I had a GB Tiger 400 parkflyer that I put a Norvel .074 in and I used double sided tape to stick the Rx to the fuse wall..it flew great for about 4 or 5 flights, then suddenly during its last flight, it did a figure 9 full throttle into the ground,,I'm pretty sure it was a vibration problem and dont do that anymore....as to sending in an Rx..last time I checked I think it was only about $10 more to buy a new Rx than to have one checked....I just buy new....Rog