What hath we wrought? 2016 Horror Stories
 

After & During the 2016 season I've come across a number of horror stories of all sorts from the fields.

Teams learned how good their wiring was and how tough a field could be on robots.
FIRST learned a bit about the monsters they've brought forth by the damage to the fields.

I've heard of batteries winding up feet away from robots after a crossing. I've been at an event where a robot left the field (and the e-stop button failed).

What have you seen this past season?

Re: What hath we wrought? 2016 Horror Stories
 

I know that all the competitions I went to in North Carolina they put all the small parts from the robots that came apart in a table off the field. Also, I witnessed a robot smoking after the match ended and the robot tried to stay up for the scale.

For our team, we didn't protect our mini-cims and the end where the wires come out of popped off. I believe this happened because of the step to keep the robots on for the capture. We ended up putting tape on it to keep it together, and it still worked.

Many a time I saw the zipties pop off and lexan decorations forcefully removed from the sally port by too-wide robots.

Re: What hath we wrought? 2016 Horror Stories
 

I'm still impressed with the way this output shaft sheared at MAR Champs.

Re: What hath we wrought? 2016 Horror Stories
 

Yeah I think you witnessed us smoking after the match. Asheville was not kind to us. Our climber gearbox decided it was done after about 60 climbs so we used our backup from then until Champs. Still managed not to hit the carpet and foil the capture!

Re: What hath we wrought? 2016 Horror Stories
 

We learned that the proliferation of 3D printed parts in 2015 should not have been copied in 2016.

We broke some custom intake rollers (in all fairness, after 2 regionals and some heavy contact)

We also bent/destroyed our intake roller shaft (0.5'' steel bent at about a 10deg angle at the midpoint) during a collision with Team 179 at Champs... I think they broke too.

Oh, and the chains... so many broken chains...

Re: What hath we wrought? 2016 Horror Stories
 

It didn't happen till the off season, but we completely destroyed a ball shifter gear. Other damage includes innumerable broken chains, 3 destroyed intake plates, and a bent frame rail.

https://imgur.com/a/JLzT2

The gear on the other side hasn't lost any teeth yet but is showing a pretty bad wear pattern so we're replacing both.

Re: What hath we wrought? 2016 Horror Stories
 

Is that 1/2" hex to 3/8" hex on the same shaft? Based on the shear it looks like the step up to a larger size may have helped make the near perfect shear point.

Re: What hath we wrought? 2016 Horror Stories
 

Looks like the 5/8" step down to the 1/2" hex on the WCP Dog Shifter output shaft.

Regardless, this Step down is the exact spot to expect a failure on the part.

Re: What hath we wrought? 2016 Horror Stories
 

Gotcha - didn't see the slot at first.

Re: What hath we wrought? 2016 Horror Stories
 

Among all the carnage this years game produced, there were a couple things that made me smile, and a couple that made me cringe!
Who will ever forget the "Pole Wars"?


I witnessed a Defence attack a volunteer. I saw it roll up and smash her fingers right in front of me before I even had time to react. (Sorry, no pictures for that one. This is not the place for that.)

Auto was fascinating this year! While some teams were "grinding" out two ball Auto, others took a slightly more aggressive approach! More power, all the time! I saw more Driver's Stations on the ground this year than ever before!
I even saw one team that missed the memo that "Robots are NOT Points!"





This is where they ended up during Auto, and this is where they stayed all match.

This year's game was brutal for both Robots and the field it's self.
If you had a design flaw, this game would find it and show it to you, RIGHT IN YOUR FACE!!

Re: What hath we wrought? 2016 Horror Stories
 

Anyone who ran or helped run a competition understands the struggle of dealing with the defenses. Stronghold was cool, but it was a big logistical challenge.

As for failures, we've broken four 17t gears from the AndyMark Sonic Shifters (2 during the regular season). We have one more competition this year and hopefully we don't need any more because they appear to have been discontinued.

We also sheared a 1/2" steel drive shaft very early on in the season.

I hope we can go back to 4" or 6" wheels (aka a wheel size that were used to determine gear ratios for COTS transmissions) so that we don't keep breaking parts with unsuspected loads.

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

To add to this, we also cracked our beaver tail intake. It was so sad watching the robot drive as the intake flopped around.

Re: What hath we wrought? 2016 Horror Stories
 

One of my favorite ironies occurred at IRI this year when TechFire's motor started smoking on the field.

