RC airplane bungee launcher pedal

thingiverse

I've never been very good at hand launching except on flying wings, so whenever possible I bungee launch, plus I think it looks cool to do so. In case it comes up, this launcher was not inspired by the laser cut launcher on Thingiverse, although they are somewhat similar. I had never even seen it until I did a search for Bungee before posting mine. I'll give the launcher it's due though, https://www.thingiverse.com/thing:2759891, since it looks to be a well designed launcher for those with access to a laser cutter. I use my launcher with electric planes, which don't have the motor running while being launched. I have used it with pusher and tractor setups. I printed the one pictured here on a Solidoodle Workbench with 12" build surface. Not everyone has the luxury of this large of a printer, so I also included the Launcher base in two parts, which can be glued together with medium or thick CA. The pedal, as well as the remaining parts, should fit on an 8" print bed ok. I made two hook mounts, the short one can be used generically and the other longer mount should do better in foam. I printed the hook and mount with PETG, but PLA or ABS shouldn't be a problem. The main thing is for the hook and mount to be solid. Something with that much pressure on it is not where you want to skimp on plastic. I printed my Red safety cap with TPU, so that it will press fit snugly onto the retaining bolt. I would recommend not to skip using the safety cap. I learned the hard way that I needed one while placing a plane on the Bungee ring. I lifted the ring up slightly to put the hook in and the retainer ring slipped off of the bolt and rapped me right in the knuckle. Very painful. Everything else can be printed at 50% infill or more. Here is the link for the Blue bungee cord https://hobbyking.com/en_us/hobbykingr-8mm-silicon-rubber-bungee-hi-start-cord.html?___store=en_us and bungee kit, which includes the metal stake and rings https://hobbyking.com/en_us/lightweight-bungee-kit-9-5m.html?___store=en_us. Alternatively, a plastic tent stake from a hardware store should work equally as well and the rings, which are basically keychain rings, can be found at craft stores. The two steel spikes used to hold the launcher base to the ground and the one 1-1/2" long and two 1/2" long #8 or 5/32" machine screws are available at any hardware store or home improvement store. https://youtu.be/Bow5V5VPCXk