Author Topic: Lathe collets.  (Read 4212 times)

Online 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

Online 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

Offline 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:
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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?

Offline 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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Online 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.

Offline 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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Online 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.

Offline 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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Online 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:

Online 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

Online Gas_mantle

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Re: Lathe collets.
« Reply #15 on: March 20, 2018, 01:26:47 PM »
All those lovely shiny new Chinese lathes resting on the sea bed  :(

Online Vixen

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Re: Lathe collets.
« Reply #16 on: March 20, 2018, 01:34:33 PM »
May they rust in peace.

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Online Gas_mantle

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Re: Lathe collets.
« Reply #17 on: March 20, 2018, 01:39:35 PM »
May they rust in peace.

Mike

Arggh that is dreadful  :D

I once worked at a factory making Chinese typewriters, the job was lousy but there were plenty of characters.

Offline crueby

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Re: Lathe collets.
« Reply #18 on: March 20, 2018, 03:47:38 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
Hmmm - it was a German ship, but did not see any DHL labels - wonder if they will announce another KFC chicken shortage...!

Offline Allen Smithee

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Re: Lathe collets.
« Reply #19 on: March 20, 2018, 07:57:40 PM »
I have the full (metric) ER32 set from Arc and a range of chucks for the lathe, tailstock and mill. They seem fine, grip well and have remained concentric & axial (which essentially covers my complete requirement set for collets). I have the ER32 myford collet chuck which RDG sell - it comes in two parts so you can mount the backplate, turn the spigot concentric and then bolt the collet chuck on to get the best concentricity. I did this with the compound laid over to about 80 degrees so I could take extremely fine cuts, and the resulting spigot fit is as near perfect as I've ever achieved. I have some 10mm PGMS bar, and when I hold that in a 10mm collet in that ER chuck  I get no measurable runout on any of my DTIs, so I'm quite happy.

As far as I'm concerned the big advantage of the ERs is,as Jason alluded, that they are spring collets which cover a range of diameters rather than fixed collets that essentially only work for the specific size. So if you bought 5C collets in 1,2,3,4,5,6,7,8,9 &10mm sizes you could grip bar that was 1,2,3,4,5,6,7,8,9 or 10mm diameter. But if you wanted to hold 1/8", 1/4", 10-swg or even just 5.5mm bar you'd have to go and buy the specific collet in that size. But if you bought the set of ER32 collets (2-20mm) you could hold ANY diameter between 2mm and 20mm. So you don't need a separate inferial set - you can hold 1/8" or 10swg in the 3.5mm collet and 1/4" in the 7mm, and if you need to hold 5.5mm bar you just use a 6mm collet. One set fits all!

OK, so they don't do square or hex collets, but if you want those covered you need to buy 'kin thousands of them because you need them in the exact sizes that your square or hex bar comes in...

AS

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Online Gas_mantle

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Re: Lathe collets.
« Reply #20 on: March 20, 2018, 08:05:53 PM »
Thanks Alan, I have bought individual collets from Arceuro to supplement my ER25 milling set and I thought they seem to do a decent job. I cant really see me damaging them so I'm inclined to think of them as a one off purchase.

I like the idea of having full set to accept any dia up to 20mm

Offline Jasonb

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Re: Lathe collets.
« Reply #21 on: March 20, 2018, 08:16:57 PM »
And with oversize ER 32 collets you can hold even bigger, handy for 24mm pistons.

As I Use as many metric cutters as I do metric I also have the smaller range of imperial ER32 as it is easier than closing metric ones right down.


Online Gas_mantle

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Re: Lathe collets.
« Reply #22 on: March 20, 2018, 08:25:07 PM »
How do you manage to hold larger than 20mm ?

