My AMR stick from a kit now has about ten flights. There is a 700 gram lead weight fastened to the bottom of the fuselage behind the fire wall with two bolts. It tries to eat its way through the plywood. No other problems are occurring from the vibration so all else seems normal. A piece of foam padding between the plywood and the lead allowed enough movement that the bolt sawed an arc in the bottom of the fuselage during a four minute flight. Please give me some suggestion on how to fasten this weight to the model so that it will not cause trouble.

Jerry