ER collets on Myford

I know I can get MT2 - ER245 converters, but the use of a drawbar seems superfluous when I've got the Myford threaded spindle nose.
Does anyone make a Myford / ER25 or ER32 converter, or would it be feasible to make one myself ?
Can someone point me to a full set of ER dimensions ?
-adrian
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Adrian Godwin wrote:

There is one that comes up fairly regularly on e-bay, on there now as item no. 330042431615.
For fairly detailed dimensions go here to download the PDF file, the detail yo want is on page 2 http://www.rego-fix.ch/pdf/Katalog_English/Kapitel_13/Kapitel-13_2004_e.pdf
I have one of these on the project list to make for my Myford, as I already have the ER32 collets for the mill, and a nice handy length of EN19 to make it from. You can buy the collet nut from a host of sites, J&L is the first that spings to mind.
Peter
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Adrian Godwin wrote:

Im sure ive seen one on the chronos site somewhere. but iirc it was a thing which threaded onto the myford nose then had a closing nut on it.
Dave
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Adrian Godwin wrote:

Adrian
Nigel Bennett had a design for an ER32 Collet Chuck for Myford 7 series lathes published in the October 2003 issue of Engineering in Miniature. I made two, one for my S7 and one adapted for my Boxford, they both work exceptionally well. The only cost to me as I already had the ER32 collets was for a piece of suitable 60mm bar which I think cost about 15 as was enough to make three complete chucks. They are unhardened but have done a lot of work in the last two years and show no signs of wear. Making them was not too difficult and I found it an interesting exercise. I built them on the lathes they were to be used on without difficulty. Believe me if I can make them anyone can. The advantage of this type of mounting is as you say that you do not need the drawbar and can therefore use the system to hold through bars as long as they will pass through the Myford spindle.
They have been so useful that I also wanted one for my Warco BH600 but this time instead of making one (too busy) I bought a backplate mounted ER32 version from ArcEuroTrade (40ish) at the recent exhibition. Very well made it was the work of a few minutes to turn the register on a suitable backplate to mount it. It doesn't appear to be any less accurate than the direct spindle mount one as long as you turn the register on the lathe it will be used on. This one also has the advantage of beign fully hardened.
I use mine a good deal and can fully recommend them. Adrian let me know if you need a copy of the article and I will send you one.
Best regards
Keith
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jontom snipped-for-privacy@hotmail.com wrote:

Thanks, Keith - that would be very welcome. I'll email you my details and reimburse any costs.
Thanks, too, to all the others who responded. The one on ebay is Chronos, but Norman's comments are very illuminating : it seems odd that these cost twice as much as a 2MT converter despite being no more complicated and apparently being pretty poor accuracy. Making one myself seems worth the effort.
I do already have the Myford set but only for imperial. Additional collets are expensive, limited in range, and hard to find secondhand. And the box is almost full already :-). If I'm going to build a metric set it seems more sensible to use an ER range.
-adrian
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Me too.
--
Charles Lamont

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I got a straight shank ER 25 collet adapter of ebay and it's more o
less permanantely mounted in the 6" four jaw chuck on my Myford.Th chuck's one that's threaded for the Myford spindle.
Alla
-- Allan Waterfal ----------------------------------------------------------------------- Allan Waterfall's Profile: http://www.rcgroups.com/forums/member.php?uR67 View this thread: http://www.rcgroups.com/forums/showthread.php?tX790
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Hi Keith
Regarding the postings below from the news group
uk.rec.models.engineering
I too own a set of ER32 collets for my Warco VMC and would love to use them on my Myford S7 . Would it be possible for me to get a copy of the article from you too
Regards Don

jontom snipped-for-privacy@hotmail.com wrote:

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Both Chronos and Arrand do an ER25 chuck which screws onto the Myford nosepiece. There are also, as others have pointed out, versions which go on a backplate.
I bought a Chronos screw-on one about 12 months ago and found it had runout of over 0.007". I traded it for a new one and got about 0.005". In the end I returned it and bought the Arrand one which was a lot more expensive but still had an unacceptable runout.
I took a bit of silver steel bar which fitted tightly in an ER25 collet, centre drilled both ends, mounted it bewteen centres with the collet on it and used a dial gauge on the tool post to set the topslide over to the correct angle. Screwed the Arrand chuck tightly onto the Myford spindle then used a new carbide tip in my stiffest boring tool to take a very light skim along the cone in the chuck body. Now gives runout of typically less than 0.001" across all of the collets in the ER25 set - which was an el-cheapo from RDG. In te end, after a lot of hassle I'm reasonably pleased, though I don't think its as acurate as a "proper" Myford collect chuck - but then again it didn't cost as much.
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On Wed, 25 Oct 2006 13:17:22 +0100, "Norman Billingham"

Chronos (I assume it's an own brand item) have also started doing them to fit a Boxford. 125 quid though! it says "TOP QUALITY BRAND NEW BRITISH PRODUCT" part number BFC1.
No connection except being a slightly pi$$ed off customer that just got stung for an extra 20% on a lathe chuck from them by clicking the wrong link.
Do Arrand have a website/online presence?
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Adrian Godwin wrote:

I bought my ER32 collet chuck from Warco, it's in their catalogue at <http://www.warco.co.uk/productimages/documents/Pg42.pdf . If you can turn up a backplate then this will do you fine (or at least mine has been OK).
Hth,
--
Boo

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On Wed, 25 Oct 2006 12:22:07 +0100, Adrian Godwin
Adrian,