Offline Jasonb

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Re: Lathe collets.
« Reply #23 on: March 20, 2018, 08:30:35 PM »
You buy oversize collets, most just do 2-20mm but you can get them from 1mm to 25mm though they cost a little more

https://www.ebay.co.uk/itm/Gloster-ER32-collet-all-sizes-2-0-25-0mm-and-1-NEW-DIN6499B-Quality-collets/370688002673?hash=item564eba0a71:m:m4t3vWF5JQmaiN5nqZZjYSg

Online Gas_mantle

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Re: Lathe collets.
« Reply #24 on: March 20, 2018, 08:35:10 PM »
You buy oversize collets, most just do 2-20mm but you can get them from 1mm to 25mm though they cost a little more

https://www.ebay.co.uk/itm/Gloster-ER32-collet-all-sizes-2-0-25-0mm-and-1-NEW-DIN6499B-Quality-collets/370688002673?hash=item564eba0a71:m:m4t3vWF5JQmaiN5nqZZjYSg

Thanks that could prove useful  :)

Online Vixen

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Re: Lathe collets.
« Reply #25 on: March 20, 2018, 09:35:13 PM »
Gloster Tooling are a very good source of equipment. I use them a lot

In addition to oversize ER32 collets they do some nice oversize ER25 collets.

The normal ER25 range stops at 16mm, Gloster offer oversize collets up to 20mm.

They may be a useful way to extend your existing ER25 capacity

Mike

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Offline zeeprogrammer

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Re: Lathe collets.
« Reply #26 on: March 20, 2018, 10:02:58 PM »
Hm. I'm wondering if my aircraft drill bits were on that ship. Got a notice that the vendor hadn't received them as expected and it would be a while longer before my order was filled.
Bummer.
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Offline Jo

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Re: Lathe collets.
« Reply #27 on: March 23, 2018, 10:05:07 AM »
The Chinese chip fat coated  collets have turned up. Initial evaluation: harness test rub with a Valorbe file shows they about the same hardness as the collet Jason gave me that came from his preferred supplier  ::)  The same test carried out on a European collet results in a completely different hardness sound/feel  :)


The other criticisms are that the slotting depth for the rear contraction slots are all over the place  :ShakeHead: No two collets seem to have the slots to the same depth when you look on the front face - A European manufacturer would have rejected these on grounds of that being an indication of inconsistent quality. And don't get me on why they have at least 3 different numbering fonts.


As I said Chinese collets are value for money. Time to remove the rancid chip fat  :disappointed:

Jo
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Offline Stuart

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Re: Lathe collets.
« Reply #28 on: March 23, 2018, 10:25:07 AM »
Jo

I am afraid the saying “they are worth what you paid for them “ or caveat emptor

My take on the eastern imports is they have enabled a lot of people to get into the hobby , not all have the cash to spend, or the space to acomadate the ex industrial machines

Yes I do have two eastern mills and a UK lathe , were they all perfect no, the sx3 has been rebuilt ground up as it was not as I would like it to be , but it’s ok now , the concern mill has the head nod that the all have its only 0.05 mm , shows up as backlash when setting z with my tshorn taster

As to collets I have a set of mm   5c .   And a lathe chuck easier to use as you don’t need the large torque tighten them ( look at the specs for a er40) and collet blocks to suit , but the collets are not import ones expensive yes hard yes

Stuart


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Online Gas_mantle

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Re: Lathe collets.
« Reply #29 on: March 23, 2018, 10:27:45 AM »
Hi Jo, I'm getting confused are these the £21 set of ebay ? Are you comparing them to the Arceuro £87 set ?

I'm expecting a set of collets to be a one off purchase that will last so I'd rather pay a bit more to get decent ones.

Offline Jo

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Re: Lathe collets.
« Reply #30 on: March 23, 2018, 10:34:00 AM »
The yellow set is the £21 ones. The one in the blue box came from Jason. As he never admits to buying from from anyone but Ketan I am assuming it is an Arc EURO one.

Jo
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Offline Jasonb

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Re: Lathe collets.
« Reply #31 on: March 23, 2018, 01:28:40 PM »
yes the one in the Blue box came from ARC though I seldom actually buy anything from them I do have a lot of their products, mostly gifts (friends & family) plus the items for the long term SX2.7 test.

