Thanks - your right. The switch speed could be too high, though I could program a pause.

I'm going to see how it can go together next weekend. The motor controller is not the typical unit and built for an Arduino but nothing to stop me wiring the pwm signal to the RX directly. It is a real experiment. I intend it to run max speed no ramp up, could be a dead end, but worth a bash.

I'll give details when I try it out.

I'm sure I'll get the controls for weapon sorted. I am having more issues trying to imagine how to fix the weapon shaft to the motor. So I fit a small spur gear to drive shaft say a 1.5mod 20t then a larger 1.5kod 80t as the final drive. So 4:1 that will make it around 700rpm. That gear will have a central bore of 15mm. Now I can get a gear that has a hub with two M6 threaded mounts if I want a live axle, in which case I would have to then fix the weapon arm to the axle. Alternatively I could not fix the larger gear to the axle, but fix the weapon to the gear. This is could drill and fix with bolts or I'd need to get welded. ( Wish I'd bought that welder at Lidl a few weeks ago). The prior option has two failure points and unless I drill a hole in the axle I am not sure this is really that strong. The latter option seems to me stronger but if the weapon failed it would mean a new gear.