Nightmare Repairs At Competition

[TikiTech]

2011, Logo Motion, was our rookie year. At the time we had, two mentors with not much machining ability, equipment, work location or experience in large scale robotics. We have done underwater robotics (MATE) the year before which was our first year as a robotics team. Our under water robot was made out of PVC so custom metal fabricating was never even considered. After building our KOP frame and getting the drive train running, which took more time then we ever imagined. Not having a programming mentor, we all had to learn Labview together as best as we could which added more delays. We then moved on to the scoring arm. With a very limited budget, we had to make the Robotics Organizing Committee and Ace Hardware’s generous grant go as far as possible. Thanks ROC and ACE! Most of which we had to reserve for travel and accommodation expenses. With extremely limited machining capability here on the big island of Hawaii we had to resort to out of the box manufacturing and parts supplies. We ended up stripping parts from cars at the schools auto shop program to create our scoring system. This helped us gain our third mentor. We recruited the teacher from the auto tech class, more like he recruited himself. We ended up using a flywheel as our rotational arm base and cut out window motors from car doors to actuate our lift and claw. We ran out of time and we were not able to tackle the pole climbing mini robot. Since this was our first time we figured that what we had finished was going to have to be good enough.

At the first day of competition during inspection we were informed that the window motors we used on our claw and lift system were not legal. We had to remove the offending motors and compete without them. Over the course of two days we were able to adapt some donated motors, from a generous FRC pit volunteer, who just so happened to have a few. I sure thought that was odd at the time.

During the first day, practice matches, and most of the second day, qualifications, the pit crew with our new auto tech mentor rebuilt the claw and lift system to fit the new motors. Thankfully there was an onsite machine shop that made a world of difference! Thanks for being there, the BAE machine shop workers were exceptional. We were able to have a functioning scoring system for our last 3 matches and were able to actually score.
What a relief!

During most of the competition we had no other option but to play defense. And play it well we must of.
We were selected on the third pick by the first seed alliance.
We went on to receive the General Motors Industrial Design Award and the Hawaii Regional Tournament Champions!

So much help was offered and given that I cannot express our thanks enough.
FRC is such a great community to be part of.

Not quite as nightmarish as 801 & 1502 this year. But to us, as the small fish rookie team in the big pond of FIRST, we sure thought it was.

Of course the next year the window motors we used we added as legal motors, even with coupons to get from local auto recyclers.

Go figure….

[Billfred]

Psh, amateurs. Try nightmare repairs of the competition.

[Koko Ed]

Originally Posted by Billfred

Psh, amateurs. Try nightmare repairs of the competition.

That one had three year's worth of nightmares.

[techkid86]

The repair I remember making best is not mechanical but programming.

Our team came in on day two of competition and we realized we were not getting feedback from our tachometer on the shooter wheels. We frantically replaced the tach, only to realize it we merely unplugged... Imagine the despair we programmers faced when we realized the PID loops we worked on suddenly became untuned! About 1000 RPM short of target speed....

No sooner did we come to realize this, but we were on the field again, so running down the pits with the robot on a cart and a laptop in hand, we recalibrated PID well enough for our autonomous to work.

But it does not stop there, oh no! In the first finals match, we were hit hard enough for the tach to shift, and low and behold, the values change again!

Lesson learned.... Never.... Remove.... the tach.... again.... lol

[mathking]

I think my favorite repair story was from 2004. A key piece on our really cool but vastly too large and over-engineered arm broke while competing at the Championships. After a heroically fast trip by one of our college mentors to McMaster-Carr in Atlanta, we managed to get the replacement part we needed and installed. As we were heading out to the field to complete we noticed we were missing a nut. One of the mentors pulled the gum out of her mouth and stuck on the end of the bolt, and we made it out for the match.

...in the match, we drove forward for about 2-3 seconds, hit a ball and flipped the robot over on its back. Good times.

[Zuelu562]

My Junior year (2010, Breakaway) with (now defunct) 562, we had a rack and pinion system to load our shooter. The pinion was pushed into place via pneumatics, and when released it would fire. After a match, we came back to the pit to find that the rack had actually split in half!

