I have been looking for 3/4" straight shank tooling adaptors to suit ER16 and ER20 collets or Jacobs taper mounts for JT2S and JT33 or JT6. There are plenty of ER collet chucks available but unfortunately they are all in 20mm shank diameters. The only ones available in 3/4" are from the USA. Anyone know of a supplier in the UK able to source these shank sizes from.

The reason for the 3/4" shank is they are for a capstan turret and 3/4" is the small standard size for capstans. 1" and 1 1/4" being the larger sizes. I need 4 of these and may have to revert to making my own!

Martin

I had considered that route Michael – but four shanks at £10 a throw to get ground (uness I do it myself with the toolpost grinder) is about half the cost of the 4 shanks! Why can't suppliers supply parts that are needed? Obviously there is a market in the US for these parts and they must be having them made in far off lands at the prices they are charging (about half the price of the parts here). What's the difference between supplying 20mm shanks and 3/4" shanks? Apart from 0.95mm!

I guess there is no call these days for capstan tooling as the imported lathes do not appear to offer them as accessories.

Hi Jason,

I could and I probably have some suitable sleeves from my 'big' boring and facing head. The reason I need ER 16 or JT2S is I need to centre drill, drill through [7mm], then I need either a JT33 or JT6 to mount a suitable chuck or a couple of ER20 chucks to mount up and drill 27/64th, then clearance drill 1/2". This accounts for 4 stations on the 6 station turret capstan. The last 2 stations are taken up by an internal recess grooving tool and a chamfer tool.

I think the route I'm going to take is to make up the JT's I need onto some 3/4" bar.

DC3,

Unusually, I missed the MSC site which is normally my first port of call. Thanks for reminding me, 2 x ER16's on order at the 'Sale' price; now, as there appears to be nothing other than ER16 in 3/4" shanks I'm going to make a couple of 3/4" x JT6 taper and JT33 taper shanks to fit my chucks to.

David, and others,

Yes, could do, but I worry the 1/2 shank will slip, I drive the capstan hard!

Jason,

140 off – definitely a Capstan job, then onto the other lathe, set up in back gear for tapping. They are special 'extended nuts' for an ambulance conversion for mountain rescue to Polaris 6 x 6 off roaders. 

Thanks for the responses,

Martin

Edited By Oily Rag on 30/03/2021 19:21:09