Laser module for 44mm diameter CNC spindle motor holder

I have a couple of 12mm diameter 1500mW laser modules and heatsinks, plus a cheap Chinese CNC router. However, fitting the lasers is difficult as the heatsinks don't fit properly into the spindle motor holder. Also, the laser modules are 5V, whereas my CNC only provides a 12V PWM laser output. So, I built this project to hold the laser module and a small power step-down circuit that would fit properly in place of the spindle motor.

I've included the OpenSCAD file for customisation as modules,