Gearboxes? Help!

[davidthefat]

Originally Posted by John

The gearbox in the pictures (look at #15) is a toughbox mini

This is an original toughbox

I don't know much about the mini, but I do know the only toughbox we have on a competition robot has ran in about 50 matches, and in every demo we have had for the last 3 1/2 years, without any problems.

Also, looking at image #11, from the wear pattern on the gear it appears that only part of the gear (the bottom half) meshed with the other gear (the top has no wear). This may be how the gearbox is designed (I don't know, I haven't looked at one closely enough, but it may be an indication that the gears are not quite the right location. Maybe missing a spacer/spacer in wrong place). I would expect this to make it wear faster, maybe someone who knows more about this than me can answer that?

Regarding that, one of the engineers that helped us take it apart (We had LocTite on the shaft... Which is a different story) mentioned that the hex shaft needed more spacing from the body. That might have been a design issue, but the hex shaft was also worn away; which allowed the gear to shift from its correct position. We will need to do more investigation to confirm that.

edit: You can seen in pictures 13 and 14 that the corners on the hex shaft have been worn away. Not sure if that is significant enough to negatively affect the gear's position. Other issue might have been a bearing that was not properly fastened that might caused the shaft to jiggle.