Board Thread:General Nerf discussion/@comment-38684270-20200110172538/@comment-27306930-20200111010250

The RapidStrike uses a motorized pusher that incorporates a standard 130 motor. The motor has a worm gear that turns two smaller gears that rotate a larger drive gear. As the drive gear turns, it reciprocates the pusher using a nub that engages with the curved rail on the back of the pusher rod. It's all contained within the pusher housing, and filled with grease.

The stock motor turns about 17k RPMs, so the gears are necessary to reduce the speed of the large drive gear to about 210 RPMs, which equates to about 3.5 pushes per second.

Here's a pic I stole from reddit that shows a 180 motor in a RapidStrike pusher. It certainly provides more RPMs, but a 180 is WAY overkill on torque. I used a wimpy old Solarbotics RM2 and I'm getting 8 DPS. So don't be fooled into thinking you need a high performance motor for the pusher. Just use a higher RPM motor.

But here's my next problem. When I upgraded the motor, the increased speed and momentum creates a situation where the pusher goes into a continuous feedback loop. The cutout switch that's supposed to kill the motor when the pusher fully retracts, doesn't cut out long enough to prevent the momentum of the pusher mech from starting a new cycle. Kind of like a car "dieseling". Check out the video.

My solution is to use the second set of poles (contacts) on the Rev trigger switch and pusher sensor switch to create a motor brake. If you're interested, I can draw a schematic.

I'll post a vid of the improved version over the weekend.