Re: pic: Ungreased toughboxes!!!!
 

obviously not. using something different ... ;)

Re: pic: Ungreased toughboxes!!!!
 

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

Re: pic: Ungreased toughboxes!!!!
 

So THAT'S why our gearboxes keep doing that....... :ahh: :rolleyes:

Re: pic: Ungreased toughboxes!!!!
 

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.

Re: pic: Ungreased toughboxes!!!!
 

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

Re: pic: Ungreased toughboxes!!!!
 

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.

Re: pic: Ungreased toughboxes!!!!
 

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!".

Re: pic: Ungreased toughboxes!!!!
 

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

Re: pic: Ungreased toughboxes!!!!
 

Jason,

We've been really "lucky" this year to have had a lot of time to drive on the playing surface so far during build season.

We assembled the C-Base kit-frame the day we received it, and have also had our practice robot assembled for some time now. Between the two robots, we've had about 4 weeks of continuous driving. Many nights we have both robots going at the same time, and in a few days we'll have all three on the field.

The blessing is that we've had more time driving during a build season than I've ever witnessed. The drawback, is that as we play with traction control, and test over longer periods of time, failures tend to happen.

However, besides blowing a few Jaguars, and having this happen, it's been a pretty uneventful build season =)...

I guess take this as a public service announcement:

Grease your ToughBoxes!
Be nice to your Jaguars!

If there's any advice I'd give from Team 188 to other teams, it would be that.

Even though we expected the low-friction environment would be "easier" on our drive components, we've quickly found out that this may be the most taxing year we've ever witnessed on a drivetrain in FRC.

Re: pic: Ungreased toughboxes!!!!
 

well i just thought that this was all common sense, but if not. Yes grease your gear boxes, and dont be cheap!
Grease doesn't cost that much, so put lots on lol...

Re: pic: Ungreased toughboxes!!!!
 

Thanks to these guys for reminding teams that grease is good to use.

We saw this situation a few times last year at events. Each time, no grease was used. In the future, maybe we should include a little packet of grease for each gearbox.

New gears are packed up and ready to ship up to Canada tomorrow. You guys should get this shipment on Wednesday (if all goes well crossing the border).

Sincerely,
Andy Baker

Re: pic: Ungreased toughboxes!!!!
 

nice, and yea or maybe a warning sticker saying this?

anything would do...

Re: pic: Ungreased toughboxes!!!!
 

ya you sould realy grease up those tyrannies... lol

Re: pic: Ungreased toughboxes!!!!
 

My thoughts exactly...

A lot of people who build robots don't seem to know that grease is required, so anything you can do to ensure the gearboxes are greased would be a good thing. I encountered two experienced teams last year who lost gears in competition due to no grease!

Re: pic: Ungreased toughboxes!!!!
 

We just put a crap load of grease on our 5 special gearboxes, we use lithium grease if anyone wants to know and it works extremely well.