Iteration Weapon Pulley and Belt

The Swole Bar needs about 4” diameter of clearance to spin properly. The spinning diameter of the weapon can be utilized to keep the weapon pulley protected. If the Weapon pulley is 2 inches in diameter that should keep it adequately protected while still providing enough reduction to be a useable speed. The target speed of the weapon needs to be around 16000 rpm to have enough energy to cause significant damage without having to much gyroscopic precession to cause driving issues. It may be necessary to have a higher tip speed at times though to win weapon on weapon engagements with other vertical spinners, so a top end of 17000 through 20000 would be a nice bonus.

The slowest amazon special motor I could find and get in time for this project is a 1800kv 3665 in runner. At 6 cells it would be spinning at 39,960 rpm at full throttle (3.7 volts * 6 cells * 1800kv). The smallest pulley I can get off the shelf for this motor is 1 inch in diameter. A 2:1 reduction would put the weapon at 19,980 RPM, so this will work for the upper speed. 80% throttle should lower the angular velocity enough to get good weapon engagement, kinetic energy, and drivability.

2L v belts are being utilized to transfer power from the weapon motor to the weapon. They come in increments of 1 inch in circumference. The Swole Bar needs 2 inches radially to spin, there is a 0.5 inch UHMW cross member, and the weapon motor needs a minimum of 0.8 inches radially. A minimum of 3.3 inches is needed between the center of the weapon pulley to the center of the motor pulley. 3.3 inches center to center with a 2 inch and 1 inch pulley would give a belt length of 11.388 inches. This will be rounded up to 12 inches, giving a center to center distance of slightly over 3.6 inches.

Space is at a premium inside of the Iteration’s frame, so adjusting the cross frame distance to the weapon mount makes more sense than pushing the motor further into the electronics bay. This will give more clearance space for adding impactors to the bar, more air gap to prevent compression, reduction of overall frame weight, and more internal space.