Hi, I'm working on converting a Tomahawk 60 into a fully automatic nerf blaster using an Arduino Nano based PCB.
I have nearly everything working the way I want it, but I cannot get the drum to advance properly.
The stock design has flywheel motors up front, and pulling the trigger has a mechanical linkage to activate the ratchet pawl to advance the drum magazine.
Once the magazine is in position, the last half of the trigger pull activates a second mechanical linkage that extends a pusher rod through the magazine, feeding a foam dart into the flywheel unit.
The pusher was simple, a solenoid with a 60mm throw is just the right size, and can reliably extend, hold, and retract to ensure the dart leaves the blaster in about 0.14 seconds.
But that drum magazine is a persistent failure point, I tried using a relatively beefy solenoid (12V, 60N) but I cannot get it to reliably rotate and index on the correct position for the life of me.
I had assumed there was a lot of friction in the linkage, and made a small actuator from UHMW polyethylene, to directly connect the piston of the solenoid to the cam/lever which activates the pawl, but it still fails more than it succeeds.
My thinking now is that I either have to install a geared/stepper motor to apply torque more directly to the pawl arm, or possibly even replacing the current retractable pawl with a sprung ratchet gear that can be put on a reduction box?
That said, I'm relatively new to electronics and Arduino in general, so I wanted to check here and see if anyone had any suggestions for this problem.
There's a whole gallery of photos showing just about every part at every step of the build at https://photos.app.goo.gl/SdEb1wXE3UN2jBCg6 - the drum and the mechanism are in a couple close-ups as well.
The drum only weighs about 600 grams fully loaded, so it's not like I'm trying to rotate a giant metal chunk, especially given how my 7 year old can rotate it manually using the trigger on the stock blaster.
Thanks for reading, and thanks in advance for any suggestions.