pic: Ungreased toughboxes!!!!

[Kyle Love]

We have four Toughboxes on our robot this year. We lubed them like every other gearbox that 1646 has used, and have had zero problems with wear such as this. There is no reasonable way that this could happen this season if they are properly set up. As I was taught in high school, a properly lubed gearbox, is a happy gear box.

[Taylor]

Originally Posted by Kyle Love

As I was taught in high school, a properly lubed gearbox, is a happy gear box.

I wonder who taught you that....

[Johnny]

Our team ran our transmission's with zero grease all of last year!
We used them again this year to practice lol. This situation must have some other variables

[Chris Fultz]

is the lexan plate part of the kit, or did you make that?

[MrForbes]

Originally Posted by Chris Fultz

is the lexan plate part of the kit, or did you make that?

Part of the kit. Didn't you at least look at the kit gearboxes?

[Smoores]

The first thing we did was machine metal plates for the backing, because last year we shattered/melted it.

[SuperBK]

This reminds me of a true story:
A farmer brought a worn-out guage wheel assembly to my uncles machine shop. The farmer turned to his own son and said "See that's what happens when you grease it too much". The son quickly responded "Oh no papa - I never greased that thing!".

[suj]

not so tough now are you toughbox

[Chris Fultz]

Originally Posted by squirrel

Part of the kit. Didn't you at least look at the kit gearboxes?

obviously not. using something different ...

[dani190]

Originally Posted by Chris Fultz

obviously not. using something different ...

sort of like not reading a manual and just throwing it out when you open the box

[cbale2000]

So THAT'S why our gearboxes keep doing that.......

[kajeevan]

Well to answer a few questions, the gearboxes ran for about 10 hours each on the playing surface using the rover wheels. In the rush to make the practice and chase (rabbit) robots the greasing completely slipped my mind and thus the result. Unfortunately this had happened all 4 of the gearboxes. On the final robot we did grease it but this was before we saw this problem. After seeing what happened I m going to go back and ultra lube it. Assembly wise I m quite sure they were aligned properly and there were no mistakes there.

[R.C.]

Originally Posted by kajeevan

Well to answer a few questions, the gearboxes ran for about 10 hours each on the playing surface using the rover wheels. In the rush to make the practice and chase (rabbit) robots the greasing completely slipped my mind and thus the result. Unfortunately this had happened all 4 of the gearboxes. On the final robot we did grease it but this was before we saw this problem. After seeing what happened I m going to go back and ultra lube it. Assembly wise I m quite sure they were aligned properly and there were no mistakes there.

Everything happens fast in FIRST and Shift happens. Have fun and hope to see you at nationals.

[Andy Brockway]

From the picture it looks like you have a custom output shaft, 3/8 hex with 3/8 bearings on both ends. Also the gear on the CIM looks like minimal to no damage. From this I would check your center distance for the final reduction. Too tight and lack of lube may be a combination that caused your failure.

[dtengineering]

Originally Posted by kajeevan

Well to answer a few questions, the gearboxes ran for about 10 hours each on the playing surface using the rover wheels. ...

I have to admit I was intially quite reluctant to believe that a lack of grease alone would cause such catastrophic failure in a Toughbox... after all, we just dab a bit of white lithium grease on there and have never had a problem. But I doubt that even our last year's gearboxes have seen ten hours of continuous driving.

I find that even with the wheels up and off the ground and just the drag of the gearbox and chains, the CIM draws just under three amps and needs to be cooled after 20 minutes or so of continuous use. With the robot on the ground and driving, I wouldn't rate the CIMs at even a 50% duty cycle. This means that based on my experience, ten hours of continuous practice driving is going to require somewhere in the neighbourhood of 20 hours at a practice facility at a minimum. I doubt we have ever had more than an hour or two of actual driving time on our toughboxes before we ship, including a 20 or 30 minute "break in" period that we give each gearbox. (Yeah, I know the gearboxes shouldn't "need" to be broken in, but we find that the drive system as a whole seems to run smoother and at a lower current draw after it has been spun around a few thousand times.)

Given that a regional involves, say, 12 two and a half minute matches (admittedly some teams have a slightly higher average...), and assuming an equal time spent practicing on the practice fields, it would be unlikely for a toughbox to see much more than an hour's use at any given competition.

So I guess what I'm getting at is that 10 hours of actual driving under load is actually a pretty good lifetime for a Toughbox, particularly one without grease. With grease, it would be reasonable to assume a lifetime greatly in excess of ten hours, making them, for all practical FRC purposes, eternal.

Thanks for posting that crucial piece of information about time to failure... I had been assuming this was a new gearbox, freshly assembled, that had failed in less than an hour of use and that just didn't seem to make sense, grease or not.

Jason