Removing Bosch Drill Pins - Cause of Failure?

[Mike Rozar]

Originally Posted by Pamela

Mike-

You don't need to manufacture any new parts on account of taking out the pins from the drill trannys, they run beautifully unmodified after removing the pins.

Pamela,
Thats good news. The last slide in the powerpoint pres on the FIRST site said make a new shaft, etc.

Am I correct that there are only two pins?[IMG]http://[/IMG]

Mike

[Cory]

yes, there are indeed 2 pins. Dr. Joe recommended a new shaft so that it wasnt threaded., making it easier to couple to another shaft, or mount a sprocket on.

Cory

[dlavery]

Originally Posted by Mike Rozar

Pamela,
Thats good news. The last slide in the powerpoint pres on the FIRST site said make a new shaft, etc.

Am I correct that there are only two pins?[IMG]http://[/IMG]

Mike

That PowerPoint slide set was assembled based on the assumption that you wanted to replace a major portion of the standard Bosch gearbox (ie. with a modified "Dr. Joe's Output Shaft" or similar device). If you are just removing the anti-backdrive pins, then you can stop after Slide #4.

-dave

[sanddrag]

We took ours out today. We were following the PowerPoint to the pixel and started to pull off other parts until we realized "hey, we already got the pins out, we're done!" Hehe. Anyway, it is an extremely easy procedure if you are careful. I can't wait to try them in the new "QuadraMax G2"

[Al Skierkiewicz]

Originally Posted by Mike Rozar

Does anyone know where we can get some drawings for the output shaft and the other parts you have to make when you get rid of the the back drive pins???? Please share if you can.....

We have some people to help the students machine these but maybe not design them.
Can you buy them???

Please help....

Mike,
If or when you remove the pins there is no change in the output shaft. You can still use the supplied hardware to make a drive system. The output shaft of the supplied drill tranmission has a standard drill chuck termination with a left handed thread and a locking screw just like all drills. Teams that are new to this arrangment should remember to use that locking screw and be sure it is tight before final assembly.

[Mike Rozar]

Thanks to everyone for clearing this up. We will be taking them out.

[Kevin Ray]

Ahhhhhh... THAT'S the problem!!!!

We too, had the problem of the clutch slipping after having removed the pins. Al Skierkiewicz, thank you. I was losing my mind, having rebuilt that gearbox three times.

Here's another possible issue to contend with. We had treads last year and when we wanted to dead-recon turn by stopping one tread and continuing forward with the other, the bot had so little resistance on the stopped side (no backwalk pins) that it continued to roll forward and not turn at all. We had to actually change the program from 127 to 115 on the stopped side. Is there an easier way which we overlooked?

[sanddrag]

Originally Posted by Kevin Ray

We had to actually change the program from 127 to 115 on the stopped side. Is there an easier way which we overlooked?

I'm not sure how much "stopping force" it provides but don't forget about the brake jumper on the speed control.

[Al Skierkiewicz]

Originally Posted by Kevin Ray

We had treads last year and when we wanted to dead-recon turn by stopping one tread and continuing forward with the other, the bot had so little resistance on the stopped side (no backwalk pins) that it continued to roll forward and not turn at all.

Kevin,
I think what you were up against is the extreme friction produced by tank treads. Even with the speed controllers set to brake, there is not enough force to hold back the non-moving side. You have to visualize the transfer of forces as the robot tries to turn and that the treads are trying to slide sideways as well. Tank treads are OK for certain games but they are bad if you want manuerverability and low current demand. If you look at the Innovation First site I think they still have a paper showing the currents generated by different drive systems. You can't stop a tank but you can't turn it on carpet either.

[Wetzel]

Originally Posted by sanddrag

Okay,
Is there a direct correlation between removing the pins and drill tranny failure?

From what I have seen and heard, there is the opposite. Unless you want to stay put when power is cut(like on a ramp), there isn't a reason to leave them in. So long as you put it back together properly, it should work just fine. If you havn't done it before, take 20 minutes to do it so you will see how it fits together. Its easier that way then picking things off the floor and trying to figure out what goes in first.

And wear a shirt that you don't mind if it becomes permanatly grease stained.


Wetzel