Collet Chucks on the Lath

[martyn nutlandParticipant @martynnutland79495]

[martyn nutlandParticipant @martynnutland79495]

Simple question if I may.

I've been using, with vert satisfactory results, a collet chuck with ER32 collets to hold tools (endmills, drills etc) on my milling machine (Warco Economy.).

Could I use the same chuck (No 3 Morse Taper) fitted to the head stock spindle of my lathe (Chester Super B) with a draw-bar passing through the mandrel to hold material like bar up to the ER32 collet maximum diameter? Or do I need a special collet chuck for the lathe?

Best Wishes to everyone.

Martyn

[John RuddParticipant @johnrudd16576]

Simple answer is yes you can…

Drawback is, you are restricted to the length of material the chuck will accomodate….ideal for short stubby bits…

Edited By John Rudd on 12/08/2015 20:25:23

[John HinkleyParticipant @johnhinkley26699]

I'm not familiar with your lathe, Martyn, but if it's like the Chester Super mill/lathe combination machine currently advertised on the Chester web site, it has an MT3 taper in the spindle. So, the short answer to your question is – Yes. In fact I've just done the same thing with my lathe. I ordered a Warco VMC mill last week with R8 spindle. My previous bench top mill had an MT3 spindle so my ER25 and ER32 chucks as well as my boring head were in need of new arbors.. These arrived a couple of weeks ago from Hong Kong and the MT3 are to be pressed into use in the lathe as and when required. A length of studding and a bung in the other end and away I go!

Good luck. Your lathe manual should tell you what the spindle taper is.

John

John (Rudd ) just beat me to it!  Being a short, stubby bit myself, I can confirm it's ideal!

Edited By John Hinkley on 12/08/2015 20:31:09

Edited By John Hinkley on 12/08/2015 20:32:04

[VicParticipant @vic]

A dedicated Lathe chuck is best as John alluded to so that long stock can pass through the head stock spindle.

[duncan webster 1Participant @duncanwebster1]

If you make the drawbar out of a piece of pipe you will be able to hold long lengths of small stuff

[pgk pgkParticipant @pgkpgk17461]

..you can also get taper converters and screw-in tangs should you wish to use the collet set in the tailstock.

[martyn nutlandParticipant @martynnutland79495]

Thanks for all that reassurance everyone.

The Chester has a 3MT taper in the headstock and I have on occasion successfully used small scroll chucks with that fitment or with the 2MT variant and a convertor.

I plan to use the lead screw from an ancient Furnival book-binder's guillotine I scrapped to make the draw bar as its dimensions seem about perfect and the result might be a bit more elegant than studding!

I gather though, it's important not to pull up the draw bar too tightly in these situations (only about a quarter turn) so as not to get the taper gripping too tightly as knocking the tool out will require much bashing which, of course, is not good for the headstock bearings.

Thanks again for all the advice.

Martyn

[IanTParticipant @iant]

Hi Martyn,

I think your question has been answered (It's "Yes" ) but I'm aware others (new to this game) may also be reading this thread.

So for them – I'd like to point out that the length of material you can hold in any "MT" based collet chuck will be limited by the depth available at the back of the collet 'cone' (using a hollow draw bar or not). Of course it will hold shorter work very securely and it's repeatability (for second operation work) will be better than most 3-Jaw chucks.

However, in the longer term (and for anyone stating from scratch with ER collets on a lathe) I believe that the ER chuck type that mounts on a back-plate is generally a better long term solution.

I standardised on ER collets (I use both ER32 & ER16) some time ago and have a MT2 mounted ER collet chuck as well as a number of ER chucks on back-plates (plus an ER Spin Indexer and various ER collet blocks etc.).

I generally prefer to use a MT2 'Clarkson' chuck on my milling machines but the MT2 ER32 does get used where I don't have a suitable Clarkson collet or the cutter is unthreaded. I know I've also used it in the tailstock of my S7 but I can't off hand recall quite why now, as the drill chuck is my first go-to to grip odd bits normally. I'm hoping it will be useful to hold cutters on the Stent T&C grinder (when it eventually gets finished).

However, I frequently use ER32 chucks (each on a lathe specific back-plate) in preference to my 3/4 jaw chucks and they can hold any length of stock that my 3/4 jaw will manage up to 20mm. Maybe, I should add that I have three lathes operational at the moment and they all have different mandrel tapers. I have managed to move work between them (using these ER collet chucks) on occasion – basically when I managed to screw up my machining sequences and needed to 'tweek' something without messing up my current settings/set-up.

However – being able to hold longer material is extremely useful because many work holding situations are made much easier when the 'work piece' is still attached to the parent material. Much less material gets wasted when you are able to simply part-off as required, rather than cutting material into 'work' lengths plus a bit to hang onto – which results in a box of (often unusable) short ends. These savings can mount up over time!. A back-plate chuck can also be moved to another lathe by simply changing the back-plate (not so easy if the taper is different) and I've done this at least once..

Of course , if you have both a lathe and mill with the same MT taper (as I think you do Martyn) then the advantage will clearly move back towards getting the MT type ER chuck – and you may never need anything else.

However, based on my own experience, I think that once you have used ER collets, you will discover increasing uses for them and you will find your ER holding 'systems' will expand over time.

Regards,

IanT

 

Edited By IanT on 13/08/2015 10:45:43

[martyn nutlandParticipant @martynnutland79495]

Ian

Very interesting and helpful.

As you probably know from my other posts most of the stuff I do is for the Austin Sevens I'm building. The biggest ER collet I have is 20mm which is the maximum recommended end mill capacity of my 'mill' and is as big as I would want to go given the inherent limitations of the machine. Fortunately the diameter of the things I make is almost always under 20mm (brake pivot posts for example) and they are usually quite short, rarely longer than about three or four inches so the collet chuck on the lathe suits. Above that though I would probably have to go to a scroll chuck.

So I take on board all the very helpful points you make. Thank you.

Martyn

[IanTParticipant @iant]

Thank you Martyn, I'm pleased you found it helpful.

As an aside – I often wonder (usually after posting something) if it's that obvious what kind of environment (or context?) the person who is responding normally works in?

For instance – all of my work is very much of a hobbyist nature and tends to be at the smaller scale end of things. I'm sure this is reflected in my views about the utility of various ER chucking systems for instance.

Others here may be simply shrugging to themselves and thinking how much better their R8 tapers and 5C collets are.

Clearly any solutions (or opinions) put forward must be heavily influenced by (and reflect) the personal experience & actual practice of the Poster. Others may have very different opinions to mine – having either worked (or still be working) in Industry or perhaps they are engaged and active on much bigger stuff than me?

I must admit, it's not always obvious to me (when reading some threads here) if the responders 'context' is that clear. It's less of a problem elsewhere (e.g. other forums) because the subject matter often helps to define the general scale of things (and the tooling being used)

Regards,

IanT

[VicParticipant @vic]

There are lots of accessories for the ER32 collet system so I wouldn't be without mine. I have both Lathe and Mill chucks, square and hex collet blocks and a spin indexer. ER collets will grip a wider range than 5C so it's a no brainer if you're starting out.

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