Twist Lock Caps and Right Angle Machining

Hello,

I want to make twist lock endcaps for a 1.88 inch OD, 8 inch long,
silver annodized aluminum tube. The endcaps might be brass or delrin,
just for an attractive contrast with the tube.

The kaleidoscope optics stacked inside the tube are spring loaded so the
natural length is a about 1/8 inch longer than the tube length and the
compressed length fits comfortably within the tube.

I would like to carve a small track in the wall of a 1.9 inch diameter,
3/8 inch deep, pocket. The track is a little wider than a dowel pin that
travels in the track. Dowel pin diameter is not important but in the
range of 1/16 inch to 1/8 inch diamter would be best.

A right angle drill like a dentist uses comes to mind.

I have in mind 2 or more dowel pins protruding outward from the ends of
a long tube. Drilling and press fitting would be straight forward.

The endcaps would twist lock onto the tube ends like a BNC connector or
a child-proof pill bottle. I prefer that the track not effect the
outside appearance of the endcap so I really don't want to cut from the
outside if I can avoid that.

I am also looking at things that cut sideways like threadmills, keyway,
and Tslot cutters. I have done threading with a threadmill but this is a
very skinny track so not my first choice. A keyway or Tslot cutter might
work if I can find the right one.

I could also mill the track on the outside of the tube and use dowel
pins on the inside of the endcaps. But I would still need a right angle
drill to make the dowel pin holes from the inside of the pocket.
Drilling through and press fitting from the outside would certainly work
but, as above, I prefer that the pins not show.

Or maybe I can jazz up the exposed pins so that they are attractive.
Perhaps screw them in then cover with fancy cap nuts.

Anyway, machining from the outside presents no challenge so I would like
to explore methods of drilling or milling from inside a pocket.

I have a Sherline 4400 manual lathe and a Sherline 5410 (metric 5400)
CNC mill and a short 1/2 inch drill press. I have access to more
complete shops if need be.

Comments and suggestions?

Tom Hubin
thubin@...