Small MT2 Tailstock Chuck for ML7

Sorry Michael, I thought you suggested a method of using a hollow MT2 taper and making some kind of sliding arrangement, or the tailstock mechanism you linked to. You didn't mention a collet?

Jason I think was suggesting a simple tailstock collet to hold the ARC supplied sensitive chuck - thus reducing overhang and weight of having a second chuck to hold the first?

Unless I've misunderstood, these are two completely different concepts in terms of cost and complexity?

Yes an MT2 collet closed by a simple cobbled together draw bar would hold the attachment with minimal overhang.

When I first obtained my 'sensitive' drill chuck - I used it held in an MT2 - 1/2" end-mill holder (the tool itself being secured by a grubscrew) to mount in my S7s tailstock - and it worked fine without a drawbar. It also helped to extend the device over the cross-slide btw. There's enough 'grip' in a well fitting MT2 taper to not mind the sprung drill being moved in & out. My issue with the device was that mine had a lot of slop when extended.

You could buy the device and fit it into a MT2 blank arbor by drilling the arbor to suit the diameter of the sliding part of the chuck mount but that would seem a relatively expensive approach to the problem...

Regards,

IanT

Yep, that combination sounds exactly what I was after.

For the drawbar I expect a rod threaded at one end for the collet, and a hollow stepped brass plug to fit into the other end of the tailstock ram would do. Then make some kind of tommy bar thing to turn it?

The job I have in mind is the 0.25 mm diameter hole in the apex of the aluminium cones I mentioned on another thread. I have some PCB drills, so the ARC key chuck capacity should be OK, although it's a shame it doesn't close further.

I'd put the hole into the faced off bar not try and drill the apex. Turn the taper after drilling.

Yes, I was just describing the end result rather than proposing trying to drill at an apex.

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Just to be clear … What I was suggesting [and the reason behind my using those selective quotations] was to bore a MT blank to accept a free-sliding shaft which accepts watchmaker’s collets. The mechanism shown in the Bergeon example is, to my mind, ‘optional’ … at small diameters, pushing with a fingertip should suffice, and is the most ‘sensitive’ feed mechanism available.

MichaelG.