[Bruce Newendorp]

I also would like to provide my Banebot transmission experience during the build season and the first week of regional competition.

Our team decided early in the build season to use the Banebot 56 mm transmissions with 2 CIM's per side. We purchased the 2 motor kits and got the basic chassis and drive train done early giving us time to work on the tube handler, ramp and autonomous code. When the transmission problems surfaced, we considerd replacing the Banebots with AndyMark's but decided to not take the time to do it.

We are using a 4 wheel drive 38" wide X 28" long skid steer configuration with 4" Colson's on the back and 4" hard plastic wheels in front. There are 2 CIM's per side with the 12:1 reduction 56mm planetary gearbox. The output shaft has two 17 tooth sprockets and the Banebot beraring support at the end. Each drive wheel has 12 tooth sprockets.

We ran the robot a lot during testing and demonstrations before we shipped. I was monitoring the backlash and it was not bad.

We received the replacement carrier plates and spent the first two hours Thursday at the St. Louis regional reinstalling the transmisisons into the robot. We just made it to our first practice match. The robot performed well throughout the practice sessions.

Just at the end of our autonomous run during our first qualifying match on Friday, the dreaded "one side turns and the other doesn't" happend to us. The transmission output shaft rotated freely. Disassembly revealed the pins had come out of the carrier plate and one of the planet pinions had the teeth stripped off. There is no way to know for sure whether the pins came out first or the gear stripped first.

Thanks to Team 461 we had a replacement part to install. We missed one match while we made repairs. There were no more failures during qualifying or during our two rounds of finals matches but we always had that lingering concern about when the other one will fail.

One of the things we emphasize to our students is to make the robot simple and reliable. The competition site pit is not the place to be making major repairs. Unfortunately, the Banebot transmission did not hold up its part in making our robot reliable. I think the transmission design is good but it appears the manufacturing quality plan failed.

Next year we will do what it takes to have a reliable drivetrain.

I really wish this were better news for those of you who are using the Banebot transmissions.