3946’s frisbee trigger* in 2013. Intended as a prototype, it was literally a piece of 3/4" x 1/8" aluminum bar that was “cut” via metal fatigue, had a drilled a hole in, and bent by hand and a table edge and mounted on the shaft of a long thin pneumatic cylinder shaft. It worked for hundreds of practice shots (including dialing in the wheeled shooter), and for about the first half of Bayou, then started jamming. By the end of the event, it was locked hard in the down position. We made another trigger post-season using more customary techniques.
* that is, the part which pushed the frisbee into the wheeled shooter
In 2015 we hacked together a practice bot with an old C-base frame. The axle spacing didn’t lend itself to 4WD very well, so we ran the chain through short lengths of pvc conduit and pulled the tubes together with duct tape to tension the chain. You can barely see it in the attached photo. Worked all season!
Our main jerry-rigged thing last build season was our cargo system.
We came into competition with 2 pieces of Lexan and a lot of zip ties.
We were actually able to make a functioning cargo shooter.
In 2018, at Pomona (LA) one of our gearbox plates got whanged and dropped a bearing out its bore, leading to a pretty chewed up gearset. We had neither the time or spares to replace the damaged parts. But we managed to get it all popped back in place and since the affected gears had almost half the teeth width damaged, we needed to guarantee the remaining good parts kept perfectly aligned. So the students quickly fabbed a polycarb spacer/bias plate and mounted it to the bellypan. I thought it was a very clean and clever “Jerry Rig”. Hardly Janky at all. It managed to survive all the way through finals - where 330 kicked our butts and won.
So in 2017 my team made it into the MNHSL competition eliminations. For those unfamiliar, Minnesota has its robotics state competition in late May as an off-season event.
Something in the drive train must have been binding, and that paired with the racing back and forth across the field grabbing and placing gears was really taking a toll on the motors (4 full cims). We didn’t have an IR thermometer, but I’d easily assume they got around 180-200 in degrees freedom.
Since it was eliminations, we didn’t have time to find what was binding, so we tried to cool the motors with those instant cold packs, which worked great until we ran out sometime in late quarterfinals. Getting desperate, we turned to more unconventional methods.
By this time most teams had packed up their pits and were in the stands or had left, so the pits were mostly empty. This is important as I don’t want to give others any ungraciously unprofessional ideas. So you know those table top ice water jugs? We grabbed some plastic bags, and careful not to contaminate the water, began scooping out the ice. I would not do this if other teams needed water, but since the competition was almost done, we decided to go for it. Careful not to run, as that would be unsafe, we trotted back to the robot and applied the ice packs, which actually worked better than the instant ones.
Also, I do need to apologize to team 2052. One of our team members didn’t get the sanitation memo and just plunged his hands straight into the ice water while a couple Knightkrawlers were in line behind us. I directed them to another unsullied jug, and I know no one used the one we contaminated, but I do apologize for the inconvenience.
In 2015 recycle rush, we programmers created an addition to the robot called the “magic” tote, which was an upside down black tote that allowed grey totes to slide on top it and make a stack without the first on tipping oddly on its side. While that way pretty “jerry rigged”, it was at competition we truly made it to the top. We found the para-cord we were using was too small, and would get caught in our wheels. In order to keep our magic tote functional, we found the best tether we could, a 10 foot extension cord that we tied around the robot and the tote. It was the best and worst thing we have ever done.
At the Ontario provincial championships in our second last qualification match we shattered the fibreglass pole in our telescopic system we hammered a length of L bracket down the shaft to act like a splint for the pole, hosed clamped it to the pole and sent it out for our final match of the day. Prematch the drive team was running a pre system test and when extended to the second level of the rocket it would fall over. Played the match with little issues with only doing the first level hatches and defence. In the morning our mentor went to Home Depot and bought a new fibreglass telescoping paint pole cut the new one to length during alliance selections and had the splint extended to prevent the shattering again, shimmed it with 1/8 inch polycarbonate and lasted the 2 matches of the playoffs with little visible wear on the spot were it shattered. Photos coming soon.
