ER Collet

[Piero FranchiParticipant @pierofranchi37209]

Hi There

I would like to buy a set of collets for both my Myford super seven and also to use on my tom senior

am I right in thinking ER32 suits the Myford best???

I dont own any collets at present, So I would like a size that suits both mill and lathe

Also any advise on the collet holder for both lathe and mill would not go a miss.

I am not in a rush to buy, so a far easten flea bay purchase is not ruled out

[Piero FranchiParticipant @pierofranchi37209]

[JohnFParticipant @johnf59703]

Hi Piero, I have ER35 on my Super 7 and find them ideal, mine came from RDG and the chuck was a dedicated Myford one by HBM but I don't think they do those now. Have to say it's very accurate.

Most chucks for lathes are now on the backplate principle so you would need two chucks to use the collets on your mill as well. You could use a morse taper chuck on both with a draw bolt on the lathe as well but you then are limited to short length work pieces. If it was me I would use two chucks.

John

[Bill PudneyParticipant @billpudney37759]

If it was up to me I would get a set of collets and a collet chuck (if appropriate for your machines) or two from CTC direct. Over time I have bought a lot of their stuff, including ER32 collets and collet chucks from them and have never been disappointed. I use ER32 collets on both my C3 mini lathe and X2 mill. Probably shouldn't mention those two machines in the same post as a Myford and a Tom Senior!!

No idea about what chuck fittings would be appropriate for your SS7 and Tom Senior though. All I would think is that you would want a chuck on the lathe that permits bar stock to go right through, i.e. not a chuck secured by a drawbar, whereas the chuck for the mill should be secured by a drawbar.

Google CTC Hong Kong and have a look……..

Best of luck.

cheers

Bill

[Piero FranchiParticipant @pierofranchi37209]

Thanks for the responces guys

My Tom Senior has a ISO INT30 taper with a 1/2 draw bar,

I can find this in a chuck form, but NOT sold as a set to inc collets

I do prefure the lathe chuck and backplate idea as you can keep it all true

Ps, sorry for spelling, was born dyslexic

[Roderick JenkinsParticipant @roderickjenkins93242]

I use ER 25 on my S7 and Sharp mill. I think there are 2 things to bear in mind: First is the size range, 25 goes smaller than 32 but 32 goes larger than 25 – which are you most likely to use? The second point is the diameter of the closing nut, which can get in the way when milling close to holding fixtures on the mill – obviously the 25 is smaller but càn still be an issue. I never use an end milling cutter larger than 1/2" anyway so 25 is all I need.

HTH,

Rod

[HollowpointParticipant @hollowpoint]

I recently did the same thing. Standardised my Collets. I went for the biggest ER40 size for the simple reason that it can hold up to 30mm. Not particularly useful on the mill but a big bonus on the lathe! I also purchased a Stevenson collet block at the same time so I can now accurately hold a good size of round stock in the mill vise with ease. Ive put my purchase list below because I spent a lot of time finding the best buys so you might find it useful.

 

Er40 lathe collet chuck (arc euro) £48

Boxford backplate (RDG tools) everywhere else was out of stock. £20

Er40 Stevenson's collet block (arc euro) £22

Er40 milling collet chuck (second hand) got lucky. I did find a bison ones on ebay relatively cheap.

Selection of Er40 collets. Swiss made rego-fix (eBay) £7.50 each bargain!

Er40 spanner (eBay) again bargain price. £7

Edited By Hollowpoint on 19/03/2016 09:51:02

[Piero FranchiParticipant @pierofranchi37209]

some grate replys guys thanks for the time and effort

[AjohnwParticipant @ajohnw51620]

I've gone further than Rod. I use ER16 in a 2 morse holder on my miller or ordinary 2 morse collets for similar reasons. I did think about getting a large face cutter on a 2 morse shank but didn't like the look of the tips they use so bought one and will have to make an arbour myself.

I have a boxford collets for the lathe but have been tempted to switch to ER making the holder myself. I have a concern though. It doesn't bother anyone else on here only me. Lathe collets have a relatively short grip length. They do this so that they still grip precisely with only short lengths in them. ER and other multisized collets are really intended to grip lengths which come near to passing all of the way through them. Net result I can't make my mind up about what size to buy. A full ER40 set contains rather a lot of collets most of which I am unlikely to use and they are rather long. ER32 more or less goes up to my lathes spindle size and etc.

