44mm Potato cannon projectile (swirled fins) REVISED

thingiverse

Trying some different projectile models for my 44mm air powered potato cannon. If you have a cannon with a different bore, just scale the model. Any and all experiences and thoughts on how to make the flight of the projectiles better are appreciated. Print in two parts, top needs support, lower shouldn't need. After printing you should be able to lock them together. Might do a tighter fitting version in the future. I will also be posting other projectile types, look out for those as well. For V2.7: Initial flight tests show that it is spinning out of control as is, but with weight in the hollowed chamber, it has a really nice flight. For V3.0: With weight, this projectile is a beast, currently i haven't tested anything more than 2 bar pressure with my air powered potato cannon as it launches about 150m on that pressure level. Be careful with the pressure with this one, I'll have more info on how long it can fly with high pressure launch when i find somewhere suited for that kind of test. Edit log: #1: Thicker connection between parts, hollowed out top and bottom follows outer contour, bottom outer contour slightly flatter curve. #2: Trying to gain stability by having fins further back, the angle of the fins are also less aggressive and some material inside has been shaved off. #3: Uploading a back-end with an even less aggressive angle on the fins, one 7.5° and one 12.5° before beginning high velocity testing. #4: Longer shaft, fillets everywhere, back end with better shape to make air less turbulent in the pocket between back and start of fins, better hollow, cut hole in middle of connection between top and bottom