What hath we wrought? 2016 Horror Stories

[fargus111111111]

I'm slightly surprised BillFred has't posted his sign from Palmetto in this thread, for a while the CDF was not an option, they were ALL broken! Granted this was before HQ had the metal reinforcements put in them, but still, 1/2 inch polycarb is pretty hard to break. Other stories of motors releasing their magic smoke, I'm sure there are plenty, as well as connection losses because of wires jarring loose, I know we had that problem in the finals in Palmetto. We also had a minor issue with our 3d printed drive pullys, we used an elongated version of the rhino track this year with some Breco-flex belts and originally we 3d printed pulleys for them to run on, needless to say, those didn't make it through one competition, we replaced the 4 corners with metal pulleys for our second regional.

[scca229]

Originally Posted by troy_dietz

9330 during their second semifinals match at BeachBlitz.

We almost scored a low goal like this, but the right side of the intake hit the main breaker. We were able to aim reasonably well with the turret bolted back on for the finals, but that robot won't be scoring any time soon.

The best part about this one was that the breaker was hit when the bot wasn't on the batter. It was pushed on just before the end of the match.

*As an aside, earlier in the competition we also got to see first-hand 330's main bot do a recreation of the Einstein gymnastics after flopping on their back. That was cool to see in person*

[BrendanB]

1058's tougher times this year:

Reading Match 1

Our climber is a double linkage designed so the gas shocks keep it down before a piston pushes them past the center point so they take over and extend up. We some drop tests and drive tests over defenses and it worked fine. First match in autonomous the climber extends upwards after driving over the rockwall and we all had this moment of, "This is very bad". The root cause was a knot of surgical tubing was preventing the assembly from collapsing all the way. We adjusted the knot, added a small strip of painters tape as a temporary fix, and added a piston lock as a permament solution for the rest of the season. We also destroyed about 8 halves of the AM 6" Pnuematic Tire Hubs over the course of the event. We had plenty of spares but we knew we had to start making our own hubs asap. This meant our addition of a shooter was delayed by an event so we were testing and tuning it during the New England Championship.

Any match on Caver

Our robot had about 80 official matches on it by the time St. Louis rolled around. We added our working shooter at the previous event and made a better intake for Champs hoping to see our cycling improve. Little did we know most of our matches there had some major failure or breakdown leaving us disabled or limping on the field. The plates holding our gearboxes had bent into the robot so we threw the gearbox chains the first match. Our climber had be used so much that after we scaled the tower the hook snapped and sent the robot the ground. We sheared the bolts on our metal hubs. Our pnuematic system acted funny so one or two shots barely lifted the ball out of the robot. We had some miscommunication on changing some autonomous modes (completely my fault) so we didn't fully cross some defenses. We had some odd electrical problems leading to brownouts. It was a rough event knowing we had potential to do so much more but it was the point where Stronghold was getting the better of our robot.

Mainely Spirit

We had some odd pnuematics issues later in the day where near the end of each match we had no air left in our system but once we enabled in the pit the compressor turned on immediately. When we got home we diagnosed the compressor was shot. After the fourth or fifth cycle of needing air it refused to turn on even with a signal from the PCM.

Stronghold is the hardest game I've played and I'm amazed how well our machine has held up over 136 matches plus practice and demos.

[Ringo5tarr]

Of course, how could I forget about our wonderful match in the Iowa regional?

First, the buildup, so we had a camera on our robot, but it was A.) not implemented, and B.) Worthless even if it was because our flywheel didn't have a working encoder until last month (When I eventually became electrical lead).
So it was removed middle of the regional.

Turned out that caused something to go wrong in the teleop programming, so after a successful breach of some static defense, teleop starts and the robot turns, and keeps turning, in a circle, because it was going in donuts and left a mark on the field that was not removed by closing ceremonies.

Fun fact: There is no full video of that match, anywhere. There is video of the robot on it's own going in donuts, but there is not any of the full match.

[OccamzRazor]

Where was that video from this season of the robot at a scrimmage blasting down the field wall and going into a crowd? That looked pretty intense too. Nobody got hurt thanks to some nice dodging skills but that could have gone badly.

[klink135]

During a practice run, our autonomous decided to drop out intake, (Which also functioned as our obstacle manipulator.), and run over it. The 1/8" aluminum was bent and we lost a mini cim as the wires were pulled out of it.

[EmileH]

Originally Posted by BrendanB

1058's tougher times this year:

Mainely Spirit

We had some odd pnuematics issues later in the day where near the end of each match we had no air left in our system but once we enabled in the pit the compressor turned on immediately. When we got home we diagnosed the compressor was shot. After the fourth or fifth cycle of needing air it refused to turn on even with a signal from the PCM.