I'm reminded of a comment some one passed regarding a full set of 5C collets – hardly ever use some of them so buy sizes as needed.

Just add – I would make the collet holder myself as I would prefer it to screw on the nose rather than use a back plate. As I can use a Myford screw on type on my miller I bought one. While the front of it was very accurate the mounting part at the back was well out of alignment so I sent it back.

John

–

Edited By Ajohnw on 19/03/2016 10:34:21

[Russell EberhardtParticipant @russelleberhardt48058]

You might like to consider making an ER collet chuck for the Myford. It is more compact than the backplate mounted versions and, with the taper socket turned in place, there is little room for error. I made one like that for my Atlas over ten years ago and use it more than the three jaw.

Russell

[Michael BriggsParticipant @michaelbriggs82422]

Some years ago I bought an ER25 collet chuck for my S7 and a Vertex 2MT holder and set of collets, a pleasure to use and very good holding grip. Recently I have purchased an ER40 chuck from Arc to increase capacity, very carefully machined a backplate, the runout is minimal. Have a look at the Stevenson collet blocks sold by Arc, I find them very useful.

[John HaineParticipant @johnhaine32865]

I seem to tick several boxes here! I use ER40 collets on my S7 using a screw on chuck bought from the old Myford, to hold sizes larger than the Myford collet set. Whether you use ER32 or 25 either a screw on or backplate mounting chuck is better than a taper mounted one for the lathe as you can hold longer stock and it minimises overhang. I use ER 16 on my little Novamill CNC in an Int30 chuck into the spindle, and R8 on the VMB mill. I would really like a much shorter ER16 chuck to give me more daylight under the Novamill, I'm wondering about making one of those but need to make an Int30 adapter for the lathe first. I also have a cheap parallel shank ER16 chuck so I can use the collets for varying size cutters on the big mill, shortened so it fits with minimal overhang into an R8 collet.

[HollowpointParticipant @hollowpoint]

After machining the backplate for my collet chuck the run-out was 0.01mm I don't know how that compares to what others have achieved but it's plenty accurate for me.

[VicParticipant @vic]

Just a thought but there seem to be more fixtures and fittings that take ER32 collets than any other size and they're also cheaper.

Spinindexer for example has a ER32 adaptor:

**LINK**

[IanTParticipant @iant]

Like most here – I standardised on ER32 in terms of collet chucks, collet blocks, spin-indexer and other fixtures some time ago. I have two ER32 'back-plate' type chucks (one for the Myford S7 and one for the EW) – which enables 'through' work holding. I also have an ER32 (MT2 based) chuck for my mills, although if I have a threaded tool that's the right size, I still tend to use the Clarkson Auto in preference to ER (more through habit though).

I also have an ER16 Taig milling head, so for 'smaller' collet applications, I've now also settled on ER16 (rather than ER11) as my 'alternate' collet size and have spindles, shanks & fixtures that use ER16 collets – generally where size (or work access) might be a problem with the larger ER32 collets.

So to answer the question – a back-plate mounted ER32 collet chuck is a good choice for the Myford S7 in my experience and the ER collets will find many uses in other ER devices over time.

Regards,

IanT

[Roderick JenkinsParticipant @roderickjenkins93242]

It is worth bearing in mind that you can't pass anything bigger than 15mm down the S7 spindle. ARC's set of ER25 collets has a better range of .5mm sized steps at the bottom end than the 32- closing 1mm step ER collets down to the bottom end of their range in the smaller sizes can be difficult and upset the concentricity.

These are the sort of thoughts that went through my mind when purchasing but it really depends on what you use the machines for, I tend to make stationary engines in the smaller sizes so ER25 suits me. You're mill is also bigger than mine. If you have a lot of imperial endmills it may be worthwhile considering purchasing 1/4", 3/8" and 1/2" collets as well, if only for convenience – they nip up easily by hand so you don't need 3 hands to fit a cutter.

I mentioned the nut issue above. My solution when this is a problem is to use parallel shank ER11 collet held in a 12mm ER25 collet – I have a set of ER11 collets for use in my milling spindle on the lathe. I don't think there is a right answer to your conundrum, I reckon any size will be satisfactory – they all have their pros and cons.

