Retractable Landing Gear - Mechanical

thingiverse

I copied this design from the cheap injection moulded Hobbyking retracts available online. The parts should be printed at 100% infill. It can be built as either steerable or fixed with a few optional extra parts. These should be operable with a normal servo. Be careful to adjust the servo travel so it doesn't stall the motor when it bottoms out. # Required Hardware (per unit): # * 3pcs M2x14mm CSK screws * M3xOD5mmx15mm round threaded standoff (aluminium or brass ideally - Crossdrill 2.5mm midway along its length) * M2x40 threaded rod (Alternatively, an OD2x40mm rod & M2 threading die) * OD2.5mm steel wire (to be bent into landing leg shapes) Fixed gear only: * M3x6mm Grub Screw Steering gear only: * 2pcs M3x4mm grub screw * M2x20mm Screw * ID2mm circlip # Tips: # * I suggest tapping all the holes with a thread tap or heating the screws with a lighter and then threading them into the plastic before final assembly to form the threads and prevent the printed parts splitting. The M2 case screws can be substituted with plastic self tapping screws. * For the fixed gear, the M3 grub screw threads into the pivot axle and clamps against the landing leg. It might be worth filing a small flat patch in the leg to make it less likely to rotate. * The aluminium standoffs will need to be crossdrilled to 2.5mm midway through for the wheel leg to pass through. * For the nose gear to be steerable, you will need to put a groove around the top end with a saw or rotary tool, for the circlip to fit into. This stops the leg from falling out of the pivot knuckle. * The M2x20 screw should get threadlocked or epoxied in place. This is a slider that allows the nose gear steering servo linkage to rotate as the gear is retracted.