Fun With Fiber

I needed four 1.00" x 1.00" squares to act as dust caps and bearing holders in the polar and declination axes.  It was more work than I had hoped, but by the time I was done, I had four squares that exactly fit into the 1.03" x 1.06" tubes.  They press in tight enough so they have to be pressed out from the far end.  The next step is to drill .875" diameter holes in the center of each.  I have a Forstner bit that size but I want a tight fit, and they are HSS and likely will lose sharpness cutting carbon fiber.  

The solution is to write gCode that cuts the circles with the carbide end mill.  The gCode for this is theoretically simple, but I have never done this successfully, so there is some more to learn and experiment on acetal.