Two square (octagonal) collet blocks and two 1/2 inch collets. A piece of 1/2 inch Delrin. One cube of mild steel, the same size as the collet blocks. A milling machine. A lathe.
Drill and ream one 1/2 inch hole down the center of the block on the lathe.
On the mill, set up the block, the rod, and the collet blocks on the table with clamps. Drill and ream one hole. Pin it. Rotate and clamp the setup. Drill and ream the other hole. Remove the pin. Done.
Deburr.
Not only have you made your jig but your first part, too. Now the job can be finished to 1000 quantity on a drill press instead of a mill, saving mucho chabo. Oh, yes, you'll need a 3/8 inch "dreamer" so you can go it in one pass, ground for undersize.
Or spec drill rod, which comes slightly oversized, or dowel pins, which come a little more slightly oversized, as the cross members. But since the Delrin is cheap, make the cross members cheap, and just get the dreamer trimmed down a hair.
Is this the knife sharpener again? I charge fifteen cents each time this fixture is used.
Yours,
Doug Goncz, Replikon Research, Seven Corners, VA
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