AVD - Lightweight
Builder: Andrew Rossol
AVD ("Andrew's Vertical Disk") was a 60lb vertical spinner built for RoboGames 2018. This was my first robot of this size after a handful of ant weights and beetles, and was a good learning experience. AVD's four-wheel drive was powered by 4x775-motors on VEX Versa Gearboxes. The weapon was powered by a Castle 2028 Brushless in-runner, the same motor that powers Deep Six's weapon and drive.
The frame body was .5" 6061 aluminum and the disk was 1" AR400. After 2018 the 60 pound weight class was effectively extinct with RoboGames ending their competition. It had one more competition in Colorado at AVC Sparcfun where it fought as a "sportsman" robot with wedges replacing the disk. That event has ended as well, and AVD is in an indefinite retirement.
The frame was donated in 2019 to the Boy Scouts of America for them to practice their machining skills and fixing it up. Will it fight again? Only time will tell.
AVD ("Andrew's Vertical Disk") was a 60lb vertical spinner built for RoboGames 2018. This was my first robot of this size after a handful of ant weights and beetles, and was a good learning experience. AVD's four-wheel drive was powered by 4x775-motors on VEX Versa Gearboxes. The weapon was powered by a Castle 2028 Brushless in-runner, the same motor that powers Deep Six's weapon and drive.
The frame body was .5" 6061 aluminum and the disk was 1" AR400. After 2018 the 60 pound weight class was effectively extinct with RoboGames ending their competition. It had one more competition in Colorado at AVC Sparcfun where it fought as a "sportsman" robot with wedges replacing the disk. That event has ended as well, and AVD is in an indefinite retirement.
The frame was donated in 2019 to the Boy Scouts of America for them to practice their machining skills and fixing it up. Will it fight again? Only time will tell.
Lessons learned
This was my first robot designed and built by myself, and with that came a number of lessons and tips about what worked and what didn't work. Some of my most important take aways were:
- The floor isn't perfect, so plan for it. Panels can have dents and gaps. Low ground clearance can bite you when you can't drive.
- "Four inch diameter" wheels won't always be 4 inches. The wheels I purchased were 4" at the crown, but after a few minutes of driving this wore away leaving the wheels closer to 3.8." The primary chassis was 3" tall, and after the bolts connected the base plate to the chassis there was minimal clearance between the floor and the robot. This lead to AVD bottoming out in parts of the arena with minimal control.
- Brushless motors and speed controllers aren't necessarily "plug and play." I didn't bother getting the programming card for the Mamba XLX which lead to calibrating using the radio, and that lead to a number of settings not being ideal for a spinning weapon. At spin up the current limiting would kick in at low speeds, which caused the weapon to stop getting power. I would repeatedly have to feather the weapon from 0% up to 25", then back to 0%. Trying to do this while driving away from the opponent was not ideal. After seeing the true potential of these motors and controllers in Deep Six I know AVD could pack a real punch.
- Measure twice cut once. Half way through the design I changed my gearboxes that I was going to use. This meant compromising in other areas to make the other drive gearboxes fit.
- While three teeth look cool, they can compromise the "bite" ability of the weapon. Some hits that I did get on opponents ended up grinding their armor more than catching and throwing. If I were to totally re-design the weapon it would be a single tooth with much greater reach, along with some kind of feeder wedge to get a better angle.
Test spinning at half speed. Safety precautions included having the robot's wheels off the ground and not being in the same room. These machines can be dangerous and must be operated with caution.
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