Uploaded March 2026 | Updated September 2026, 2 weeks ago
This is the same 3-stage kit I bought from aliexpress for like 15 bucks at the time. Using a small 3s lipo battery in the grip.
Never really did much when it comes to trying to tweak the maximum fps on this. Still also haven't really decided if trying to make a larger one would be worth it. I'd want it to be able to penetrate 1/4 inch steel which would make it pretty massive and a large undertaking. When it comes to this thing a slingshot will do more damage but I kind of like it kept in the realm of fun toy as opposed to truly dangerous. Obviously you could still shoot an eye out or something though. I'll probably just print some parts to where there's an inverted feed ramp I can just drop random stuff down into as opposed to some kind of magazine limited to certain projectiles.
There is more of just a cool factor to the electromagnets compared to let's say gear-driven spring loaded action which would probably work better around this size (like airsoft). The timing is all sort of hit or miss since each projectile will be different. The placement of the dowel at the first stage can make a noticeable difference in the velocity which helps show how much the timing on the other 2 stages come into play as well. I'd guess much better performance could actually be had from just these 3 stages if the timing was adjustable to some degree of precision.
This is the same 3-stage kit I bought from aliexpress for like 15 bucks at the time. Using a small 3s lipo battery in the grip.
Never really did much when it comes to trying to tweak the maximum fps on this. Still also haven't really decided if trying to make a larger one would be worth it. I'd want it to be able to penetrate 1/4 inch steel which would make it pretty massive and a large undertaking. When it comes to this thing a slingshot will do more damage but I kind of like it kept in the realm of fun toy as opposed to truly dangerous. Obviously you could still shoot an eye out or something though. I'll probably just print some parts to where there's an inverted feed ramp I can just drop random stuff down into as opposed to some kind of magazine limited to certain projectiles.
There is more of just a cool factor to the electromagnets compared to let's say gear-driven spring loaded action which would probably work better around this size (like airsoft). The timing is all sort of hit or miss since each projectile will be different. The placement of the dowel at the first stage can make a noticeable difference in the velocity which helps show how much the timing on the other 2 stages come into play as well. I'd guess much better performance could actually be had from just these 3 stages if the timing was adjustable to some degree of precision.
