Diaphragm Air Engine

thingiverse

Please use this product at your own risk and always wear eye and ear protection! Do not pressurise this engine without carrying out safe pressure tests. 3D print qualities vary and will not guarantee that the bottle cap/cylinder head can cope with high pressures. Video for more info: https://www.youtube.com/watch?v=5B1H5syp4PM Print info: Material: PLA (I prefer PLA as it's easy to get strong layer strength) Nozzle diameter - 0.4mm Print width - 0.5mm Layer height - 0.2mm Cylinder Head Print info: Top/Bottom layers - 6 Outer walls - 6 (enable single wall preimeters for the cylinder volume fins) Infill - 30% Nozzle Temperature - 220c (Recommend 5-10c hotter than usual for extra strength) Bed temperature - 50c Other Parts Print info: (Can use your usual print settings, these are mine) Top/Bottom layers - 3 Outer walls - 2 Infill - 15% Nozzle Temperature - 210c Bed temperature - 50c Required Hardware: 13pcs M2x10 Bolts 6pcs M2 Nuts 4pcs MR128 8x12x2.5mm bearings 1pcs 0.5mm Viton Rubber Sheet 2pcs Oring (7mm Outside diameter 2mm Cross section) 1pcs 6mm Ball bearing 1pcs Brass tube 3mm Outside Dia 2mm Inside Dia (Need atleast 25mm to cut for conrod inserts and piston tube) 1pcs 1mm Steel wire (piston pin) 1pcs M3x10mm bolt (propeller adaptor attachment) 2pcs M3x6mm bolts (mount T-style propeller) *1pcs 1/8 BSP pneumatic fitting *1pcs O-ring (21mm Outside diameter 2.5mm Cross section diameter) *Depending on which cylinder head you choose to use, you'll need either of these, not both. Hole in the diaphragm needs to be 4mm and I recommend using a hole punch as cutting with a knife can result in the diaphragm tearing after little use. The length of the brass tube and pin on the piston needs to be exactly the correct length or the engine won't run. I've attached an image of the length (brass tube 4mm from piston top, pin 10mm from piston top).