Download Free 3D Model 30mm Calibration cube for SLA printers – Hollow 3D Print Model

Summary
This is a hollow cube with drain holes to minimise suction. Stick it on some supports, print it and measure
When I used this on my Moai with v1.15 firmware, using “m” as the relevant cube measurement, the formula to calculate what put in the relevant X or Y entry is:
900*(30/m)
I haven’t used it on my D7 yest, but I’m sure you can work out what formula you would need to use.