Lost Trailers

[elvis9110]

at mwr this happened a few times where they didnt get disabled. i dont know why the refs didnt immediatley disable them but at the end of the match the trailers were spilling balls out the top. not a good thing for the alliance that it happens to.

[Cory]

If the trailer falls off the robot, that should be a field fault, and the match should be replayed.

I really don't understand why the poor team that has this happen to them would get disabled. Then the alliance is penalized twice for the field breaking?

[David Brinza]

Originally Posted by Cory

If the trailer falls off the robot, that should be a field fault, and the match should be replayed.

I really don't understand why the poor team that has this happen to them would get disabled. Then the alliance is penalized twice for the field breaking?

If the team connects the trailer to their robot (which generally is the case), it's not the fields' fault (if it wasn't properly secured). If the force of a collision happens to cause a properly installed pin to come dislodged, that's just bad luck. Independent of how the trailer is lost, <G35> requires the robot to be disabled.

[IKE]

Originally Posted by Cory

If the trailer falls off the robot, that should be a field fault, and the match should be replayed.

I really don't understand why the poor team that has this happen to them would get disabled. Then the alliance is penalized twice for the field breaking?

If it is because the pin or trailer tongue broke, then I would agree. If it was because the team improperly installed the pin, then that is their own fault.

I grew up on a farm, and we never "trusted" these types of pins having them "jump" out on occasion. I never lost a hitch pin though that had a secondary cotter pin properly installed. Small bumps while undertension can put a surprizing amount of vertical force into a hitch-pin.

[Cory]

If a team installs the pin with the clip over the end of the pin, and it manages to come out, how is that their fault?

Are volunteers/refs/the FTA checking the pin prior to the match starting? Maybe they should be, and that would eliminate the problem. If they were to check, and ok it and the trailer subsequently fell off, then it's a field problem, not a team problem

[GBIT]

Originally Posted by Cory

Are volunteers/refs/the FTA checking the pin prior to the match starting? Maybe they should be, and that would eliminate the problem. If they were to check, and ok it and the trailer subsequently fell off, then it's a field problem, not a team problem

Yes at GSR they checked every robot at least once...

[s_forbes]

This doesn't sound like something that should be happening at all, and I was surprised to hear that it's such a common problem. Does anyone have a picture of the pinning system used in competition?

[Cory]

Originally Posted by s_forbes

This doesn't sound like something that should be happening at all, and I was surprised to hear that it's such a common problem. Does anyone have a picture of the pinning system used in competition?

This is a competition trailer, with the same pin they use at competition.

[gorrilla]

oh...so their not ball hitch pins like this http://www.jamestowndistributors.com...SDG-193410.jpg

[Cory]

Originally Posted by gorrilla

oh...so their not ball hitch pins like this http://www.jamestowndistributors.com...SDG-193410.jpg

Nope.

[IKE]

It may be worthwhile to bring a couple packs of these;

http://www.mcmaster.com/#92401a643/=tg77b

The actual hitch pins like this have a built in handle and a chain to keep the keeper attached.

We had pins with keepers like what we are supposed to use this year, and they would often become unsprung and then bounce out.

Anecdote. I was once hauling a manuer spreader back to our farm with one of these pins. I hit a bump, it can loose and the trailer passed me going down the hill. Not good.

[gorrilla]

Originally Posted by IKE

It may be worthwhile to bring a couple packs of these;

http://www.mcmaster.com/#92401a643/=tg77b

The actual hitch pins like this have a built in handle and a chain to keep the keeper attached.

We had pins with keepers like what we are supposed to use this year, and they would often become unsprung and then bounce out.

Anecdote. I was once hauling a manuer spreader back to our farm with one of these pins. I hit a bump, it can loose and the trailer passed me going down the hill. Not good.

On a side note:Ive had(painful) experience with the cotter pins in these breaking on my sailboat,I had two of these holding my sail-traveler-car onto the mail-sail blocks, the pin snapped and the blocks flew up, and the boom came accross and hit me square in the faceand broke the piece where the boom connects to the mast($80)


there plenty strong for the trailers though....

[GBIT]

Team 811 took some pretty huge hits at GSR and our pin never came out... They seemed like a very secure hold to me...

[metaltech]

Our 'bot lost its trailer after a hard hit from another. Worse, an alliance mate drove away from the trailer as soon as autonomous started. The killer: this was in the same match.

The other team probably had the pin miss the trailer tongue completely, the only scenario that seems likely. Our pin was installed by a pretty sharp young man, our programmer. It was also the first time he had done it (all the kids were having a try at different responsibilities, as we were so far down in the rankings). Here's what's weird: he said the pin was still in the hitch through both upper and lower holes. He said he had put the clip around the pin. I didn't see it myself, so can't verify or deny. It seems unlikely, but at the same time, I don't see how the trailer could have made it partially through the match if it hadn't been connected to begin with.

I don't know if a team can supply their own pin to be sure it's good. Pin installations weren't being checked by staff, as far as I can tell. (Two trailers off in the same match? No double-checking there.) But, I would strongly recommend you do what you can to prevent separation. This is a terrible way to kill a match. The trailer sits there like a dead duck, getting dumped on. This kind of thing should simply not happen.

mt

[Ian Curtis]

Originally Posted by Cory

If the trailer falls off the robot, that should be a field fault, and the match should be replayed.

I really don't understand why the poor team that has this happen to them would get disabled. Then the alliance is penalized twice for the field breaking?

We lost our trailer twice (once in practice, once during an actual match). Both times we had the pin secured correctly, as both myself and the operator checked it. We made the field crew aware that we had lost it twice (we were the only team to have such a problem), and they checked it for every match afterwards. We brought a pair of pliers to apply a little extra pressure up. Looking at our trailer hitch, it appears that the spring clip was getting pinched between the trailer hitch and the trailer tongue. The spring steel clip had worked it's way into our trailer hitch at least 1/8". And yes, we did pass inspection, and the trailer's bumper contacted our bumper long before the trailer tongue touched the bumper. As far as we could tell, the high speed collisions were compressing our bumpers significantly which in turn pinched the pin. We cut off our back corners, but our robot was still as wide as longbots who had no trailer troubles. Perhaps it has something to do with open center pool noodles vs. solid pool noodles?