Re: What hath we wrought? 2016 Horror Stories
 

It probably was you guys, it seemed like your robot successfully scaled almost every single match. Your robot was an amazing one to watch and compete against. I remember that at Asheville we were playing defense against you, and your robot hit the ground very hard, at the point where most robots would break. Then, you guys fixed the robot and won the next match.

Re: What hath we wrought? 2016 Horror Stories
 

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

Re: What hath we wrought? 2016 Horror Stories
 

'Nuff said.

IIRC 2640(HOTBOTZ) had a drivetrain motor burn out during a match. Their robot was pretty good, and they fixed it quickly, but one whole side stopped working properly at DCMP. Still an amazing performance with a broken drivetrain.

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

Our active got drove upon during a match at champs, more or less had to rebuild it. Same thing happened at Minnesota State.
I chose to rebuild it for IRI, and it was a very good call because 233 more or less made a giant dent in it.

Oh and lots of chain was harmed in this season.

Not to mention 3 stripped gears in the WCP Double Reduction gearbox (we broke 3/4 that we had(got put out of commission for 10K lakes regional))

Not to mention the match at champs where we had our rear bumper ripped off our robot https://youtu.be/6FG63S24z1g?t=85

Not to mention two matches where our bottom plate ripped out and dropped our battery.

And lots of melted pneumatic tubing as we were running the 98C which gets really hot.

Honorable Mention: https://youtu.be/DDm56AZgHf8?t=73
The time we drove on the top of 2052 at MRI :D

Re: What hath we wrought? 2016 Horror Stories
 

I think we've broken almost every 3D printed part on our robot at least once

Re: What hath we wrought? 2016 Horror Stories
 

I'm surprised that nobody has mentioned the robot fire at Michigan State Champs yet.


Yeah. I could go with never seeing that again too :(

Re: What hath we wrought? 2016 Horror Stories
 

I call this match "New Drivers Vs. Intake Rivets"

https://www.youtube.com/watch?v=Ly654puHgZc

This is a good lesson about planned failure points though. If we had used steel rivets instead of aluminum rivets to hold the tubes making up our intake together, the intake would have broken further along, and in a far harder to repair place.

Re: What hath we wrought? 2016 Horror Stories
 

As you can see in the picture, 2781 flipped over, we (234) lost a bumper, and 461 dislodged a defense. I believe this all was in auto. Thank goodness, we were able to replay this match because of the field fault.

Edit: Also, all 3 of us are on the same alliance. This was at the off season event Boiler Bot Battle so correct colored bumpers were not required.

Re: What hath we wrought? 2016 Horror Stories
 

Unless those wires shorted to each other, that's probably not what was happening. Assuming everything was taped over as it should be per the rules and the inspection checklist, the loosening of your connections was increasing the resistance at those connections. Higher resistance with the same current (P=IR) means more power dissipated. More power dissipated means the main breaker heats up, and since it's a thermally tripped device, it opens faster shutting down your robot.

Either that or it's really loose and wiggly and you intermittently lose power. Even a fraction of a second will reset the RoboRIO and Radio.

It's a problem that pops up occasionally that often gets the attention of FTAs and Robot Inspectors due to the random shutdown. A bit of diligence when tightening and some lock washer (split, toothed, or other) will typically prevent such a problem. Although the extra pounding induced by the game this year may have challenged even those preventative measures.

Re: What hath we wrought? 2016 Horror Stories
 

About a week into October, the pancake on our gearbox decides to come unattached somehow. And second match at WMRI our robot's autonomous decided to go the wrong way and she ended up mounting one of the other teams' robots XD

Re: What hath we wrought? 2016 Horror Stories
 

Impressive, I don't think 125 broke any of the 3d printed parts on the bot last year. This included the entire intake roller being 3d printed.

Guess it just goes to show you that 3d printed parts aren't inherently weaker it's all in how you design and use them.

Re: What hath we wrought? 2016 Horror Stories
 

We were relatively lucky. We only blew a few pneumatic tires and stripped out the plastic VEX versahubs.

Re: What hath we wrought? 2016 Horror Stories
 

I mean, they are inherently weaker than injection molded parts - it's just a matter of if they are designed and built strong enough for the application. But your general point is right, I'm just being pedantic.

In general, this thread has many examples of design practices that are potentially fine being written off as universally bad ideas that can't work, or design concepts being blamed as the root cause of problems that they may not have been. 14 tooth pinions do not universally fail in 3 CIM gearboxes, for example, nor do plastic hubs.

