When I had a South Bend "Heavy 10" of 1942 vintage (mine for 45 years) it used 5C collets with a draw bar through the spindle. Jaws for your chuck are going to be hard to find until you can identify the make of chuck and find a supplier. If you do identify the chuck try Rotagrip in Birmingham. It may still be cheaper to buy a new imported chuck. I have been quoted £164 for a set of jaws for my 160mm chuck which is about the same as an imported chuck with integral D 14 camlock mount.

R8 are going to be too big to fit in an MT3 spindle and rather long for an adaptor. As mentioned the standard fit is 3C. But have a think about what sizes you really need. If only a few an MT3to2 adaptor plus MT2 collets are fairly cheap from Arc. You will find it is the scroll in the chuck as much as the jaws that are worn. Regrind to remove bell mouth but it still won't be concentric. Just use shims when needed.

I've just had this idea for holding the jaws firm when regrinding. Take them out and measure the offset of the 'teeth' relative to one another. Make a 'spider' with 3 thin legs to match which you can insert in the middle just beyond the jaw gripping face so it bears against the front tooth. Set screws might do for the legs. You might also push the spider from behind so it cants the jaws outward in the slop of the slide as if gripping a short item in the front of the chuck.

By the way I think Harold Hall has details of how to make new jaws on his website.

Edited By Bazyle on 28/11/2016 20:02:00

Matt,

Jaws come with a chuck as a matched set and are numberred for fitting to a particular slot. Purchasing new jaws may not solve your problem which cauld also be caused by wear in the scroll.

A post about jaw grinding was coverred in a previous post under "New three jaw chuck" (see link below)

Paul.

**LINK**