Replacing a Clarkson 'autolock' chuck with a standard ER collet chuck?

Hi Thanks everyone for all the super advice.
I was very lucky to rescue the milling machine and as you have commented it has cleaned up really nicely. I was hesitant to agree to have it at first as it looked very strange with all the extra pulleys. But then I had not realised it had been sympathetically modified such that it can be configured as either a horizontal or vertical miller.

I have tried the chuck off my Myford 7 lathe and the quill 'nose' thread is indeed the same which opens up many other opportunities

Dave

Yes - it's heartening to see an old machine such as this overhauled and put back into service!

Hi , been following with interest! I have a similar problem to Dave , the quill end on mine has a MT3 and a flat sided socket in which a small clarkson autolock locates. All fine, BUT if i try to fit a MT3 drill with a larger shank it wont lock in the female taper ,as it wont go in to the flat sided socket. A smaller MT3 drill with small shank fits fine! a MT3 jacobs chuck is also a no-no for same reason !!! any ideas please?? Many thanks, Rich

I have a Elliot omnimill with 3 MT horizontal spindle,and er collet chucks foul on the spindle lugs,I found that a er 32 chuck would fit with a minimum of grinding,and it did not break thro, I would now like to fit an ER 40 collet chuk and a quick look with a rule indicates that break through might be very close or would indeed break though, The modified er 32 has worked well for a couple of years.