How to retrofit your foam 3D RC plane to make it (almost) crash-proof
You can retrofit your foam 3D RC plane to make it almost crash-proof by several easy modifications. Put a disk of dense foam rubber between the motor and motor mount. The foam should be approximately 5/8 inch (15mm) thick. Put holes in the foam rubber and re-attach the motor using zip ties. Reinforce the front of the fuselage with 4 popsicle sticks. Use packing tape with fibers to reinforce the fuselage.
Ultra Lightweight RC motor glider DIY Build video How to make Scratchbuilt Ultra Lightweight 2 meter RC motor glider (FAA registration not required, under 250g Weight Limit)
