Compressed Air Engine (working)

thingiverse

Engine is now in a running state and can also sustain itself right side up now - running quite well - vid attached https://www.youtube.com/watch?v=M-DI3TNrwx4 Please post / tag your makes! ***8/2/20 Improved strength of conrod and allowed fitment of two bearings on each end, keyed crankshaft and flywheel plus general fitment improvements allowing higher RPM and power*** ***31/1/20 More updates to valve ring fitment to hold better, added piston ring for better sealing and fine tuned to make it run efficiently with more power*** ***12/1/20 Fine adjustments to fit and prepping for piston rubber ring setup, smoothed idle out by making slight changes to valve*** ***3/1/20 Slight adjustments to valve delay using piston nipple length and closed the gap at TDC, adjusted exhaust height, crankshaft strengthened and other small changes*** ***1/1/20 Complete re-design of valve system, spring and printed valve is no longer being used and a new chamber exists for pressurized air. Standard plastic 6mm BB and a delayed re-seal setup is being used, still testing but engine runs!!! Will list new seal in requirements, this has shown to be a tight seal and pretty efficient*** ***23/12/19 Multiple changes to smooth out and strengthen design, tighten clearances plus make it easier to print, updated flywheel to stop any crankshaft movement and added a prop spacer*** ***21/11/19 Updating mounting points for better O-ring fit and general improvements*** ***13/10/19 Lots of overall changes, smoothing and fitment etc with a flywheel allowing prop usage*** ***19/9/19 Adjusted mounting locations to lock down bearings better, slightly tighter thread holes and other small fixes*** ***15/9/19 Fixes to piston and conrod, loosened m3 fit for top and bottom end and changed air nipple*** This is my attempt at designing and drawing a working and sizeable compressed air engine that is mostly printable with few external parts required. Feel free to try it out and give me feed back, note it's a work in progress and I'm still working out the kinks. Only a few parts require supports, just rotate and flatten as needed inside your slicer and use common sense for orientation. Bellow can be found easily on https://aliexpress.com ***Required:*** ***2x 608 universal skateboard bearings (crankshaft bearings)*** https://www.aliexpress.com/item/33051895647.html?spm=a2g0o.productlist.0.0.f668433ezCGFwU&algo_pvid=b2c6d0fd-5d5b-47a6-94b1-f57ca5a26d32&algo_expid=b2c6d0fd-5d5b-47a6-94b1-f57ca5a26d32-3&btsid=a7104a1b-d334-4ad3-8f70-ca2f6ce4ce47&ws_ab_test=searchweb0_0,searchweb201602_6,searchweb201603_53 ***4x 682ZZ 2x5x2mm bearings (conrod bearings)*** https://www.aliexpress.com/item/32862636969.html?spm=a2g0s.9042311.0.0.27424c4dIet80A ***1x 2mm thick lengthy steel rod (cut as needed, for piston pin and conrod crank pin)*** https://www.aliexpress.com/item/32297671032.html?spm=a2g0s.9042311.0.0.27424c4dIet80A ***2x 35mm x1mm OD O-Ring (head seals)*** https://www.aliexpress.com/item/32844105437.html?spm=a2g0s.9042311.0.0.27424c4dYMR0Mb ***1x 5mm x1mm OD O-Ring (new BB valve seal)*** https://www.aliexpress.com/item/32725251085.html?spm=a2g0s.9042311.0.0.27424c4dIet80A ***1x 28mm x1mm OD O-Ring (Piston ring)*** https://www.aliexpress.com/item/32844105437.html?spm=a2g0s.9042311.0.0.27424c4dI2J7fy ***10x M3x20mm bolts (for fusing points)*** https://www.aliexpress.com/item/33003801934.html?spm=a2g0s.9042311.0.0.27424c4dIet80A ***1x M3x70 or shorter for crank shaft prop mounting (reinforces crankshaft, 70 works best)*** https://www.aliexpress.com/item/32958820614.html?spm=a2g0o.productlist.0.0.29e728c1G2qTby&algo_pvid=2dfa08c1-6693-4cf0-9af9-04e9b9c27482&algo_expid=2dfa08c1-6693-4cf0-9af9-04e9b9c27482-0&btsid=b3182296-6f6f-4977-bd19-0c5a0448e86b&ws_ab_test=searchweb0_0,searchweb201602_6,searchweb201603_53 ***1x Standard 6mm air soft BB (new valve)*** ***1x Some form of propeller or spin-able weight to act as a true flywheel*** I'll add other requirements if needed as I print and test - I am by no means an expert CAD user so I'm still learning as I go. Thanks for looking!