08-02-2009 19:10

ironbears

Re: pic: Ungreased toughboxes!!!!

what happened there? how long were those running? that much steel dust is rediculous. was it assembled correctly?

08-02-2009 19:13

meastman

Re: pic: Ungreased toughboxes!!!!

Why didn't you grease them?

08-02-2009 19:29

vivek16

Re: pic: Ungreased toughboxes!!!!

Yeah... I'm adding grease to ours Monday.

I'm also wondering what kind of conditions would make them that bad.

-Vivek

08-02-2009 19:34

thefro526

Re: pic: Ungreased toughboxes!!!!

I would also like to know why they weren't greased. I think the lack of grease may not have been entirely to blame for the damage to the gears but it could have accelerated the process. Wasn't the transmission incredibly loud without any grease in it?

08-02-2009 19:55

Bandgeek80001

Re: pic: Ungreased toughboxes!!!!

We've already greased ours once, but I think we'll do it again after seeing that...

08-02-2009 20:19

Kyle Love

Re: pic: Ungreased toughboxes!!!!

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.

08-02-2009 20:21

R.C.

Re: pic: Ungreased toughboxes!!!!

I think we'll do it also, sell the powder I say

08-02-2009 20:40

Taylor

Re: pic: Ungreased toughboxes!!!!

I wonder who taught you that....

08-02-2009 20:49

Johnny

Re: pic: Ungreased toughboxes!!!!

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

08-02-2009 20:55

Chris Fultz

Re: pic: Ungreased toughboxes!!!!

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

08-02-2009 20:56

seraphim33

Re: pic: Ungreased toughboxes!!!!

i second that

08-02-2009 21:15

dani190

Re: pic: Ungreased toughboxes!!!!

no you just got very very lucky...

Using these gear boxes without grease is just plain stupid... Never run them without grease, they are rotating at 5000 RPM or there abouts... You NEED grease. No wonder so many teams are seeing gears grinding to nothing, when you have no grease thats what will happen...

08-02-2009 21:29

MrForbes

Re: pic: Ungreased toughboxes!!!!

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

08-02-2009 21:32

Smoores

Re: pic: Ungreased toughboxes!!!!

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

08-02-2009 21:37

Chris Fultz

Re: pic: Ungreased toughboxes!!!!

obviously not. using something different ...

08-02-2009 21:38

dani190

Re: pic: Ungreased toughboxes!!!!

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

08-02-2009 22:43

cbale2000

Re: pic: Ungreased toughboxes!!!!

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

08-02-2009 23:47

kajeevan

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.

08-02-2009 23:54

R.C.

Re: pic: Ungreased toughboxes!!!!

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

09-02-2009 09:32

Andy Brockway

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.

09-02-2009 12:24

SuperBK

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!".

09-02-2009 17:27

dtengineering

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

09-02-2009 18:25

Mr. Lim

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.

09-02-2009 21:36

dani190

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...

09-02-2009 22:49

Andy Baker

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

09-02-2009 22:52

dani190

Re: pic: Ungreased toughboxes!!!!

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

anything would do...

09-02-2009 23:20

alex1699

Re: pic: Ungreased toughboxes!!!!

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

09-02-2009 23:32

MrForbes

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!

10-02-2009 00:33

R.C.

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.

10-02-2009 02:13

dtengineering

Re: pic: Ungreased toughboxes!!!!

Well, we hope to follow your lead, even though we have yet to officially drive our full robot. Our robot has been built entirely in detachable modules that bolt on and off the frame. Two drive modules, a control module, and a ball handling module. The goal was to get it so that two drive modules and the control module would come in under 40 pounds. Right now we're at 46 pounds.

If we can shave six pounds off of there (shouldn't be hard... we'll just ship the CIMs and toughbox gears, and replace them with spares off last year's machine for practicing) then we should be able to get some similarly crazy practice driving time in, too, as we have five or so weeks between ship date and Seattle.

I really hope that if we blow any components that it will be in practice... competition is sufficiently intense when everything is working well!

Good luck, and thanks for highlighting the grease issue.

Jason

12-02-2009 23:00

DGrohnke1023

Re: pic: Ungreased toughboxes!!!!

That gear looks strangly familar.

http://www.chiefdelphi.com/media/photos/26520

We ran the 06 season with no grease, and had the same problem postseason. Our excuse was they didn't tell us to grease them in the assembly video. But, no one caught it all year. We grease our gearboxes now.

15-02-2009 22:49

keehun

Re: pic: Ungreased toughboxes!!!!

Wow, just happened to us... Thankfully it didn't happen at the competition..

keehun
Team 2502

15-02-2009 23:06

dani190

Re: pic: Ungreased toughboxes!!!!

no grease?

16-02-2009 10:58

Trent B

Re: pic: Ungreased toughboxes!!!!

Yep, and evidently it was a bad assumption to make that they would grease em... (says the electrical guy)

16-02-2009 11:18

Re: pic: Ungreased toughboxes!!!!

This would have happened to us at competition if it hadn't been for this thread. I saw this and called a few guys over to check out the picture. After the "Oh dang!"-s subsided, I asked the guys that put them together, "Uh, we greased our toughboxes, right?" Nobody answered, which was soon follow by everyone rushing to the shop to take apart both transmissions and lube 'em up

16-02-2009 11:26

dani190

Re: pic: Ungreased toughboxes!!!!

lol...

16-02-2009 11:29

suj

Re: pic: Ungreased toughboxes!!!!

not so tough now are you toughbox