A quick run to the machine shop and it was welded like new. Quite literally, if we didn't have the rack we would have been outside of the frame (ever so barely) and we would have had to not participate in the match. It was quite scary for a student who spent most of his time running around in a bulldog suit.

[jwfoss]

This year at the WPI regional 2168 was going through some rather serious issues with the motor/gearbox setup for their arm assembly. After struggling with this through Thursday and Friday the team made the choice (Friday night after dinner) to completely remove the motor drive and switch to a single pneumatic cylinder to achieve, at a minimum, a stored position and a position required to launch discs in autonomous.

Unfortunately this meant that we spent all morning on Saturday making the changes and dialing in a functional 3 disc autonomous. The parts were supplied by FRC558, hence the use of purple tubing if anyone saw the change. We barely made it out for our last qualification round.

Throughout the regional we had been focusing on defensive driving, and being in picking position at the end of qualification matches came as a surprise. For eliminations we had dialed in the autonomous well enough and it allowed us to support our alliance with some points. We were fortunate enough to assemble a strong alliance based on defensive and smart strategy that ultimately led to the teams first regional win.

[robochick1319]

Originally Posted by Taylor

2006 Boilermaker Regional, 1319 had a small drive base and the top shooter was on a full turret. Either at the end of qualifications or in the first elimination match, they got smacked and the top 2/3 of their robot breaks off. Like dragging behind them.
First elimination match after that, they come out with just a drive base and play awesome defense. I think they won that match.
Soon after, everything's back, working perfectly, Regional Champions. Safety Award. Spirit Award.

That was so long ago! So long ago that this mentor was actually a sophomore in high school.

It happened in a qualifying match just before lunch. Our robot ran off in auto and crashed into the ramp used for climbing at the end of the match. We hit it head on at full speed and the rest was a disaster. The whole top section split off and lay a foot away from the base. We watched helplessly as other robots had to run over and around the "guts" (i.e. wires, cords, etc.) that spilled out on the floor.

We worked through lunch and sent the base out the next match to do defense and climb the ramp for extra points. Then we added a beefed up scoring section on top and kept going. We were picked for the winning alliance and the worst day I've ever seen in FIRST led to my best FIRST experience.

This was the most inspirational moment of my FIRST experience. It taught me something vital to this program: you can cry (I did), you can be discouraged, you can think it's all over but you have to keep going. You paid all this money, traveled all this way, and worked so hard for that robot so you owe it to yourself, to your team, and your machine to see it through to the end.

The worst case scenario is your robot completely splits in half. But then again, you could always win the whole dang regional. You never know, so never quit.

[JaneYoung]

Originally Posted by Billfred

Psh, amateurs. Try nightmare repairs of the competition.

That was awful. I broke out in hives and chewed off all my nails - here in Austin, following the news on CD.

It was awful but so incredibly inspiring. Much like many of these nightmare experiences turn out to be. Because of the spirit of FIRST.

Edit: And actually, the events of this Mission Mayhem, and the way in which the teams and volunteers worked together to make the competition happen, were so inspiring that I decided that I had to travel to Florida and attend Mission Mayhem and support it in some small way. And I did. And it was so much fun! I learned a lot from this off-season on the two occasions that I made the trip.

Jane

[AlexH]

Originally Posted by pmangels17

At Duel on the Delaware (Fantastic Off-Season hosted by 365), we were #1 seed. We selected 341 as our first pick, and 1640 as our second. Then, in the semifinals, the giant lazy susan bearing we used on our turret snapped. The turret smashed onto the ground as we crossed the bump on the field. However, with the help of our great partners, and a six minute tme-out, we managed to get enough zip ties (approximately 40 normal size and 10 ludicrously large) onto the turret to hold it in place. It didn't spin for the rest of the day, but it worked in auton and for scoring, and we wound up winning.