Funny enough I swapped a few e-mails and had a long phone conversation with Ketan a couple of months ago when the hardness of another item cropped up. I tried a file on the one I had and it did not skid over the surface but certainly required more effort to remove metal than just plain mild steel. I tried the same file on a product from elsewhere and it did skid off. Without a hardness tester it is difficult to be accurate but the level or hardness can vary. From a bit of searching about on the net it would seem that an expensive name brand maker hardens these parts to about 5Rc more than the factory Ketan gets his items from so still hardened but just not quite a s much. It is also more than likely than another factory may harden to an even lesser degree and by taking pot luck with one of the bargain priced suppliers direct from China you may get lucky or you may not.

He will also tell you that many of these very cheap suppliers buy in stock from assorted factories that may have been rejected due to not meeting the level of quality required or just made in a factory that only makes to a low spec. They then box them all up in matching plastic boxes and sell as sets which probably explains the font and slot differences.

As Stuart says you get what you pay for - bargain bucket direct unseen you may be lucky you may not. Mid priced far eastern items made to a more consistant spec which costs the supplier hence they cost more than the bargain ones but you will get a reasonable quality that will do for most of us and can return anything that is not right. Buy named brand and get very good quality at a price and you may end up paying for a level of accuracy that is above the ability of yourself and the rest of your workshop equipment and also more than is needed to make a steam or IC engine.

You see it in all hobbies where there are some that have to have the latest set of golf clubs, this years bike, fancy hand planes etc. but if you can't hit a ball straight or use a plane you won't get much of an advantage except for what is in your mind.

J

Offline Mcgyver

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Re: Lathe collets.
« Reply #32 on: March 24, 2018, 05:32:19 PM »
Jo and others preferring 5c over ER.....

I use 2J 5C 4C, W12, 10mm and 8mm.....all variations on a theme; longer body, 3 slits, drawn in from the back, but have never turned with ER collets.  There's a slight advantage in that shapes are available such as square, hex and pot chucks but they are seldom used, at least by me.  What do you see as the advantages?

Offline john mills

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Re: Lathe collets.
« Reply #33 on: March 25, 2018, 09:30:30 AM »
the difference is more to do with accuracy at the distance from the face of the collets er 25 the distance from collet is less than for a er 32  the 5 c  the distance should be much longer   for short parts the difference may not be noticeable .It is a while since i have seen the specifications it would be good to check.   

Offline Stuart

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Re: Lathe collets.
« Reply #34 on: March 25, 2018, 09:42:00 AM »
this will make you think how you use ER collets

http://www.techniksusa.com/metal/torque_chart.htm


the line for ER 40 is why I stoped using them you need a bench fixture to get that on

for 5C its the chuck key or small wrench for the collet blocks

just my take on things


disclaimer I do use ER16 on a MT2 for the small cnc mill this is not a problem to torque up as I have a fixture to do it then they are measured to gauge line entered into the tool table and the in storage rack 10 off in all plus 4 6mm EM holders

Stuart
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Offline Jo

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Re: Lathe collets.
« Reply #35 on: March 25, 2018, 10:01:14 AM »
Collets like 5C have a single taper and can hold very short items - I have held and turned holding on a 1mm shoulder. Collets like ERs have a double taper and can close down much more than a single taper collet but if you attempt to hold something that is less than over the distance to the end of the front taper they close unevenly and the result is they "bell open" and do not hold the item  :ShakeHead:

The idea of a collet is that it holds evenly all the way round the item: the more you move away from this single size the more you are holding on a number of points rather than evenly on the entire surface. So a 1mm shoulder on a 5c collet is providing holding on 1mm x the circumference holding surface. On a ER if you stretch its capacity you are holding on 6 or 8 points on that 1mm surface - so do not be surprised that you have to use a lot more force on the nut to squeeze the collet onto your item to prevent it turning and galling.

