It's been a while since the last update I have redesigned the gearbox with 2 radial bearings and a thrust bearing. The worm is print in 2 parts this gives a better tooth profile and reduce backlash. The motor driver is now a VNH2SP30 on a custom pcb and still the arduino pro mini. Its now mounted on the gearbox to reduce wiring and make it more modular. After the redesign its not 100% compatible with Inmoov. Communication is now with RS485 each unit is daisy chained from the last again to reduce the wiring clutter. Using cheap motors causes a problem with the PID accuracy mainly due to the higher starting voltage and the resultant jerk on start of movement.