Moral of the story: If you don't carry about 300 14 inch zip ties, you might not be prepared for your next inevitable breakdown.
Side note: 14 inch zip ties can be used for a number of things, including wiring organization, air tank mounting, turret repair, and mounting/securing almost any part on your robot.

[Peter Matteson]

In 2010 at the championship in our second to last match on Friday we fell off the bar when our climbing cable crimp failed.

We had to rebuild half our articulating drivetrain in 70 minutes between matches to get back out for the last match of the day. We knew we needed to prove to everyone our robot was functional before pick lists were made that evening. We had most of the inspectors in the division and a couple of nearby teams watching the whole ordeal because they couldn't believe that we had planned for this, had the parts ready and actually pulled it off.

Our plan worked we were back together and played our last match. The event effect divisional picking in our favor allowing this to happen...
http://www.chiefdelphi.com/media/photos/35698

I have never been prouder of our students than that day because of how they handled this situation. Our mechanical team in the pits knew what they had to do and did it no griping no issues, just get it done as fast as we can.

[KrazyCarl92]

In 2011 our team used a crab drive from 221 robotic systems for our drive train. It was set up with a window motor steering all 4 modules together, but the window motor was overheating frequently at both of our regional competitions. This led to the thermal switch in the window motor tripping and our modules would stop steering as a result. At Connecticut we ended up switching out one of our modules for a spare, thinking that perhaps the axial shaft of the module was too "beaten up" (it appeared fairly marred as compared to what we expected). This turned out to be the wrong explanation, but we left the module in anyway since nothing had changed for better or worse.

Upon returning back home, we noticed a thin ring of metal that appeared shaven on the bottom plate of the swerve module. We then reasoned that the likely reason for the window motor issues was this rubbing between the bottom plate of the swerve modules and the bottom of the frame. We came up with a plan for how to deal with the issue if this was in fact the problem at Championship, since not being able to drive would be the worst thing that could happen. We gathered thrust bearings and material for spacers to be machined once we arrived if we found this was the issue.

On Wednesday night at Championships, we send in our five people: me, our pit mentor, our driver, a programmer, and the programming mentor. We used a piece of paper to see if the pieces of metal that we suspected to be rubbing were. 3 out of the 4 modules had the issue, so we had to add thrust bearings in the axle shafts, get the bronze bushings that the snap rings sat on turned down, and have several delrin spacers machined to the proper height. In 3 hours we ripped apart the entire drive train, got the machine shop to precision machine 20 parts for us, put the drive train back together, then ran some systems test. The drive train worked beautifully for the rest of the competition, and had our autonomous worked or a button on our controller (of course the all important minibot deployment button) not failed, we may have been selected for eliminations.

The best part was returning to the hotel and reporting back to the team what we had accomplished. One of the kids said completely seriously, "You mean you ONLY got the drive train fixed!?!?"

[Karibou]

West Michigan District 2011, we destroyed our drivetrain.

One of the bolts in the drivetrain came loose during a match, and the wheels on that side stopped turning. The drivers kept driving on it because they had no way of knowing if it was an electrical, code, or mechanical problem. I didn't see the match because I was cleaning the pit, but when they brought the robot back after the match, I nearly cried.



Unfortunately, this is the best picture I have. You can't see the full extent of the damage, which is several chunks/teeth missing. I think there was some damage to the chain and maybe the axle it was on, but I don't remember - I wish that in our state of panic, we would have thought to get a picture. It was bad. That sprocket was on the center axle and was welded to a hub with another sprocket to form a sandwich. We sent the sandwich and a new sprocket with a mentor allllll the way to the machine shop on the other side of campus to be welded and worked on cleaning all the metal shavings out of the robot and fixing other problems (it turns out that 24V valves in your pneumatics won't work too well) while waiting for it to come back.

