I have make a little test with 4 dots aligned with A tower, B and C tower. Distance W and S are the same in the stl but not in the print. I have tried diferent values of diagonal root but S always is smaller than W, and all S are equal (more or less 38.20mm) and all W are equal (more or less 40.80). I expect that W and S will be 40mm. How can fix this problem?
Here is the stl I use: https://www.dropbox.com/s/2vwjbo387cmk5qa/DeltaCalibration%20v15.stl?dl=0
Update: I have replaced the steper motor in tower B but same result.