I bought some cheap diatone X frames (polycarbonate type)
they only had holes for 22xx motors, not 1806, so made these adapter for fitting 1806 motors.
Would also work upside down, to fit 22xx motors to a frame drilled for 1806 I guess!
22xx motor bolt spacing = 16/19mm
1806 motor bolt spacing = 12/16mm
2mm (M2) bolts for the 1806
3mm (M3) bolts for the 22xx
thickness below bolt head is 2.5mm (so a 8mm bolt will have 5.5mm thread showing, which is usually ok for frames with 3mm thickness (leaving 2.5mm to screw into the motor)
pla works fine, abs maybe better
I rotated the model in my slicer so the disk was upside down - the M2 holes facing upwards - so the bolt head area prints nicely.