I got the controls sorted by modding the left stick so it's sprung now.

Further questions:

I'm using 2 cordless drill motors and holding the wheels on with the reverse thread screws. They keep working loose. Anyone know how to prevent this or if there are stronger reverse thread bolts to hold them on with? The screw isn't made of the strongest metal and I've almost ruined one of the Philips heads.

Also looking forward to the weapon, I'm going to use a linear actuator to raise the lifting mechanism.

What do I need to connect the linear actuator to the receiver and control it? Something like what the escs do on the motors. Would a simple on/off do the job? Or is there something better for this?

I'll be using a switch on the transmitter to activate the lifter.