On Sat, 18 Dec 2010 14:33:11 -0700, "Bob La Londe" wrote:



I don't understand the hex and pins bit. I figured I would just take a
piece of 1/4 rod and thread both ends. Then thread a 1/4 x 3/8 bushing on
one end, and thread a hand knob on the other end. Use red Loctite and a
butted tight shoulder on the bushing to keep it from coming off. The mill
does not have a motor reversing circuit.



I think the hex and pins bit was a way to avoid the threading and to give an
end that could be tightened with a wrench. Good idea for R8 or NMTB tapers.
Overkill for Morse tapers.

If the hole in the spindle is big enough that the drawbar could be off centre,
then instead of making the end of the hand knob tapered, make it with a pilot
that is a good fit in the bore. You can still have a flat face for the thrust,
but you get centring as well :-)


Mark Rand
RTFM