er collet chuck for tom senior

Hello,I would be grateful for advice on my recent purchase of a Tom Senior M1 milling machine. I would like to use my er 25 collets in a suitable mt 2 chuck. Are they okay for milling ?. At the moment it is fitted with a Clarkson autolock which is seized due to not being used for 2 years and am thinking about removing it .Many thanks in advance for any replies.

cheers.

In good condition ER collets are excellent.

John, i have a tom senior fitted with the knuckle head and use the er32 collets in the mt2 chuck, i got them in a set from rdg tools and i am very happy with them. The er32's will obviously hold a larger range of diameters of tool shanks.

I actually gave away a Clarkson Autolock Collet; everything is now ER series.

I do have a drill chuck on a parallel arbor, so I can insert it into an ER collet in the headstock.

As a backup for loss of vertical, I do have some MT2 collets that fit into the MT2 spindle; I can't actually remember ever using them - but they are there as backup, "just in case" !

I think ER collets are brilliant...

John, as above, ER collets are ok for milling, I use them myself on a much bigger machine with no issues, however the clarkson chuck you have does offer a more positive method of holding cutters as they are screwed into the collets which by design cannot spin in the chuck body. If you are struggling to get a stuck collet out, remove the chuck from the machine, give it a spray with plus gas or similar and knock it out through the drawbar hole with a length of rod.

ER collets were designed for holding cutters. The mistake is not to close them tightly enough allowing the cutter to slip.

In industry they do them up tight - very tight - 70-80 foot-pounds. I suggest using a ball-bearing nut (very cheap) if your chuck doesn't come with one as this reduces the required torque to somewhat less gorilla-like proportions.

Neil

What Neil says, the ball bearing nut is brilliant!

.

However industry which also drives the cutter manufacturers or visa versa have moved off Clarksons which were only mainly relevant in the UK.

Screwed shanks are getting harder to find and in many cases the cutter manufacturer are streamlining their designs to save money and it's very common now to see 4mm and 5mm cutters on 4mm and 5mm plain shanks.

Two sizes that there are no Clarkson collets for.

I parted all my Clarkson stuff out years ago when it was still making silly prices. You can still get more for one at the moment than a brand new ER chuck if that makes sense.

The RDG stuff is, I think, of Chinese manufacture, so if you were to go direct you may be able to get a better deal so it's worth checking. Chinese quality on this sort of item seems pretty good these days.

I have an ER32/MT4 collet chuck I use in my lathe that I got from YSTool on e-bay ( **LINK** ). I have no complaints whatsoever. In my lathe I get a runout that shows up on a dial gauge, at about 0.005mm (less than half a division). The postage price was about the same as the chuck, total coming to about £22/£23 a couple of years ago.

Regards,

Richard

You can buy or make an adapter for a Clarkson chuck that will take Weldon type 6mm FC3 "through away" cutters that are available cheaply in a variety of small sizes. There is also a 10mm adaptor from larger Weldon type utters of various sizes.

I have both a Clarkson chuck and an ER25 chuck for my Tom Senior mill preferring the Clarkson for its superior grip and end location.

You can still buy Clarkson type cutters if you look around a bit. Lightly used second hand ones are often available and are usually UK made. Mr Josey will sharpen them for you at a very reasonable price. This is usually a better bet than buying new Far Eastern plain shank cutters.

thanks for the replies,i have got to a position where i have the spindle with the clarkson collet chuck still in it removed from the head, which still has to be removed but at least is not damaging the head.It my be easier to work on now and will soak it in plus gas. Is it worth putting my propane burner over it .

many thanks john

Have managed to remove collet holder now so its got to be worth replacing top and bottom bearings while the spindle is out. Many thanks for the kind replies.cheers John

Just been told it could well be of Indian Manufacture. Either way, good quality for the price, but may be able to cut out a middle man with E-Bay.

Richard