Have run several circle tests, and they are slightly out of round…
- In the center towards the top, 6" wide x 5 7/8 " high
- In the center towards the bottom, 6" wide x 5 15/16" high
- 30" either side the error narrows to 6" wide x 5 31/32" high
What measurement errors cause this problem?
FWIW, I used the machine to measure top beam length, and the result was 3004.57… used this for the temp sled calibration. When I calibrated using the new sled, I used a steel rule to measure the distance between motors (right side of right motor spindle to right side of left motor spindle, and I got 3009.9, which I used.
For a rotation radius, I used the default 140mm, which I also tried to measure, estimating about 5.5" (about 140mm). with the new sled, positioning the ring onto the board was much easier with the 3 holes as guides. The support brackets needed to be pulled out slightly, so there was tension on those brackets. Mounting the router was mostly an eyeball line-up…
So it is probably not dead on. When I get back to the machine in 10 days or so, I will try flipping the sled over and checking the position via the router bit.