The Butcher
To do this I did a few things: First, cut down the weight of the weapon. This would decrease spin up time and leave a little more weight for a more robust pulley setup. Second, I wanted to make a custom pulley that had deeper grooves. The off the shelf parts I had been using had such shallow grooves that the belt would fall out almost every match. I decided to make my own pulley, complete with deeper grooves and a custom spline to transfer the power to the weapon disk. Finally, as part of this pulley upgrade I wanted to add another bushing to the weapon assembly. This would help to keep the disk from tilting on big hits which would potentially clip the weapon belt. I designed the pulley in a way that I would have the weight to make it out of aluminum, but for both cost and weight reasons, I wanted to experiment with 3D printing it. I had the custom pulley printed out of NylonX from 3DHubs. The new weapon disk was cut by SendCutSend out of AR500. Both parts came out great and fit together perfectly.
The Butcher vs Minor Threat
Result: Win by KO
The Butcher vs Quicksilver
Result: Loss by judges decision
The Butcher vs Maverick
Result: Loss by Judge's decision
The Butcher ended up 1-2 on the weekend, but I was still happy with how it performed. The main goal of the Butcher was always to make big impacts. I was successful in my first fight, but the reliability still isn't to where it needs to be to consistently compete. I have some improvements in mind, that include rebuilding most of it.
Things That Worked:
- The new weapon assembly worked great, no noticeable wear on the pulley or belts. Extra bushing seemed to really help the stability
- Weight balance with the slightly smaller weapon and the larger wheels made it much more drivable
- The weapon motor pulley needs to be more secured to the weapon motor
- The belt tensioning could use a rework as the tensioners that I have started to melt by the end of the event
- The drive motors are too high of kV and could use a larger diameter motor for more low end torque and control
Drop Test
Drop Test vs Death by Single Cut (DBSC)
Result: Loss by KO
Drop Test vs Blue Waffle
Result: Win by KO
Drop Test vs Shredder 249
Result: Win by Judges decision
Drop Test vs Propaganda Machine
Result: Loss by KO
This being Drop Test's second loss and the second frame that was split in half it was out of the competition. Overall I was still very happy with how it performed even if the number of pieces it was broken into was greater than the number of flips it successfully perfomed.
Things That Worked:
- The flipper worked well, definitely could be better, but as a first proof of concept it went great
- Designing for repairs. Because of the design of this bot, the electronics had to pass through the frame from one half to the other. I used a lot of connectors to make electrical work easier on myself and it turned out great when I had to completely rebuild the bot in the middle of the event.
Things That Didn't Work:
- The 3D printed frame was printed in the wrong orientation so the bot split along the layer lines. A lot. Will have to consider 3D printing limitations a little better in the next rev
- It was very difficult in the middle of the battle to get the flipper to stay in the loaded position. I plan to at least put a small detent in the mechanism to hold it in the loaded position, if not try and incorporate some sort of feedback system to track the position of the trigger arm for better control
All in all, for a new bot I was very pleased with a record of 2-2 on the weekend. And honestly, getting destroyed isn't the worst thing as it forces me to reconsider a lot of the design choices to better optimize the bot for the future. I plan to update this page soon with the planned upgrades to both these bots.