06-04-2014 14:58

DampRobot

Re: pic: 308's Shredded mini CIM pinion

Could you give us more information on the toothcount, load, gearbox, material, supplier, runtime, lubrication, etc? We've seen similar failures of an old run of the WCP 11T pinions before, but nothing that looks quite like that.

06-04-2014 15:12

MrBydlon

Re: pic: 308's Shredded mini CIM pinion

We had an extremely similar problem this season. We competed at two Regionals for the first time this year and used the new AndyMark14U KOP chassis. We used the standard Mini-Cims with 2 CIMs on each side of the drive train.

2 gears stripped

During our last Regional, in the semifinals and finals, we basically could not drive on the right side. During the finals, we investigated and found that the 14-tooth gears that are attached to the Cims were stripped bare. Unfortunately, we had no replacements so we had to just roll with it.

Here is a link to the specific gear that we had such trouble with. CIM gear, 14 tooth

We were planning on emailing AndyMark in the future to let them know about the situation.

We attribute it to poor lubrication. We accept some responsibility on this. We should have greased them during both Regionals. We have played a combined about 45 matches in 2 Regionals (finals reached in both). However, there was a very small amount of grease provided in the package initially. So even from the start, we believe they were poorly lubricated.

Anyway, we have bought replacements for Champs and will put them in there.

06-04-2014 15:31

Ian Curtis

Re: pic: 308's Shredded mini CIM pinion

We've seen similar failures with the AndyMark kit gearboxes. We were never able to confirm how well they were initial greased, but when the gears look like that they probably aren't being greased well. The Andymark grease packets are quite small and may be applied by people who don't know how important it is. We now liberally grease them with our own big bucket of grease to ensure they don't run dry and haven't had another failure.

06-04-2014 15:48

MrBydlon

Re: pic: 308's Shredded mini CIM pinion

Quote:

Originally Posted by Ian Curtis We've seen similar failures with the AndyMark kit gearboxes. We were never able to confirm how well they were initial greased, but when the gears look like that they probably aren't being greased well. The Andymark grease packets are quite small and may be applied by people who don't know how important it is. We now liberally grease them with our own big bucket of grease to ensure they don't run dry and haven't had another failure.

06-04-2014 16:49

Chadfrom308

Re: pic: 308's Shredded mini CIM pinion

The gear was on a miniCIM on a toughbox paired with a big CIM for the drivetrain. We have 4 big CIMs and 4 mini CIMs on our drivetrain(one pair on each mecanum wheel) and this particular wheel was sounding weird. We ended up playing a few more matches on it because the time it takes to replace it.

Anyways, we opened the toughbox mini and a whole bunch of powder fell out of it. Apparently, they were not greased enough.

We used the standard Andymark grease and some of it got lost in the transition. (The toughbox was mounted directly to the chassis)

We replaced it and added as much grease as possible, and so far, no problems

06-04-2014 19:22

Iaquinto.Joe

Re: pic: 308's Shredded mini CIM pinion

And despite having one motor less on one corner, the bot still drove straight! It's all due to the fact that each encoder rate is controlled with a PID relative to the driver's inputs. Additionally, a PID is used with our current gyro angle and desired angle. The result is a robot that fights back on it's own when you apply an external force!

06-04-2014 19:29

Ben Wolsieffer

Re: pic: 308's Shredded mini CIM pinion

After seeing what happened to your gearbox, I am getting worried that the same thing could happen to us soon because I am pretty sure we only used the grease that was included with the gearboxes.

In 2010, we lost in the quarterfinals partially due to a busted gearbox.