wrote:
Hi,

Advice needed. I'm converting a drill press to CNC. Need to bore the
pinion shaft associated with the rack and pinion head feed setup.
Picture of the shaft with gear is attached;

http://i.pbase.com/u26/eldata/large/...G_2138copy.jpg

Gear is threaded on the shaft so it can easily be removed. Normally,
one would just face off the slotted portion to flat then center bore
using center drill, drill then ream. In this case I want the slot (or
what would be left of it) to remain. Shaft is about 1/2" and bore will
be 1/4" so 1/8" of slot will be left on either side.

What would be the best starting procedure in this case seeing that the
tip of the center drill won't be reaching the flat? I'll be pressing a
1/4" shaft in the bored hole that will be coupled to a motor so the
bore has to be fairly accurate.

I'd plug the slot with a bit of steel and soft solder it in place, then
proceed as for a non slotted bar. When finished, soften the solder and
remove the two halves of the plug.
If you don't like the idea of soft solder, use Loctite.

--

Regards, Gary Wooding
(To reply by email, change feet to foot in my address)