Moldmaker....Instead of using the rubber grommets,use 1\4" or 1\2" foam.Glue the foam to the aircraft where you want to mount it.Put masking tape on the bottom of the ignition and then glue it to the foam.Then all you have to do is peel the tape off the ignition when your done with it in that plane and it's good as new.I also use a velcro strap to help hold the ignition in place.This way the ignition moves very freely.I also mount my receivers this way and you don't need the velcro.It can move very freely and there's no pressure on the receiver.Batteries work well this way also,you will want to use velcro though,just because of the weight.Works extremely well...Try it.

Jack