Whiskit
7-6 win/loss record
Small, Dense, Reliable
Whiskit is designed to have as few moving parts as possible. This means that the best solution for the weapon was to make the entire weapon assembly self-contained with a simple hub motor system. Two durable motors drive two big, durable wheels. Whiskit only needs 2 fame rails since the wheels and weapon both mounted the same width apart, reducing complexity and improving durability.
Another Hub Motor!
Since the drum is so wide, I was able to avoid putting the motor between the two large bearings. This was a good choice for my first hub motor system because I did not need to pass wires underneath the bearings.
How is that balanced?
Whiskit has one of the fastest spinning weapons on the team, since the moment of inertia is so low, being only 2.5 inches in diameter. This makes balancing the weapon properly absolutely crucial. Even worse, the spinner weapon is not only asymmetrical, but uses several different materials and has an asymmetrical cutout in the center! A long impactor along the front distributes the load along the 5 screws holding it to the 7075-aluminum drum, and a steel counterweight balances it out since at such a small diameter, the aluminum alone is insufficient.
The issue I was running into when designing this weapon is ensuring that the axes of inertia were exactly along the axis of rotation, which isn't an issue when designing 2d profile weapons or symmetrical drums or beater bars. This is known as secondary balancing and becomes an issue with rotating bodies with more than one plane of asymmetry, like a crankshaft.
The solution to keep the products of inertia at zero was to ensure that every single operation made in CAD kept the center of mass along the center of rotation. Instead of balancing the weapon once, I had to balance it three times!
Early Whiskit
The first version of Whiskit sported a larger 3-inch effective diameter manually machined weapon, using alloy steel screws as the impactors. This version faced the same design challenges as the newer weapon, although the lack of a counterweight made it significantly easier to design and build.