Which Collet Chuck?

I have just treated myself to a Warco 180 as a retirement present, and am considering getting a collet chuck, but am unsure whether a flange-mounted one or a MT3 mount would be better. Any opinions would be gratefully received.

Thanks,

Colin

Colin,

the flange mount one has the advantage of being able to accept longer stock via the through-hole. Obviously restricted by the diameter of the spindle bore. The morse taper type will only take a limited depth of material. They're not that expensive so treat yourself and get both!

Enjoy your new purchase and retirement,

John

I think also if runout is a thing that worries you, the MT3 chuck is better. The flange mounted one's will tend to have more runout due to the spigot clearance adding to the eccentricity of the collet holder to the spindle axis.

With my 'Arc quality' MT3 collet chucks find I can turn one end of small parts, then turn the part around and machine the other end, with almost no perceptible step from the two operations.

Gerry

Personally I don't have that lathe, but use a Myford S7 and a Warco GH1330
I have and use both MT and screw-on/backplate ER25 chucks as well as a larger 5C setup on the bigger lathe.

The ER25 on a separate backplate is more rigid than my MT2 one, and it also allows fine tuning of concentricity, which the one piece MT mount one doesn't. As mentioned by John above, the backplate type has a through hole, which allows for longer stock as well as just holding short workpieces and cutters.
To my mind, the MT variety best suits a mill as a cutter chuck, and the backplate one suits a lathe.

I note that Warco supply an ER25 chuck for your lathe, but the spindle bore is listed as 21mm.
To that end, I'd consider getting an ER32 backplate setup, as the ER25 is limited to 16mm max through size.

I'm not sure how the chuck fits your lathe, screw-on or bolt-on, but if it's screw on, I'd still prefer a two piece ER/backplate setup, for the concentricity reasons I mentioned earlier.

Bill

I use ER32-3MT collet chucks on my mill, lathe and rotary table. As they all have a 3MT taper, I am able to take the job from one machine to the other without removing it from the collet. The chucks are not that expensive and I often need to use 2 at the same time. One to hold the job in the RT and a second to hold cutters in the mill. The majority of my jobs are short and do not need to extend into the lathe spindle. I use a 4-jaw chuck for parts that have to extend into the spindle.

I like my 5C on it's backplate. One handed (chuck key) operation, able to hold short lengths, smooth nose if you need to get your fingers near it. No problem for workholding on the mill when the work needs the same dia collet as the cutter.

May need a few more collets due to them being size specific than going down the ER route

Thank you for the replies, I really appreciate it. Hmmm, the ability to pass long stock through the spindle hole may be important, but the extra accuracy of the MT would be useful too. I will have to think about it.....

On the other hand if your MT chuck turns out to be off you can't easily do much about it, a flange mount on a backplate can be adjusted to run true and then locked in position.

Flange mount every day of the week.

Tony

The R / 3MT is mostly used in nthe Mill.

For the Lathe, i fabricatedn a backplate for a flange mounted ER collet chuck. Coated the backplate with Loctite mand clocked the internal taper untilo minimal runout.

Some years later, bought a casting and machined that as a one piece backplate for the collet chuck. But found that the chuck would not separate from the fabricated backplate, so it is still in use, with the casting stored somewhere!

So long ago, can't remember where I put it.

But both have their uses, so if the budget will stretch, buy both. If not, then the backplate type has be the front runner.

Howard

I fully agree with Jason regarding the flange mount in conjunction with a backplate having potential adjustability for radial runout, and have the through hole for longer work. We have one in er25 to utilise the collets used on the mills. For a lathe, however, the er32 would be a better choice as it can hold up to 20mm stock.

**LINK**

Edited By old mart on 29/04/2022 16:53:32

I remember now why I did not buy a collet chuck a couple of years ago, it was because the reviews of the cheap ones were so bad that I did not think that it was worth it. Has the accuracy improved now or are the cheap ones still wildly inaccurate?

