Lathe mandrel clamp.

[olderdan]

When using my spring index indent http://www.homemadetools.net/forum/s...4049#post79248
I have noticed that while it is fine for drilling etc it does not provide enough rotational support for heavier milling operations so a means of clamping the spindle is needed, I decided to use my dividing attachment quadrant to keep work and materials to a minimum http://www.homemadetools.net/forum/m...5038#post81061
A scrap piece of aluminium plate was bored to fit a steel bush for the plain end of the mandrel, this bush has an interesting feature in that it is a press fit in the plate but a segment is split part way though the bush to provide clamping force by a screw. This method does not induce any rotational bias when clamped as a normal split clamp might do as it places the pressure though the centre line of a shaft, it it also does not harm the surface. A light hand tighten will securely lock a shaft and it is useful when there is not enough material to put a decent size brass pad under a bolt.
Used recently for milling a hex from round stock for some special cylinder head nuts.