Anyone lost thier BaneBots Carrier pins?

[StevenB]

During our last match today, we lost one side of our drivetrain, and were unable to drive around. When we took apart the BaneBots gearbox, all 5 of the pins in the carrier plate had come out of the carrier plate, so that the output shaft spun freely. This is with the new hardened carrier plates, in a 2-CIM 12:1 gearbox.
Has anyone else had this problem?

[JoshD]

I did notice that when I put the new plates in that they were really just pins stuck inside a through hole, unlike the other plate which had pins in a partial hole. Thanks for getting this out, now it ours fails I'll know what's wrong with it.

[Andrew Blair]

Banebots, in a hurry to get these new carrier plates out, had to substitute a standard pin that they could easily obtain in place of their own, longer pin. Therefore, the pins are a bit shorter. I guess the lack of engagement inside the hole is allowing the pins to back out in operation.

I suppose teams should press the pins back out and use some press-fit loc-tite to retain them. That seems like the easiest solution. Any team with an arbor press should be able to take care of it in a few minutes.

[Richard Wallace]

There was one report of this problem from a team at St. Louis. I believe the team was 525. Hopefully someone from that team will provide more details.

[Mike]

From what I heard this happened to our team (I'm a programmer, but I think this is what happened.)

We have pictures of the carrier plate somewhere...

[StevenB]

I wasn't there when it happened, but we apparently lost the pins on the other side this morning. We had been playing a lot of defense. Unfortunately, there's no good way to check for the problem without taking apart the gearbox, and when it fails, it fails completely.
We had noticed difficulty making left turns sometimes, and backing up made the problem go away. This might be a warning sign, but we need more evidence to prove it.

[Tapoore]

Originally Posted by StevenB

I wasn't there when it happened, but we apparently lost the pins on the other side this morning. We had been playing a lot of defense. Unfortunately, there's no good way to check for the problem without taking apart the gearbox, and when it fails, it fails completely.
We had noticed difficulty making left turns sometimes, and backing up made the problem go away. This might be a warning sign, but we need more evidence to prove it.

Yes. BOTH of the BB transmissions on our robot failed during the course of one regional. They failed in exactly the same way and likely cost us a qualification round. We had the second one fail on us during the QFs. Fortunately, because of good planning and an amazing display of teamwork, we were able to swap out and install an spare transmission assembly in between matches. Our drivetrain is a 6 wheel-drive using the KOP wheels with the center wheels lowered.

[jskene]

Well, I guess we won't be using these transmissions next year.

We will pull them out and rebuild them for our next 2 competitions.

Does anyone know the precise diameter of the pins?

I think if we insert a short pin into the top of the planetary gear, this may prevent the longer pin from coming out, in addition of course to putting some thread locker on the ends of the long pins.

[Robo_Coyote]

Team 1323 had one of our transmissions lock up. We were running the two CIM adapters to the kit banebot transmission with a new carrier plate and the spur gear in the center had pushed the inner carrier plate out and was making the Global Gears bind. Team 1778 in the pit next to us had this happen twice with two different Transmissions and they were only running one CIM to them. Anyone else have this problem

[Bruce Newendorp]

We had the same problem - the pins came out of the new carrier plates and one of the planet pinion gears stripped. I posted a long explantion on this Our Banebots Experience thread.

[sanddrag]

Originally Posted by Robo_Coyote

Anyone else have this problem

We had this happen in testing. Locked up so bad couldn't turn it with a 5" wheel on it. Single CIM, 40lb bot, slippery surface. Took it apart, greased, put back together, ran like butter.

[Uberbots]

Yes, it has happened to us, multiple times. Those carrier pins shoot out after less than an hour of driving on our robot- and we are simulating competition defense. This really is not good.

[JohnBoucher]

Yes.... In NJ we took them to the machine shop and had them spot welded. That seemed to hold them for the rest of the regional. I don't know if that fix will last.

[Daniel_LaFleur]

My biggest concern here is that we've replaced a predictable failure (increasing backlash until the double d fails) with an unpredictable failure (pins pulling out of the carrier plate). If this is the case we have made a bad situation worse and almost makes me want to consider keeping the weaker carrier plates.

[Elgin Clock]

Originally Posted by Mike

From what I heard this happened to our team (I'm a programmer, but I think this is what happened.)

We have pictures of the carrier plate somewhere...

I'll get them pics up tonight for all to see.
Basically in the high stress situations inside the transmissions, the pins holding the carrier plate to the gear array slipped right out of the plate. Slip fit pins anyone?

Not good.

Originally Posted by JohnBoucher

Yes.... In NJ we took them to the machine shop and had them spot welded. That seemed to hold them for the rest of the regional. I don't know if that fix will last.

That was our fix, and I'll post a pic of that as well for reference.