Delta calibration object for precise measurements

This is a remix of Klipper FW enhanced delta calibration object.

The main difference is M2 holes in place of pillars. This factors out dimensional inaccuracies of printed pillars, replacing them with heads of M2 bolts. For extra precision, you know.

This object fits nicely in 100mm diameter build area.

Distance between centres of any nearby holes is 45.5mm, or 91mm across the center (scale factor 0.7 for Klipper calibration, it expects distance to be 65mm). Pillar widths will all be the same and equal diameter of bolt heads you use (3.8mm in my case).

Scale 125% for M2.5 bolts and 150% for M3. In that case klipper calibration scale factors will be 0.875 and 1.05 respectively.

That said, this object can be used separately, w/o klipper, for delta bot calibration. Just print and measure and adjust.