ER40 for Myford spindle?

[caskwith]

Hi chaps, been a while since I last posted here, life seems to have busier and time seems to have sped up 

Right so I'm looking for an ER40 chuck to fit direct onto my myford spindle nose (standard size thread). Have sent out emails to the usual suspects for engineering supplies and so far from the replies, no luck so I am branching out. Any ideas chaps?

[John Rudd]

How about CTC Tools?

They advertise on EBay that they have ER40 stuff...not sure of the nose adapter......

Why not roll your on?.....

[caskwith]

Thanks, I'll give them a try.

I'd like to avoid making my own if possible, time is a factor here since I can likely (I hope) buy one for a lot less than the time it would take me to make one, and also I would be worried about my own machining skills being up to par to get an accurate result.

[JohnHaine]

Will ER40 fit the standard spindle nose?  I have an ER 40 collet chuck I got from myfords a year or two before they closed down.  I think the largest collet will pass 26 mm, and my lathe is a big bore one with a larger nose.  The standard spindle nose only has a 1 1/8 thread and surely would be too small to take advantage of the bigger collets?  By the way try Collets Direct for the  collets, they gave me a good deal on a set.

[philf]

I've not seen a one piece Myford/ER40 chuck but several companies do an ER40 chuck for backplate mounting (Chester, Myford-RDG, Gloster & probably more) and Myford backplates are easy to come by. The idea being that you machine the backplate in-situ on your Myford to minimise inaccuracy. Having said that there are posts on here of people who have had problems with the accuracy of the two part ones.

A friend of mine bought a one piece ER25 chuck for his ML10 and the run-out was unacceptable - hardly better than his 3-jaw chuck.

I know you don't really want to make one but it's fairly straightforward. Doubleboost did an excellent series of videos showing his build of an ER32 chuck for his Boxford last year.

Phil.

[caskwith]

Will ER40 fit the standard spindle nose?  I have an ER 40 collet chuck I got from myfords a year or two before they closed down.  I think the largest collet will pass 26 mm, and my lathe is a big bore one with a larger nose.  The standard spindle nose only has a 1 1/8 thread and surely would be too small to take advantage of the bigger collets?  By the way try Collets Direct for the  collets, they gave me a good deal on a set.

I don't need to pass stock through the spindle, I only really work with shorter pieces and make do just fine with my 3 jaw so will be no loss with the collets either.
Thanks for the tip on the collets.

[caskwith]

I've not seen a one piece Myford/ER40 chuck but several companies do an ER40 chuck for backplate mounting (Chester, Myford-RDG, Gloster & probably more) and Myford backplates are easy to come by. The idea being that you machine the backplate in-situ on your Myford to minimise inaccuracy. Having said that there are posts on here of people who have had problems with the accuracy of the two part ones.

A friend of mine bought a one piece ER25 chuck for his ML10 and the run-out was unacceptable - hardly better than his 3-jaw chuck.

I know you don't really want to make one but it's fairly straightforward. Doubleboost did an excellent series of videos showing his build of an ER32 chuck for his Boxford last year.

Phil.

Yes I have seen those and they may be my only option but my google fu showed up similar problems to those you mention, they seem to be a bit hit and miss on accuracy and while I know I can turn an accurate back plate, fitting that to a collet chuck that may not be accurately machined could cause my errors to mount to an unacceptable level.

[JohnHaine]

RDG Tools eBay site lists an ER40 collet chuck with mt2 shank.  As the Myford old spindle nose is not really relevant in industry now I think that's the best you will be able to do.  Not very elegant, lots of overhang.

[caskwith]

RDG Tools eBay site lists an ER40 collet chuck with mt2 shank.  As the Myford old spindle nose is not really relevant in industry now I think that's the best you will be able to do.  Not very elegant, lots of overhang.

Yeah I don't really want to go for that option, aside from the overhang I would also lose any spindle capability at all and while I may not need it very often it is always nice to have it there.

[caskwith]

Well CTC got back to me, they don't have any and suggested the following, personally I think that is even trickier than buying the 2 part setup or making my own.

"If you can not source it in other way then I would suggest using one of the larger ER40 chuck (ER40 MT5 or ER40 BT40). You can cut away a portion of the shank, bore it and thread it. They are normally induction hardened to a depth of 0.8-1mm so it is quite do-able if you use a carbide tool bit for the boring operation"

[JohnHaine]

If you think about it no one is going to manufacture an ER40 collet chuck to fit  the small Myford nose thread because the mandrel bore is too small to make use of the collet capacity and few people are likely to buy them.  Actually I think your best best is to buy an ER40 collet closer and the collets, and make the chuck body yourself.  Use a big slug of nice steel, bore through and turn a register/nose thread at one end, turn round and mount on the nose to turn the collet taper and closer thread.  Set the top slide to the collet taper by sliding a collet onto a nominal size ground steel rod and holding it in the 3jaw, then use a dti.  It's relatively easy to make ER collet holders, I did an ER25 one a few years back.

[caskwith]

Yeah you are probably right John but it was worth a shot. I am not sure I trust myself to complete all the steps involved in making my own and I can't really afford to spend that much time on a work project. I guess I will have go for the 2 part method and hope I don't get a dud head.

[caskwith]

Ok I think I have made a decision. I checked and the recess on an ER40 collet is 57mm, actually deeper than the holding recess on my 3 jaw chuck.
So I'm going to be a MT2 chuck with full set of collets, see how I get along with that and if all goes well then I will make a proper ER40 chuck to screw onto my spindle nose. The way I figure it is that most of the cost is in the collets anyway so by doing it this way I get to try it out and if I like it I can still make use of the collets.