Thread: 260 spindle collets, 4MT or collet chuck

Hi guys,

Finally finding time to get back to playing in the shop and have a few small projects that I would like to hold the material in collets rather than the 3 jaw. I have been searching for a few days and am having a hard time deciding which way to go. The 4MT collet holder is readily available, don't really care if it's ER 20,32 or 40, but have been led to believe a collet chuck is better, but I can't find much in 1.75"x8 TPI. I have a set of 5C collets already if that helps at all.

I would love to hear from someone with more experience than me which way to pursue.

Thanks!

PS it's going on my Hercus 260

Hi Kilohertz,

Nothing wrong with 5C collets, you might have to get or make a draw tube in order to use them. Alternatively make a closer cap on a backplate.

1 3/4x 8 tpi collet chucks are available in ER40, finishing of the ER taper may be required for everything to run true on a particular machine.

Originally Posted by BaronJ

Nothing wrong with 5C collets...

Well, in general - not quite. The drawback with 5C style collets is that they have to be matched to the size of the stock you are using. They certainly work (and I have a few myself), but if you have odd sizes of material, it may not be as good. I use collets that can cope with that variation for that reason.

If you are using stock of a known standard size, perhaps go the 5C route. If there are weird or non-standard sizes, ER might be a better way to go. I have some in a number of the series. The bigger they are, the more they will grip (ER25 max is 16 but ER40 is 30). However, the larger nuts need more grunt to tighten.

You may have to make your own ER collet - either cut the spindle thread and machine to suit or bolt together a backing plate and a collet mounting plate (something like this - https://www.ebay.com.au/itm/29364160...Bk9SR8bSyvftYQ) without the D1-4 mount on the rear

Michael

I will also suggest having a look at this thread as a few options were discussed and Mal had done a few runs of an ER32 collet for the members:

https://metalworkforums.com/f189/t19...r-hercus-260-a

Mal (aka allterrain50 on this forum) runs a website AMH and supplies Hercus parts and perhaps you want to contact him to see if he has anything useful left over that might suit your needs:

https://australianmetalworkinghobbyist.com/

(Kafie, the poster is in Canada; may not have a Hercus)

I don't think 5c will fit up the guts of a 260 will they? If not id use something else otherwise they have heaps of stick out.

Thanks boys,

Appreciate the quick replies. Yes, it's going on a 260, and after reading the threads and pros/cons I think something like this is what I am after. I need the material to go thru the spindle so 4MT is out.

I will try Mal, and maybe Pipeclay as I think this picture is one of his??

Cheers

I spent some time in the shop today doing routine maintenance on the 2 lathes, oiling, cleaning etc. Then I started going thru some of the tooling I have acquired in the last year or so. I came up with a way to use my 5C collets, by my suspicion is this is a no-no. I didn't tighten the chuck, just placed it for the picture. This is in my Cinci 13x48 Hydrashift, the collet holder won't fit in the Hercus. I also found a nice set of what I think is ER16 or 20 collets but no holder for them.

Again, appreciate any guidance you may offer.

Cheers

IMG_4508.jpgIMG_4510.jpgIMG_4509.jpgIMG_4493.jpg

Originally Posted by Kilohertz

I also found a nice set of what I think is ER16 or 20 collets but no holder for them.

Again, appreciate any guidance you may offer.

Cheers

IMG_4493.jpg

What you have there is a complete set of Myford collets with a spindle nose piece and closing tube. Used on the S7 and ML7 lathes.

There is no adapter because the nose piece screws directly onto the Myford ML7 or S7 spindle nose which has a 1-1/8” 12TPI Whitworth 55 deg RH thread.

Here is a video on how these are setup and used: https://youtu.be/2IKisAawbec

They have started to become rare as hens teeth and anyone selling wants a pretty penny for them.

I have been searching for an affordable set for the past 6 months

And there you are on the other side of the world with a set you have no clue about?

Its not funny but it is funny.

Should be okay as long as there is not too much runout in your 3 jaw, it will probably start to get tedious taking your 5C out to loosen the nut often, then you may run the risk of changing the possible runout each time you change your job.

I don't think you need to worry about crushing the collet holder in your Chuck, as long as you don't go overboard on tightening your 3 jaw.

I use these straight shaft collet holders in a 4 jaw chuck, i have 3 sizes and also have an er40 with a 5c shank, the links below are just an example for you to look at, i bought mine from aliexpress so maybe have a bit of a look around yourself.
https://www.ebay.com.au/itm/28460694...Bk9SR86QsNjuYQ

https://www.ebay.com.au/itm/16366728...3ABFBM5PW12O5h

In past when i have posted anything about straight shaft collet holders there has been very little interest, i find that interesing?
Compare the cost of this little collection to a D1-4 collet holder and then consider the range of versatility, a spindle mounted collet holder is just that, straight shaft collet holders can be used on any lathe and also the smaller ones can be held in a collet as in the pic below.
They can be offset in a 4 jaw chuck for machining eccentrics and if the user is capable of using a dial indicator they are as accurate as the spindle mounted collet chucks.
Here is a pic of my collet holders, plus there is a NT40-ER40 in the vertical mill.

Nothing wrong with straight shank or even tapered shank collet holders apart from:
- not having the ability to pass long material through
- having to make a drawbar for taper shanked versions

If I have one lying around then I will definitely use a straight or tapered shank collet holder but if I had to buy it then my preference will be a direct spindle mounted collet chuck/holder.

I know this is a long shot but the 260 used the 4c collets with a closer and draw tube, these are quite rare here in Australia but I bought my 4c collets from a guy in Canada and I am making my own closer as I had the draw tube, from what I understand that set up was used in quite a few US machines and may have more availability over your side of the world. There is a photo of what I am making for myself as well as the draw tube.