Lathe collet chuck size

I have a set of ER32 collets, and wish to by a collet chuck holder for my Myford. Arctrade Euro list 4'' and 5" holders and both sizes of backplate to suit a Myford. Does one size have any advantage over another please?

Regards Maurice

Hi Maurice,
The backplates are not just made for the collet chucks so they are made in sizes to be used with 4 and 5 inch 3 or 4 jaw chucks. The collet chucks are made to fit directly on to certain lathes which means they are different diameters. I would choose the smaller one myself. Do you realise that you have to machine the backplate to fit the collet chuck. It would be worth phoning Arc Euro just to confirm that there is no problem with your choice of backplate and collet chuck.

Les.

I am not a Myford owner, although I have read a lot about them and, if I remember correctly, the spindle is bored morse taper no. 2. I'm not quite sure what you mean by your references to holders and backplates, but I would have thought that a straightforward collet chuck secured in said taper would be the easiest (and cheapest!) route. They are available for not a lot of money from CTC TOOLS. (Satisfied customer only.)

John

John the MT holder would prevent you from holding longer lengths

the holders allow a long length to be held

I have a ER40 holder fitted to a backplate for a colchester lathe and very usefull it is

John

The disadvantage with the method you describe is that, by using the No. 2 MT to locate the chuck, you are not then able to accommodate long stock through to mandrel. If instead you go for a collet chuck that obtains is concentrity from the REGISTER then long stock can be accommodated.

( It works for me!)

Regards

Norman

( Whoops - a bit late posting there - I could have saved myself the trouble!) N

Edited By NJH on 18/04/2015 18:21:49

Ian/Norman,

See, I told you I wasn't a Myford owner! I wrongly assumed the collets were going to be used for holding cutters. That's what I use my collets for - but in the mill. I just use a 3 or 4-jaw chuck to hold material in the lathe. Ignore what I said in my earlier post and I'll get back in my box.

John

Thanks for the feed back gents. I do know that the back plate will require machining, the same as some of my other chucks in the dim and distant past. I already have a morse taper holder, but as has been pointed out, long stock cannot be passed through it. My question arose because there is a choice of two sizes that could be fitted to a Myford, and I thought I might be missing some obvious reason for choosing a particular size. Thanks again,

Maurice

I have a set of ER32 collets, with a holder that screws directly onto my ML7 Myford spindle nose.

They were purchased at a Model Engineering Exhibition a few years ago and work well.

Not sure I understand where people are coming from in this thread. For what it's worth, I have both ER32 and ER25 chucks and collets for my Myford (ML7), The chucks simply screw on to the Myford spindle nose thread. No "backplates" are involved and certainly not 4 or 5 inch ones. I believe mine came from Chronos

The Arc ones appear to be mainly directed at the Minilathe market although, I guess you could adapt them with a suitable Myford backplate but it seems a pity to go through two mounting interfaces instead of one.

Incidentally, I don't prefer either one (ER25 or ER32) over the other. I wouldn't want to lose either one. On the mill I again have both sizes but rarely use ER25 and could do without it if I had to.

Because there are 4" and 5" chucks in use on Myfords, the traders offer ER holders in the two sizes so you can match what you have got. If you have no backplate already, chose the size that might also serve for the next chuck you intend buying. Or the size that will also swap to your dividing head, rotary table etc.

Cheers, Tim

I have ER32 chuck & backplate combinations (from Arc) for both my Myford S7 and EW lathes Maurice.

I find them very useful but I would choose the smallest diameter ER32 chuck you can find - as under some circumstances the extra clearance provided might be useful. On the EW I turned the backplate down to match the chuck - I cannot remember offhand what sizes they are - but the smaller the chuck diameter the better I would suggest. I did wonder whether an ER32 chuck would be too large for the 2.5" EW but it's just fine - and I have quite a few ER32 accessories now - it is very useful to standardise on a collet size if you can

IanT

Edited By IanT on 18/04/2015 23:01:29

Hi Maurice,

I have a Myford ML7 and use ER 32 collects quite a lot and my holder is a direct screw onto the nose piece of the ML7 with a very short overhang. The complete unit came from Myford at a cost of just under £100 and in my mind a very worthwhile purchase.

The runout in negligible and allows me to hold very small diameter pieces with ease.

You may want to give them a try and I have no affiliation to Myford apart from being a very satisfied customer and an owner of one of their venerable lathes.

Best regards,

Mike