bosch gearbox separation
 

We had the problem a lot in low.
It starts with the fact that the mount doesn't have all of the functions of the original drill shell. The drill shell prevents the clutch end from rotating and from separating (away from the motor at the three prong bayonett connection).
The dsign of the clutch itself produces a thrust force which will drive the clutch apart from the gearbox.
We solved it by drilling holes on the existing mounts and wrapping wire around the black cone housing to hold it together.
I suspect that teams which had few or no problems were those who didn't use the misalignement coupling or those who jammed it so tight along the shaft line that the gearbox and clutch could not separate.
In any case, the blue bayonett prongs are not strong enough to do the job on their own, the mount has to help.
I hope that the designers of the motor mounts take notice and improve their design, because it was pretty nice except for that problem.

Charlie Affel, Mentor, 487

I know that I personally did not modify those drill transmissions one bit. The only two problems we had with them were caused by:
a)my stupidity
b)my cluelessness
Besides that they worked flawlessly. Though there was an odd problem with the clutch were it was working while we were testing and it mysteriously turned so that it was in screwdriver mode during our first test run between then and shipping.

bosh drill trans
 

What was your choice of speeds? High or Low?
What was you final drive ratio?
How big are your wheels?
For us it was low gear, 2 to 1 reduction using the FIRST helical gearing and 10" very grippy skyway wheels.

CA

problems with drill gearboxes?????
 

we have seen no problems at all with the drill gearboxes....the onlything that's prolly killing you is those motor mounts. there is no way they can withstand the amount of torque most team put on them. we simply avoided the plastic and made our own aluminum....we also removed the clutch collar and locked the clutch. next year look into machining your own mounts.

Transmission
 

I think we, team 812 had the worse thing happening with our transmission on both sides. Umm, we stripped the left hand screw twice, the mount for the transmission caused a lot of vibration which evenventually knocked the chains out of alignment, the clips fell out 3 times until we used zip ties, the custom fabricated hub for the transmission of ours got the threads meout of alignment because of pressure and that caused the hub to be completely slanted and we found out that the threads were completely ripped. We ended up going back to cmall parts about 2 times for 2 transmissions. As you can see we had every single problem out there, mainly due to our driver hitting the wall at high impact so many times.

I think these transmissions have been wonderful. It seems as if most of the issues are coming from teams that are using the supplied FIRST tranny. We just tappedsome flexible lovejoy connectors, screwed em in, and put sprockets on another shaft that drives the wheels. We have never had any trouble with them. The thing we have had trouble with is brushes falling out/breaking. The brushes are incredibly delicate compared to last years drill motors, and very exposed.

Cory

The only problem we have ever had was that in soldering on new wires during the build we cracked the thin part of the black plastic endbell that holds the brush hood on the rear of the motor. We just pressed a little too hard with the soldering iron. Anyway, we epoxied it back together and I'll bet that is is stronger than ever. We mounted that motor in such a way that the wire actually pushes together on that piece so it would never have any problems. We also made little mounts for our large #8 wire to the motors to relieve some of the stress on the terminals and endbell. So, besides that minor mishap, the motors have been trouble free. We did not modify them at all and use standard zip ties to hold thm in high gear.

All the drill problems come from teams who drop them, install them incorrectly, or modify them.

Nothing is more true in the case of the drill motors than the saying, "If it ain't broke, don't fix it."

today while showing our robot to a group of third graders something happened to the transmission for the left drill motor and we could drive the left side anymore backwards, this also happened in St. louis to the right drill motor and we had to swap out the transmission. we have made absoultly no changes to it either aside from locking it into lower gear with a zip tie. we are a high torx robot and can push most others around. could this be part of the problem?

I would guess that you didnt remove the drive pins, one or both sheared, and they will glide one way but wedge when you go the other way. Thats what happened to us.

Good Luck