Hey NerfHaven it's been a while, but I just got to college and there's a decent HvZ scene here so I'm getting back into Nerf.My first project, a custom flywheel cage for a Stryfe with brushless outrunners as the flywheels.
I've seen a couple people do this before, but none of them have any documentation, so I'm mostly starting from scratch. I'm starting off with these 26x27mm motors, which are rated for 47k rpm and 300W on 3S, as well as some Simonk speed controllers and a Zippy Compact 1Ah pack I have laying around. The other, more powerful, motor options are this one, which is 56k and 365W at 4S, and this one, which is 44k rpm and 755W at 4S, but I'm not sure they'll fit without cutting the shell as they're both 36mm long. I also don't have a 4S pack of the right size on hand, so we'll see if the first motors have enough power. If they can spin up fast enough, I'd love to put the rev switch behind the trigger like the FDL-2 and eliminate the separate rev trigger.
Another question is the flywheel surface. I have about 3mm of thickness in my current design to add another material with better grip to the outside of the motors. I'll do some tests with the stock steel cans, then with polished steel, before moving onto gluing on rubber tubing, like Mcmaster's 35A and 50A hardness silicone tubing. I'm surprised nobody's tried anything like this before, I think it would give a significant increase to the friction against the dart, and therefore the velocity, but I'm not sure they'll stay glued on properly. It sounds like a silicone based adhesive like E6000 or silicone caulk is my best bet.
And of course, flywheel spacing has a big impact on dart speed, but I haven't seen more than a few anecdotal numbers, so the motor mounting holes are slots so that the spacing is adjustable and it will accommodate different sized flywheels.
As you can see, there's a lot of things to experiment with, and I haven't even gotten into barrel guides or canted flywheels. I'm super excited to get back into this community. Here's what I have so far for the CAD model, I'm currently debating whether to 3D print it or CNC it out of aluminum.
Edited by shardbearer, 12 March 2017 - 07:09 AM.