Buggy BAG Motors

[AllenGregoryIV]

Originally Posted by Dale

Was the replacement motor thaqt failed after 100 shots a recent one from VexPro or one from an earlier batch? We're trying to decide if we can trust BAG motors fresh from VexPro or go though the pain of swapping them out.

Like you, our initial shooter wheel was going through a 3:1 transmission and failed. We replaced it with a MiniCIM which works fine but, of course, weights a lot more.

The replacement was from the beginning of build season and we had tested with it before as well, it wasn't brand new. VEX is sending us a replacement for the first one that failed. I haven't told them about the second one since it was after COB on Friday night.

[Paul Copioli]

All,

It is imperative that you send the failed, or suspect failed, motors back to us. So far we have only received 3 motors that have actually shown the failure mode described.

I need to send samples of failed motors to CCL this week to get their opinion on root cause. VEX has already formulated our opinion, but we want confirmation from CCL.

Richard is right no with the suspected failure mode as the physical evidence I have so far indicated a winding tension problem.

More importantly, the only failed motors I have are from batch 2491. I do not have any failed samples from batch 2493.

We want to get to the bottom of this as soon as possible but need failed motors back.

To answer an earlier question, no we have not had any reported failed MiniCIM motors other than a couple physically damaged during shipping. To state that all of the VEXpro motors are under suspicion is jumping to conclusions without fact. Please keep this discussion to facts only so we can get to the bottom of this.

Thanks,
Paul

[wilsonmw04]

We will send the defective motors back, however, they are currently in the bag. We will pull them in Baltimore (week 7) and send them back to you. Is there an RMA process or are we on the hook for the shipping? Either way i'm fine with it.

[dman9385]

I can confirm with Paul the all the ones 3098 had issues with not starting back up here and there are also from date code 2491.

[AdamHeard]

Originally Posted by Paul Copioli

All,

It is imperative that you send the failed, or suspect failed, motors back to us. So far we have only received 3 motors that have actually shown the failure mode described.

I need to send samples of failed motors to CCL this week to get their opinion on root cause. VEX has already formulated our opinion, but we want confirmation from CCL.

Richard is right no with the suspected failure mode as the physical evidence I have so far indicated a winding tension problem.

More importantly, the only failed motors I have are from batch 2491. I do not have any failed samples from batch 2493.

We want to get to the bottom of this as soon as possible but need failed motors back.

To answer an earlier question, no we have not had any reported failed MiniCIM motors other than a couple physically damaged during shipping. To state that all of the VEXpro motors are under suspicion is jumping to conclusions without fact. Please keep this discussion to facts only so we can get to the bottom of this.

Thanks,
Paul

Your enthusiasm and passion for investigating these issues is awesome. It really gives me a lot of faith in the product line, and the people behind it.

[Chris is me]

Originally Posted by wilsonmw04

I now think that all vex motors are suspect. Has anyone experiences these issues with the "mini cims?"

I would not jump to this conclusion. Over the course of multiple regionals, I have not seen a single mini-CIM failure on any team's robot. Weeks of extensive, high load prototyping on this motor from my team only resulted in no more "damage" than a warm motor. The mini-CIM definitely lives up to the CIM's reputation as an abusable workhorse of a motor, and I'm really glad we decided to use them this year.

[Madison]

The BAG motor we use(d) on our practice machine started exhibiting this behavior on Saturday. Our competition robot was fine as of last weekend, but a design change eliminated the use of the motor altogether, so we'll never know if it's going to fail similarly.

I'll try to get someone to remove the BAG motor from its gearbox and send it to y'all, but this is going to be a crazy week for us, so it may not happen in a useful amount of time.

[pfreivald]

Originally Posted by Madison

The BAG motor we use(d) on our practice machine started exhibiting this behavior on Saturday. Our competition robot was fine as of last weekend, but a design change eliminated the use of the motor altogether, so we'll never know if it's going to fail similarly.

I'll try to get someone to remove the BAG motor from its gearbox and send it to y'all, but this is going to be a crazy week for us, so it may not happen in a useful amount of time.

As I said, our buggy BAGs are on our competition robot, which we got permission to unbag for display purposes only at the Naples Youth Expo this past weekend... And while it wasn't "work" per se, we didn't get explicit permission to pull 'em, so we left 'em on. We'll send them to you (Paul, not Madison) post-Buckeye.

[wilsonmw04]

A quick Update.

The Bag was not in the bag. It was pulled with the shooter after NC. I have it in hand and will be sending it out Monday. Since I didn't get a reply on this thread, I did a quick search and found the RMA information for Vex. I am linking it below. Those who want to help Vex solve this problem might find it useful.

http://content.vexrobotics.com/docs/...A_Form0711.pdf

Would it be helpful if I tagged the two motors with the observed defects (they are different) or should I just throw them in a box and ship them?

[Dale]

We just swapped out our shooter's early batch of BAG motors with the latest 2493 BAG motors but sadly those are now showing the same reluctance to start on two out of three. We see it mainly on those Versaplanetaries transmissions with more internal, uneven, resistance. We've thrown in the towel on BAG motors until next season when hopefully this get's worked out. We'll be using 775s from here out.

[pfreivald]

I never heard... Is the case short problem on 775's a thing of the past?

[Dale]

Probably. It doesn't matter to us since our motors are mounted on the shooter's ABS base plate.

[Mark McLeod]

Beware that Vex posted a BAG "fix" that doesn't appear to be correct.
When the fix is applied the springs on ours become too short to work.
Vex tech support told us the fix is not official and shouldn't have been posted.

So just a warning that this probably shouldn't be attempted.
What worries me most is that the "fix" says it:

Applies to Production Batches: 2491BL, 2462BL, and 2493BL

The "fix" pdf is posted on the Vex website BAG motor page:
http://www.vexrobotics.com/vexpro/motor-controllers/217-3351.html
Under
Technical Specifications
Downloads & Docs BAG Motor Spring Modification Instructions

http://content.vexrobotics.com/vexpro/pdf/217-3351-BAG_MotorSpringModInstructions_20130411.pdf

[ttldomination]

Originally Posted by Mark McLeod

Vex tech support told us the fix is not official and shouldn't have been posted.

...wat?

- Sunny G.

[Mike Copioli]

Originally Posted by Mark McLeod

Beware that Vex posted a BAG "fix" that doesn't appear to be correct.
When the fix is applied the springs on ours become too short to work.
Vex tech support told us the fix is not official and shouldn't have been posted.

So just a warning that this probably shouldn't be attempted.
What worries me most is that the "fix" says it:


The "fix" pdf is posted on the Vex website BAG motor page:
http://www.vexrobotics.com/vexpro/motor-controllers/217-3351.html
Under
Technical Specifications
Downloads & Docs BAG Motor Spring Modification Instructions

http://content.vexrobotics.com/vexpro/pdf/217-3351-BAG_MotorSpringModInstructions_20130411.pdf

Mark we have applied the fix to all of our BAG motors without incident. We have also applied the fix to team 2337's robot. Could you post some pictures of the problem you are observing?