+1 for the Stevenson collet block by the way

Rod

[AjohnwParticipant @ajohnw51620]

I reckon ER16 is worth having for smaller sizes. It covers up to 3/8" dia all on it's own and parallel shank holders are available for use as extensions if needed. I also have a full set of ER25's but find I don't use them very often. Main use is in collet blocks.

If I ever do buy larger sizes it will be a limited range of ER40's loosely based round the milling cutter only sets.

On the collet holder making link it's always interesting to see how others do it. I would turn up a piece of bar that is a bit of a push fit into one of the collets and set the compound up initially using this. I would also add a thread to the end to allow it to be held firmly in place for later use as a taper guage. I'd then use blue to check the taper and bring out the dti again to allow tiny adjustments to the compound slide to be made. It's just a case of zeroing the dti on the end of the slide, unlocking it and the precise amount it's moved can be seen. Comes from training. We had to turn up a morse taper to a gauge with blue and later make a reducer sleeve. Having struggled for 1/4 hour trying to adjust the slide I went to the stores and got a dti and finished the job this way in no time at all really. As there was 8 of us doing the same job everybody quickly copied me and nobody had any problems at all getting it right. The other obvious trick is to deliberately have too long a length of material. It can always be trimmed to length once the taper is right.

John

–

Edited By Ajohnw on 19/03/2016 13:22:47

[VicParticipant @vic]

I bought a little ER20 chuck for my small wood turning Lathe, not least because the chuck was only £6.96 delivered and I already had a few collets.

[Piero FranchiParticipant @pierofranchi37209]

Most of the work I intend to do on the mill and Super 7 is classic car related

The Super 7 for me is a little on the small side but it will come in handy for screw cutting as it has the screw cutting gearbox,

I am half way through rebuilding the super 7.

If i can side track for one minute

My super 7 does not have a feed to the saddle

can the screw cutting gear box be used as one or is it nor fine enough???

[MuzzerParticipant @muzzer]

Another supplier of 30 taper ER chucks.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Piero Franchi on 19/03/2016 14:23:43:

My super 7 does not have a feed to the saddle

can the screw cutting gear box be used as one or is it nor fine enough???

There is compound gear in the gearbox, retained by a swinging latch, that is reversed for providing fine feed for the saddle. Finest feed is 0.002 inches per revolution, as shown on the legend on top of the gearbox.

Rod

[Piero FranchiParticipant @pierofranchi37209]

I have the early super 7 WITH OUT saddle feed,

I have yet to use it as I stripped it from day one,

the saddle must get feed when you cut screws no ??????

[Piero FranchiParticipant @pierofranchi37209]

[John HaineParticipant @johnhaine32865]

Funny place to post this question. But when you say "without saddle feed" I guess you mean "without power cross feed" (pxf), right? The Super 7 has always had a longitudinal leadscrew for cutting threads and auto-feed, but pxf is optional.

Edited By John Haine on 20/03/2016 12:27:50

[Howard LewisParticipant @howardlewis46836]

ER25 maximum holding size is 16mm, ER32 is 20mm.

An ER collet Chuck for a lathe will be backplate mounted, and so allow material to pass through into the Headstock. As Roderick says, 15mm for Series 7 Myfords, so ER25, (unless you have one of the later 4MT Super Sigmas in which case ER32, possibly ER40)

An ER Collet chuck for a Mill mounts on an arbor, and is intended to hold cutters, and so has no through bore.

ER collets are very useful, they have a range of 1mm, (except in the smaller sizes, such ER11 or 16) so can be used to hold Metric or Imperial sizes.

You can make up your own holders, for specific purposes. (such as drill grinding) They all use the same 16 degree internal taper (Offset the Topslide by 8 degrees to bore the holder after drilling to the maximum size for the collet size that you are using) for the holder, and the thread pitch is 1.5mm for the closing Nut. Thread size seems to be that of the next size up, ER 25 has a 32 x 1.5mm, ER32 has 40 x 1.5mm ,based on what I have seen. I finish by polishing the bore by wrapping emery round a collet, and running the lathe slowly. DON'T press too hard or it will grab and you could injure yourself. Be content to make haste slowly, after all, you are polishing, not roughing out.

I don't bother with making the Closing Nut, too complcated, so just buy from Arc EuroTrade.

HTH

Howard

[Author]

Posts