Some of the cheap collets leave a lot to be desired in the accuracy department. Collets from an industrial supplier such as APT are available in different grades. I have an er25 R8 collet holder that has a runout of 0.003" tir in the internal taper, there is no way I can easily fix that, so it is not used.

**LINK**

Reports of wild inaccuracy may have been exaggerated at the time! If you're unlucky and buy an unacceptably bad dud collet chuck from a reputable UK supplier they will replace it. But bear in mind hobby tooling is made down to price and buy an industrial chuck if you really need guaranteed accuracy. Expect to pay serious money for it and make sure your pacemaker has a new battery before asking.

MT vs backplate: backplate wins in my opinion. The advantage of MT is that the chuck can be plugged in and out quickly, which matters little in my workshop. A major disadavantage of MT on hobby kit, whether a sloppy new hobby lathe or a bashed about oldster, is there's no adjustment. If there's run-out, you're stuck with it.

Although a backplate takes longer to install they can be adjusted to almost entirely eliminate runout. The method is to mount the backplate with the bolts hand tight and put a ground rod in a collet, Then turn the lathe by hand and measure the run-out with a dial-indicator. Any run-out can be tuned out by tapping the backplate gently sideways with a rubber mallet. Tighten the bolts when the dial-indicator confirms it's good enough.

Collets are excellent for maintaining concentrity when working extensively with round rods. But they're not as convenient as a 3-jaw chuck for general purpose work, or as good at holding odd shapes as a 4-jaw. (And 4-jaws can be tuned with a dial-indicator too.)

For what it's worth, roughly 80% of my turning is done in a 3-jaw. I use a 4-jaw for almost everything else, and the collet chuck only comes out for special occasions - lots of smallish round rods going in and out of the chuck repeatedly. For me, that's usually when making something delicate that frequently swaps between mill and lathe. When I need them, collets are wonderful, but I don't use them much. Depends on the workshop - they score high for clockmaking and similar.

Dave

Should point out that the tapping true method SOD describes should be carried out after turning the register on the face plate a bit smaller so the chucks body can move about otherwise you will just be banging away at a chuck that has no way of moving.

Saw this video earlier today which shows how to make what would seem to be the best of both worlds regarding backplate vs Morse taper. Basically a threaded "nose" which takes the collet. Only hard part for me would seem to be machining the taper for the collet.

Quite fancy having a go at making one myself one day - it's on the list...

Rob

Links to https://www.youtube.com/watch?v=-MWQkdjv-aM

I have a WM180 and an ER32 backplate-mounted collet holder. I have no problems with lack of registration, you can take the assembly off, turn it around, put it back on, and the work remains true. The mating spigot seems very accurately made with absolutely minimal clearance (I recently read that this mounting method is an ISO specification).

The chuck/backplate came from ARC, so no connection between the manufacturers of lathe and chuck, except that they both apparently took note of that ISO spec.

I use it a lot, and I think a MT variety without a through hole would not be nearly as useful.

re. collet chuck accuracy - I do have an ER20 2MT holder (for the mill) which displays considerable run-out - it was a very cheap ebay purchase. I replaced it with one from ARC which is far better (I can't remember the figures off hand, but I think the cheapo one was at least 10x worse).

Thanks Andy, that is very good to know.

A two piece has to be the way to go especially from the No 2 MT size downwards. The Clarkson 2mt collet chuck has left hand threads on the back of the holder so after tightening the drawbar the Lh threaded nut was screwed up to the machine spindle increasing rigidity. I have a small mill no1 mt with a threaded nose so I have a nut on the spindle and bring that down to the collet chuck, same thing in revers to Clarkson. But all this is not needed if you go the two piece route.

I have an unwanted Clarkson Autolock (S type collets) on a MT4 taper. If you want it you can have it but you would have to machine the taper down to suit. It has four imperial collets plus a spare nut and extra imperial collets. The draw bar thread is 1/2". Message me if you are interested. Only want post and packing refunded for it.

Martin C