I've gone through something similar to Norman - having bought a Chronos ER25 Myford holder and getting runout of several thou. Chronos did replace it, but the runout was still one or two thou which I thought unacceptable. I could get about the same runout on my Burnerd three jaw. The holder was not a tight fit on the spindle register and I reckoned that this was the reason for the runout. I got my spindle register checked and it was spot on.
By this time I was corresponding with Norman and knew about his experiences with the Arrand adaptor, so I didn't go down that road. Lots of work (the type that keeps a roof over my head :-) ) then got in the way and I only got back round to looking at the problem a few months ago. At the Bristol exhibition , I noted that Warco had a. ER25 backplate mounting holder, so I got one of them and a threaded backplate off the Myford stand and I've now got a holder which has about half thou runout, and I think I can get it closer. I actually screwed up on cutting the register and went a thou too deep so there is a small amount of play which I'm playing around with at the moment to get the minimum of runout. The overhang of the backplate setup is about the same as the nose mounting one.
BTW, I have a set of Myford 2MT collets and they are not all that accurate, with runouts of over a thou in most of them, and one has a runout of about five thou.
Jim.
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wrote:

Their is a note in this month MEW about Myfords having trouble sourcing a supply of affordable and decent collets. Apparently it's taken them 2 years to find one. 18 month of that was waiting for the phone to be reconnected..
I have also heard problems with the screw on Myford nose type but you have no control over what the chuck was held on for the ER taper to be fitted.
At least if you go the backplate method as people have mentioned you should be able to get it dead nuts. Another plus is that the cost of a semi machined backplate, i.e. the thread done will ensure you have the minimum of run out.
You also get the chance to swop this between machines if needed or you change machines. -- Regards,
John Stevenson Nottingham, England.
Visit the new Model Engineering adverts page at:- http://www.homeworkshop.org.uk /
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John Stevenson wrote:

John, having heard of these problems from several suppliers and experiencing a poor backplate myself, I took the one I bought from Ketan and mounted it as Norman said between centres with a bit of 16mm silver steel. To be honest I couldn't measure any runnout on the backplate register recess and it has proven very accurate now it is mounted. I suppose I will need to get a better dial indicator than the Starret I currently have to get it "dead nuts" though.
I should have had more faith really but I certainly do now and as you say when (not if?) I change lathes again it's just the backplate that will need replacing.
Best regards
Keith
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For those wishing to make their own adapter there was a design published in MEW. The collet nut which is probably the most time consuming part to make is also avaliable seperately, Axminster sell them for less than ten pounds. jontom snipped-for-privacy@hotmail.com wrote:

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On Wed, 25 Oct 2006 16:46:36 GMT, John Stevenson
John,

Most of my 2MT collets were bought in ones and twos during the 70s. There used to be a very good Myford stockist in Edinburgh and every time I visited the city, I bought a collet :-) But I always expected them to be true and never checked them until someone raised a question about their accuracy on another mailing list. When I checked them, I found the runouts that I mentioned earlier. I checked them all over for obvious problems like rough corners on the slots and muck on the tapers and bores but found nothing - and the taper in the spindle was OK. That's when I went looking for alternative collets like the ER25.

With the second one that Chronos sent me, it looked as though the problem was probably eccentricity of the whole body, possibly caused by the item taking up an off centre position due to the loose-ish fit on the register. I clocked along the body and the piece in the collet and the runout was the same. I think if I could have got a good fit on the register then the runout would have all but gone. There was just over a half thou clearance on the register - i.e. it was a mild rattling fit.
Jim.
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Jim Guthrie wrote:

Jim, I had some problems with backplates having excessive clearance on the register although it was a fair bit more than yours, at least .002". While the register was that loose the thread was tight and I couldn't get any consistency at all. As a last ditch "fix" (bodge) I cleared the thread so that the backplate fitted on the vertical face and the thread didn't influence the position. At least it took up a consistent position and as you say with the backplate it is possible to move it on the larger register. Even now it isn't as good as your half thou but it works OK with a four jaw on. Annoying though when these part machined bits don't fit as I think they should. During the thought process I did consider trying to nickel plate the internal register with one of those cheap plating kits, although depositing several thou might have been a problem if you only need a couple of tenths it might be OK. Not sure how even it would coat though or how long it would last in use. I suppose if someone comes up with a cheap, reliable easy to use, cold working "steel putting on" tool there is a fortune out there to be had. The other idea is to bore it out and shrink fit a ring in and then re-bore concentric and to the correct size, again depends if the internal register is hardened.
Not suggestions really Jim, just thinking out loud. For me this was one of the disadvantages of retiring; a few years ago I would have given it to the lads who would have ground, hard plated and re-ground it for me all for a few quid in the tea swindle. Funny how we could never find the capacity to "fit in" another "bl****dy jet engine but there was always a bit of time for an interesting homer.
Best regards
Keith
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On 26 Oct 2006 14:36:54 -0700, jontom snipped-for-privacy@hotmail.com wrote:
Keith,

I also had some thoughts about plating the back of the adaptor to get a better fit, but I wasn't exactly sure how durable the plating would be.

I also thought about doing something like that but I wasn't too confident that I could do that with the accuracy required with the equipment I've got. But now that I've got a satifactory alternative, I might have a go and see what transpires :-)
Jim.
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Jim Guthrie wrote:

Jim, a man after my own heart I see, I always have to have a go at fixing things as well. I never throw anything out until I've knackered it personally, at least twice.
If as Norm said you hold it using one of the larger collets on a bar between centres, even turn the bar to size yourself, it should (famous last words) be concentric. I'm very much a novice at actually doing things myself and so for me getting better than half a thou would still be a bit daunting. Got to be worth a go though.
Best regards
Keith
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On Wed, 25 Oct 2006 12:22:07 +0100, Adrian Godwin

Warco sell a backplate fitting ER25 collet chuck that sells for a remarkably reasonable price - I have one fitted to my Myford using a Myford backplate from Arc Eurotrade.
Regards, Tony
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