Stronghold is the hardest game I've played and I'm amazed how well our machine has held up over 136 matches plus practice and demos.

And how could we forget at Mainely Spirit when our practice robot, 8501/1056 sheared one of our gearbox output shafts in our second to last qualification match. Because of this we epoxied the shaft back together and had to sit out our last qualification match while we waited for the shaft to dry. We ended up still being the #7 alliance captain with 5687 and 910 (319's practice robot's drivebase) and making it to semifinals, beating the #2 seed with 319 and 133, two crazy powerful robots despite numerous electrical faults. We tacked those up to a loose PCM power cable that shorted out every match, eventually burning up the 20 amp PDP fuse that powered the VRM, and subsequently, the radio.

[Dwight_2]

Originally Posted by codedr

I learned that if the battery cables can be rocked back and forth at the battery or at breaker, they are too loose and will cause high current draws that shutdown the robot.
Same for the wires between the breaker and the power distribution board.

Add the bouncing over defenses, robot on robot contact, and loose power connectors to the radio either at the barrel plug or at the pdp and you get a dead robot.

If you can pull wires out of the pdp wago connector they are too loose.

Our team ran into the same problem and we didn't even think to check the wires until the end of the regional.

[jkelleyrtp]

We don't have any pictures, but during our first district event, the casing for one of our drive CIMs decided to disconnect from the shaft face and internals. There was about an inch of exposed CIM innards and the motor had a hard time functioning. We were unable to remove the CIM during competition and ended up using the largest C clamp we could possibly find to keep the casing attached to the face and gearbox.

[Dwight_2]

Lol Our Team (5842 Royal Robotics) Used 2 100 lb pressurized gas shocks like those found in cars to hold a hood or tailgate up, for our scaling mechanism. Unfortunately however we never got to scale in a match with these.

At the South Florida Regional last year we were using our new amazing "safe" way to torque out the shock till they locked in the match starting position when something happened.... ill put it short. "Do not over extend gas shocks!"

The end of the 100lb shock shot out right in the direction of where one of our students had just been standing where it ricocheted of a steel knight helmet ( leaving in a sense a bullet ricochet mark) and shot through another pit putting a hole in their team toolbox lid and the disappearing forever.

We now know if FRC does not allow gas shocks in the 2017 season we were the reason why....

[dirtbikerxz]

Originally Posted by Dwight_2

The end of the 100lb shock shot out right in the direction of where one of our students had just been standing where it ricocheted of a steel knight helmet ( leaving in a sense a bullet ricochet mark) and shot through another pit putting a hole in their team toolbox lid and the disappearing forever..

Well........... that sounds just a bit dangerous. Thank god no one was hit.

[adciv]

So Semi-Finals at Rumble in the Roads, there were two new custom defenses to replace the portcullis, a triangle shaped rock wall and a one way ramp. Our driver thought the ramp was the triangle and....broke the ramp away from the defenses inducing a field fault.

[pfreivald]

We shredded the aluminum gears in a pair of WCP/VexPro dog shifters--reduced the teeth down to nubs over the course of the Tech Valley regional; we had spares from our practice robot (that had been experiencing the same problem but slower) but we didn't have the time to swap them out.

We'd have gotten into the semifinals had we been able to drive ten more feet (an easy breach for +25 points), but instead our motors spun and our robot went nowhere.

...we then had three days to build new gearboxes with custom faceplates as part of withholding--went with AM Toughboxes modified for three CIMs, and had to drill lots and lots of holes in the steel gears to make weight for FLR.

On a side note, our bot performed very well but we couldn't win a game for losing--if we scored 108, our opponents got 113. If we got 75, they got 79, etc. We took the same robot and drivers to the Ra Cha Cha Ruckus, our bot performed every bit as well as it did the prior spring, and did great.

[Oblarg]

449's Great Escape this year is probably going to stick with me forever - I'd never before seen a robot leave the field of play, and probably never will again. Make sure those e-stop switches are functional!

Originally Posted by TAlholm

Don't use a 14t gear in a 3 cim gearbox.

We destroyed one of these, too, but then we replaced them with the steel versions and had no additional problems. 8'' pneumatic tires, geared to ~10fps (don't recall precise ratio).

[TacoTheCat]

Originally Posted by codedr

I learned that if the battery cables can be rocked back and forth at the battery or at breaker, they are too loose and will cause high current draws that shutdown the robot.

Wow, we had the same problem over here, except it didn't pop up until after the season. We discovered that if the robot dropped hard enough, it would shut down. After a little bit of percussive maintenance (aka we pushed the wire back and forth for a while) we found that if you move the main power cables around enough, the robot shuts down.

I wonder if there is a good fix for this? Securing down cables a certain way, or creating more secure connections between them?