After reading about Evan’s superb results (see 525 Update) I decided to benchmark my existing MPCNC before building a small stainless 1" version.
[attachment file=47684]
I created an array of 63 0.125" holes on a 2" pitch and inserted a 0.125" dowel pin in each hole. I measured every X and Y dimension and used a spreadsheet to calculate the average and standard deviation. Average X was 0.002" over and average Y was 0.002" under the nominal value as originally calibrated and the standard deviation on both axis was 0.005". I think this is pretty good. When I build the new machine I’ll repeat and see what improvement (if any) I will get.
I also did a little math to determine how square it is without any manual correction and it averaged 0.002" over 2" with a standard deviation of 0.005". I also used a square to check the pin alignment in several spots and again it’s not too bad at all considering I didn’t attempt any manual correction.
