My last post was about a problem with bad radio interference from the motors and this seems to be sorted now. I replaced the existing caps on the motors for some better ones but what really sorted it was inserting Ferrite rings in the servo cables. This was something I got into the habit of doing with electric helicopters where we used to get a lot of RC glitching. If this hadn't worked, my last resort would have been Opto couplers but these are about £9 each, ferrite rings are only £1.50 each!
Couple of pics attached to show progress so far.
Cheers

Greebo