Tuesday, October 21, 2008

robo boot camp

I have a weakness for engineers, and one of things that initially attracted me to Jascha was his robotics background, notably his participation in robot fighting competitions like BattleBots. So when an invitation to compete at the Maker's Faire came around I agreed to help out. We lucked out that the event was in Austin because it meant we had access to his dad's incredible shop, a major luxury in a world where traveling to events means working with whatever tools portable you can fit in your storage container.

We caught an early flight into Austin the day before the event. Armed with 3.5 hours of sleep from the night before we set to work on Jascha's robot, The Judge, repairing a leaky pneumatics valve and damage sustained by an overzealous robotsitter. At 2am after ~8 hours of shop time we called it a day.

We arose wearily at 10am and headed over to the event.
There were four other competitors in the the 340 lb category and the event was set up as a round robin. The Judge is notorious for its vicious, pneumatically-controlled hammer with interchangeable tool steel tips and many of the competitors came prepared with reinforcements to shield against internal damage. The pit was pretty much what I expected - almost exclusively nerdy guys frantically tinkering with the fruits of their savings and many hours of sleepless nights. My hat goes off to Wendy, one of the few female drivers in the sport. We had a bit of time to kill before the first round so we headed out into the fair in search of food. We were pleasantly surprised to find amazing banh mi (Chinese BBQ pork highly recommended) from Lulu B's amongst the typical carnival fare and gluten/soy/dairy/taste free food.

The first round of the day was against the Vladiator, a lifter type robot. Things went well until the pneumatic system failed, leaving the hammer stuck in the fully released position. It was disappointing to see a loss so early. We had less than three hours until the next round so we quickly removed the armor and took the robot outside for diagnostics. Frustratingly, the culprit was a second valve in the custom pneumatics valve assembly that we had so carefully disassembled and cleaned the night before. We didn't
have time to do a full disassembly so Jascha rotated the poppet valve repeatedly in its seat, hoping that it would reseal. Getting the batteries recharged and the armor back on in time for the next round was stressful, and it didn't help that the irritating Tesla coil exhibitors across the hall were blasting sci-fi movie and video game themes as accompaniment. Finally we were ready to go.

Our next round was against Steel Reign. The hammer appeared to be functioning again, but we knew from experience that it might take a few blows to show symptoms of valve leakage. Shortly after the battle began Steel Reign stopped working completely and its owner tapped out. This turned out to be a temporary problem, and Jascha gave the OK to start up the round again. This time the hammer appeared to be working better although now it wouldn't retract fully. Fortunately, we still won the match. We pulled off the armor and didn't see anything obvious hindering the rack and pinion system that actuates the hammer. When we turned it over and pulled off the dented bottom plate, however, we found the problem. Blows from below had put a large tear in the frame, but more importantly, had dented the large piston and housing cylinder that drive the hammer arm. This looked bad as we couldn't exactly pick up a replacement cylinder or piston at an auto parts store. We knew that we had another long night of repairs ahead of us.

After a quick dinner of Thai food, Jascha and I removed and disassembled the piston assembly. We worked on the frame repair, while Jascha's dad attempted to smooth out the dented cylinder with a press. The piston was easily bent back into shape, but the cylinder was more stubborn. After several hours of lathe work and sanding Jascha's dad was able to get the piston to run somewhat smoothly through the cylinder. Jascha and I reinforced the damaged frame by adding an additional armor plate, which had the added benefit of protecting the regulator. We turned in around 3am.

The first round of the day was against Ziggy, which The Judge had lost to in its previous encounter. Ziggy has a pneumatically-driven flipper arm that can easily send 300+ lb robots into the air. We crossed our fingers that the hammer was functioning properly, as it is also used to right the robot after being turned over. The round was close with Ziggy repeatedly throwing the Judge into the air and The Judge fighting back with heavy blows. In the end it came down to the judges' decision and the round went to Jascha.

For once there wasn't any debilitating damage, so we recharged The Judge's batteries, refilled the nitrogen cylinder, and relaxed. We were visited by a number of spectators of all ages and Jascha answered questions about the inner workings of The Judge and offered advice about breaking into the sport. Our next round was against Gerald and Emily, two robots that fight together. I learned that a team can have as many robots as they want in one round as long as their cumulative weight meets the class specifications. As the round got closer, however, we saw that Gerald had been modified with a huge steel plate as protection against The Judge. This meant that Gerald would be fighting alone. As an added advantage to us we found out that the plate partially obstructed the spinning drum and blade on the front of Gerald. The battle started and sparks flew as Gerald's blades scraped The Judge's titanium armor. Jascha got in a number of substantial blows and Gerald eventually stopped moving. The titanium was gouged and some of the welds were sheared, but there wasn't any new internal damage.

We waited around for a while to see if we would have to do a final round to decide the winner, but because we had just beaten the competitor with whom we were tied for number of wins/losses the organizers declared The Judge the overall heavyweight winner.

We postponed our final repairs in order to get in a few hours of climbing, dinner prep (we made nam khao tod, or rather nam tofu, tod and prik khing for Jascha's parents), and blacksmithing lessons for me. I was worked from lack of sleep and helping to lift the robot repeatedly, and I got frustrated on not being able to clip the last bolt from a sharp finger numbing crack on what I thought was a 5.9. I later learned this was a 10c. Fortunately, we moved down to an easier part of the cliff and I redeemed myself on some 10a routes. My blacksmithing lessons were fun, but a bit challenging because my forearms were tired from climbing on overhanging limestone. Jascha's dad was most patient and I managed to produce a slightly lopsided hook. The following evening we patched the armor and repaired the sheared welds, leaving The Judge packed up and ready for the next event. I had a great weekend, picked up some new skills, and fully enjoyed the event and shop time.

Lessons Learned:
  • If the idea of blowing away countless hours and dollars with a few minutes in the ring doesn't seem very appealing to you, then robot fighting is not your sport.
  • Helping to lift a 320 lb robot repeatedly with minimal sleep for 2.5 days will not improve your climbing.
  • Don't always believe locals without guidebooks who tell you a route is a 5.9.
  • Learning to blacksmith is not compatible with climbing overhung routes.
  • Metal is incredibly forgiving to the repeated correction of mistakes made by inexperienced forgers.