Mentor comes back with the destroyed sprocket (IIRC it wasn't bent that badly before sending it there, that was just a result of getting it off of the sandwich) and the new sandwich...which was still not usable. Apparently the welding machine jumped and the result was a tooth that was completely missing and some other tooth deformation. Sent it back to see if anything else could be done, and asked frantically through the pits to see if anyone else had a spare sprocket that we could have. We found one, and decided to drill some holes in our only spare hub and bolt everything together. Ten minutes of ratcheting and two sore wrists later, we had a sandwich that was usable.

It was by no means the best fix, but we had already missed several matches and our next one was in a few minutes. We made it out to the field literally just in time to play for our last match of the day.

-----
Not a nightmare repair at the competition, but definitely a pain in the everything:
http://www.chiefdelphi.com/media/photos/35270
See that bent corner? Having to attempt to straighten it after every match that we moved in was the bane of my existence that year. That robot was all about poor design choices, and the frame was one of them.

[Madison]

This is a picture in the middle of the repair. The 'before' -- which I don't have a picture of, unfortunately -- was pretty terrible.

We collided with 360 at full-speed midfield. Our frame, which wasn't designed to play the kind of defense we ended up playing in Portland because of a too-complicated collection system, completely collapsed. The front cross member bent inward as far as the intake roller and split in half at one of its rivet holes. The left-side frame rails collapsed as well. There are ripples in the flanges along the entire length of the left-side of the robot.

The rear-mounted gearbox and final gearing stage were knocked wildly out of alignment. The gear mesh distance was busted up and destroyed the teeth on the final gear attached to our wheel. None of the wheels remain planar with one another.

http://www.youtube.com/watch?v=r_OZi...ature=youtu.be at about 2:35.

We fixed it with a hammer and by riveting some aluminum angle along the front edge of the robot to keep everything square. The drive gearing remained mostly broken for the rest of the event; we were able to adjust it before each match so we could drive, but it'd go bad by the end.

We're replacing some of the frame parts at our event this weekend and replacing the gear stage with another chain and sprocket stage. We've also rebuilt our entire frisbee collection, storage and shooting system.

[Christopher149]

Some of this will be nightmare repairs, and some will be just nightmare problems. As a caution, this might be kind of long.

2009 - Troy District:

• Get hit by a robot at some point, breaks ball collection, add protective metal bar in front of replacement (nightmare is that it was held with zipties), zipties slip in quarterfinals, sole reason we don't advance to semis .

2011 - West Michigan District?:

• Try hanging a tube, I think in autonomous, and we managed to get our robot's lift jammed to the hooks. That was interesting to remove from the field, especially as I think the window motor thermal lock probably tripped.

2012 - Traverse City District:

• Robot falls over from bridge, bends lots of things, but we weren't using them, so they just get taken off.

2013 - Traverse City District:

• It is the semifinals, and if I recall correctly, we were unable to shoot discs our first match. After metaphorically banging my head against the wall for a few moments, I realize that its victor isn't powered and the WAGO connection has come out. We take a time out and set to putting it back in (even though we got it done in enough time [read: almost to the second] that we didn't really need it, but a time out once called isn't easily rescinded). Able to shoot that second match, but our competition beats us and goes on to win the whole thing.

2013 - St. Joseph District:

• It is Thursday, and we wonder why the shooter isn't working, after having little mechanical difficulty with the shooter at TC. We determine that the gearbox (bought this year!) is slipping under load when trying to shoot, meaning the arm cannot move. We finally determine that a gearmotor from spare parts will work, and get it put on for Friday.
• It is Friday, so many things go wrong all day, but no nightmare repairs (mostly small, annoying ones). The worst was why we were having serious communication issues. I was told it was the cRIO rebooting (and so tried a bunch of fixes to secure its power, which kept coming loose). Prior to one qualification match I found that the positive line to the cRIO has come out, and as we didn't have a small-enough screwdriver with us, someone had to run and get one. This time, we got it done in time for the match. On the practice field at the end of the day, we find that the main comms issue (or possibly another) is that the dLink is rebooting, and that issue was fixed with a single ziptie )
• Saturday went really well, aside from heavy defense...

PS Why does this year seem to have more nightmares, even though we did better? It also seems to have more repairs than outright removals .