in her flywheels :ROFL:

Offline Gas_mantle

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Re: Lathe collets.
« Reply #13 on: March 20, 2018, 10:56:37 AM »
no wonder she drills and reams wonky holes in her flywheels :ROFL:

Nah, it's that treadle powered lathe that measures in 1/1000s of 25.4mm  :pinkelephant:

Offline Jasonb

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Re: Lathe collets.
« Reply #14 on: March 20, 2018, 01:17:29 PM »


P.S. I just brought a set of those Chinese chip fat covered ER32's for drill holding  :-X

Hope they were not on this slow boat from China :-[

http://www.dailymail.co.uk/news/article-5521901/Two-huge-ships-collide-knocking-containers-sea.html