I don’t have any video evidence of this but at the R2OC off-season event my team (1792) broke the top of our lift clean off. It broke through 2 welds when we tried climbing in the semifinals. We packed extremely light so we didn’t have any spares or spare material. So to put the top bar back on the lift. Which was essential for most things. We just put bolts into the open sides of the aluminum bar and wrapped the whole thing in T-Rex tape. The bar was definitely not secure. We never attempted climbing again but we went on to win the event!
This reminds me of our frisbee pusher from the same year. The carefully designed 3D printed foot wasn’t reliably pushing the bottom frisbee into the launcher, but it had worked beautifully during prototyping when they used the push stick that normally lived with the bandsaw. Naturally, they used the bandsaw to cut the push stick to length and put it on the robot. It worked great all season.
We have an offseason bot that uses an Andymark Decimate gearbox to directly drive a flywheel shooter. We found out the hard way at an outreach event that while the gearboxes were shipped assembled, they did not come assembled with Loctite. The 2 redlines fell out after some good use and we ziptied them back into the gearbox. Despite the motors spinning at about 15000+ rpm and the flywheel spinning at about 4000-5000 rpm for the majority of the remainder of the event, they did not come out and continued to work. We fixed it with Loctite when it got back to the shop.
There’s a picture of that somewhere, likely on the team’s wall of shame.
In 2017, when I was student, we realized quickly that our climber would have problems because the rope would move sideways as it wrapped around the winch drum, eventually slipping around the 1/2 in hex shaft, at which point we wouldn’t be able to climb.
So one of my teammates put pool noodles around the hex shaft and wrapped them with copious amounts of duck tape. She would wrap more duck tape around it after every match. We climbed 12/12 times in qualification matches and were an alliance captain.
You can kind of see our climber drum in this picture:
694 affectionately uses the term “Wildcard-ing” whenever we jerryrig something. It’s practically become part of our team culture (Both our 2018 robot and 2011 minibot were named Wildcard) and we love coming up with last-minute creative solutions in the most stressful situations.
I think the best competition wide Jerry rig was definitely all the “plane breakers” from 2018.
Most people just stuck long zipties on their bots but I saw things from sticks to tape measurers.
In 2017 we had a 1 way bearing machined out for us by a mentor with some sick tools that we didn’t have access to. About half way through our 1st event it broke and our climber started back driving. Not only did it break, we had a 2 match turn around. Off the field and into the queue. We slapped a cheap ratchet wrench on it with some zip ties, never broke. We actually had the wrench get stuck on the robot.
Not really a jerry rig, more of a “nonstop repair job”.
In 2016 (against the advice of the mentors) the robot had thunderhex drive axles, and the wheels had hubs made from 1/8" thick steel with a hex broach. SHOCKINGLY the steel plates ground a groove through the drive axles. We discovered this problem after our first quarterfinals match when it became apparent that we had one functional drive wheel.
The robot was so poorly thought out that replacing a wheel was a ~15-20 minute operation. Bill Berggren from 1538 was kind enough to find us some steel hex stock, and we machined a single axle and welded a wheel to it before QF2.
We machined a new axle during each match, and between each match we pulled a single wheel off, welded it, and put it back on. Each match we had to prioritize which single wheel was the most important.
Went on to win the event by a single penalty with 5/6 wheels functioning.
In 2015 we made the cutout in our chassis just a little too deep for our tote manipulator, so we were testing out adding a few different types of hard stops. One of the things I wanted to try was just putting a piece of 1/2in round stock across the chassis for them to run into. I drilled out the ends of the stock intending to tap them to 1/4-20, but used the wrong bit which was way too big. Coincidentally, the hole I made was just slightly smaller than a 10-32 locknut. Pretty confident that this wouldn’t get fielded as is, I hammered a nut into either side and bolted that bad boy in (thru the 1/4 holes I had already drilled in the chassis)
Thing worked great and we kept it for the entire season. Wasn’t until we got knocked out in semis on Galileo that I told any of my teammates how that integral part of our robot was mounted
This year, our grabber claw came back from fabrication with weirdly sized shafts (they were metric so a bit off) with threading on the ends so we just tapped four LEGO wheels and kept them there for the competition. We superglued them but they still kept coming off, so we just tightened after every match, and even lost some on the fields, but luckily we had backups