Did I mention ERs are excellent tool holding collets :)

Jo
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Offline Jasonb

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Re: Lathe collets.
« Reply #36 on: March 25, 2018, 10:16:45 AM »
Though with an ER you do have a chance of holding any part even if it means closing right down and possibly making a plug for the back end, can't do that if you don't have the 5C size needed short of machining an emergency one or getting the 3-jaw out and cutting soft jaws.

Offline Jo

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Re: Lathe collets.
« Reply #37 on: March 25, 2018, 11:46:39 AM »
You can always use a four jaw chuck. But on short stuff you still may have to make a pot chuck.


I thought the original question was about collets for the lathe  ::)

Jo
« Last Edit: March 25, 2018, 11:49:53 AM by Jo »
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Offline Jasonb

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Re: Lathe collets.
« Reply #38 on: March 25, 2018, 01:35:24 PM »

I thought the original question was about collets for the lathe  ::)

Jo

It was you that said they were good for tool holding :insane:

Offline Jo

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Re: Lathe collets.
« Reply #39 on: March 25, 2018, 01:43:52 PM »
It was you that said they were good for tool holding :insane:

Yes holding tools in the tailstock, which is why we have ER chucks on a 2mt ;)

Jo
« Last Edit: March 25, 2018, 05:11:12 PM by Jo »
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Offline Neil-Lickfold

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Re: Lathe collets.
« Reply #40 on: January 13, 2019, 03:26:50 AM »
ER collets will only hold a part true if the part fits for the whole length of collet length. When I hold short parts in an ER collet, I use a short  piece that is the same diameter I am holding, that supports the back of the collet so it can't collapse.
5C and R8 collets will hold a short piece quite well , as long as it is within a very small amount of the collet nominal dimension.
There is a really big difference in quality and concentricity with all collets, and unless you buy the precision series of collets, the rest  are all a gamble.

Offline galland

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Re: Lathe collets.
« Reply #41 on: January 13, 2019, 01:59:45 PM »
I regularly hold parts in er collets that are under 1/8th of an inch long with out problems but like Neil said you need more support farther back in the collet. I typically slide in a faced piece of bar that is .001 smaller diameter than the piece I am working on.     Gary

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Re: Lathe collets.
« Reply #42 on: January 13, 2019, 05:20:05 PM »
ER collets will only hold a part true if the part fits for the whole length of collet length. When I hold short parts in an ER collet, I use a short  piece that is the same diameter I am holding, that supports the back of the collet so it can't collapse.
5C and R8 collets will hold a short piece quite well , as long as it is within a very small amount of the collet nominal dimension.
There is a really big difference in quality and concentricity with all collets, and unless you buy the precision series of collets, the rest  are all a gamble.

Neils comments are correct.    ER collets were originally designed to hold cutter shanks only.   Draw in collets like 5C, 3C, 8 and 10 mm    W12 and W20 have a fairly small size range.     3C and 5C have about a 0.007" range where you should use them for good accuracy.   The object going into the collet should be round, and not as cast, or Cold Rolled, or anything else not otherwise round.   

3C, 5C and 8mm or in my shop.  My Clausing is the only one that has a ER25 in it.   

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Offline RMO

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Re: Lathe collets.
« Reply #43 on: January 13, 2019, 07:29:56 PM »
About 18 months ago I picked up a set of collets in a lot of surplus tooling, inthe pictures they looked like 5C, but when I went to pick them up, it turned out they were huge.  About 5 inches tall, 2-1/4 inches in diameter at the widest point.  Turns out they were 215 collets mahe by Hardinge.  So I ended up with a set of 26 collets with no chuck.  Yesterday I finally received a chuck to fit them.  Now if I am ever going to need to turn something an 1 and 3/4 in diameter, I am set.   :whoohoo:  Actually the set includes most common sizes from 1/8 on up to 1-3/4.  I have never used collets in a lathe before, looking forward to figuring it all out.

Mike