The carbon fiber axis is .494" OD. So I asked the mills to cut a .497" hole in the center of the bearing block. Still too tight. .500" still too tight. .505" slides on to easily. .502" needed a little polish with 320 sandpaper to press fit. The final step was .5025". This presses on just fine. (And yes, a CNC mill can make a hole .0005" larger with great precision.)
I suspect after a few hundred rotations, the axis will polish a nice smooth bearing in the acetal.
I have now started the easy part; putting four 6-32 holes in each of what were going to be bearing blocks, but are now bearings as well. I just position the .1065" drill bit above the right face and drill both sides in one cut.
Drilled and tapped.
Chuck the axis in the lathe or a drill motor and spin it smooth!
ReplyDeleteIt is already startlingly smooth.
DeleteStroking the bearing on the axis seems to smooth it out well.
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