If making a general rule and building very conservatively works for your team, that's great, just be sure not to give things out as general advice without a solid grasp of the "why".

Re: What hath we wrought? 2016 Horror Stories
 

You're right, the intent of "inherently weaker" was "inherently too weak". They are weaker.

Re: What hath we wrought? 2016 Horror Stories
 

Gotta have a solid frame for a game like this and for antics like these:
https://www.youtube.com/watch?v=FEKWdsOhAdY

Yes, the other team was slightly terrified we were stuck in high gear at the wrong moment without bumpers and nearly landed on them.

They also learned to keep the battery strapped in a bit better since it disconnected and flew from the robot.

We did drop to the floor once from about 4 ft from the ground during testing but I can't remember any other serious drops on the field. Most of the climbing failures just resulted in a slow and uneventful descent. I was more worried about drive components cracking than frame this year.

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

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*

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

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.:D

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

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

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

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....

Re: What hath we wrought? 2016 Horror Stories
 

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

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

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.

Re: What hath we wrought? 2016 Horror Stories
 

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!

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).

Re: What hath we wrought? 2016 Horror Stories
 

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?

Re: What hath we wrought? 2016 Horror Stories
 

It's one of three things
1) You need to tighten the bolts down more (use a wrench)
2) You need to crimp your contacts better (use proper tools)
3) The connector housings need to be replaced (this was one of our issues)

Re: What hath we wrought? 2016 Horror Stories
 

Thank you for the explanation, without that it appeared like he just thought driving into an 8” tall wall might be cool. You had the match in the bag before that, turned in your favor over all anyhow. Congratulations.

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We forgot to loctite our competition bot's gearboxes.

This lead to the horror story that was day one and early day two of North Star

The CIMs started sagging on us.

And this is where our errant design kicked in. The back of the CIMs were practically pushed right up against each other, so taking the gearbox out was not exactly the easiest thing to do. We did have our practice bot gearboxes on hand (which were loctite treated), so to save time were were going to just switch the gearboxes out for the practice bot

But this was also at the end of day one, and we played first match on day two. We were internally panicking. The swapping of gearboxes would take a long time, and we were being pushed as the pits were closing.

We left the pits with no drive gearboxes in the robot, and we had very little time before opening ceremonies on day 2. The first robots to queue are supposed to be queued up during the ceremony, but KING TeC was not there. We still had to put in the gearboxes, redo the electrical, and test to make sure everything worked.

In the latest possible time we got the robot out, but we walked out on the field not knowing if the robot was going to move.

In a stroke of luck everything worked and we had a pretty good match. The relief was beautiful.

But we were setback significantly from this problem. We didn't have time to address any of the other things we had planned to look at, so the quals matches in general ended up being underwhelming for us. We didn't show off nearly as much as we wanted to.

Re: What hath we wrought? 2016 Horror Stories
 

At champs, our team (4276) got our intake arm broken out of its stand-offs. It was hanging uselessly in our robot. Unable to score, we went to our courtyard to play defense and, long story short, tipped a robot over, earning us a red card (https://youtu.be/z25Bbz4DlkY). This was our last match of the season, we were paired with the Cheesy Poofs, and we won with 4 RPs. Because of our red card we were given no points and dropped to 50-something place (we would have been at around 20 or 30 with the points). So we went back to the pits where we started cleaning up and, once again, repairing the broken arm. Overall, our team has seen a lot more breaking happen this year than in previous years.:(

Re: What hath we wrought? 2016 Horror Stories
 

Also a very sad moment: https://youtu.be/YHDG6jRnkQw

Re: What hath we wrought? 2016 Horror Stories
 

Yeah, that was very ironic.

Re: What hath we wrought? 2016 Horror Stories
 

Er... That was my team.

https://www.youtube.com/watch?v=me6U_NBAf6g

Re: What hath we wrought? 2016 Horror Stories
 

I can confidently say you might have been the first, but you weren't the last to do that this year.

Re: What hath we wrought? 2016 Horror Stories
 

It is not the first time I have seen a robot charge into a wall but it is the first time I have seen a robot bust through. I remember the days before they put velcro on the driver stations and robots were knocking driver stations off the platform in autonomous.

Re: What hath we wrought? 2016 Horror Stories
 

Red and Blue boulders, oh my!