Re: Buggy BAG Motors
 

Agreed. We found a metric allen wrench that seems to fit better than the recommended standard allen wrench size. I forget the sizes now. We wound up rounding out a couple of set screws until we got the hang of it. If there was one improvement I would recommend to the VersaPlanetaries it would be to simply drop a few spare set screws in the bag of small parts.

BTW: We had 3 "bad" BAG motors that developed the issues described in this thread. I contacted Paul as requested and they are send out replacements right away. In the mean time they emailed me an overnight shipping label and I have shipped them back our 3 "bad" BAG motors for testing. Hopefully this will provide some insight into the problem. I can't say enough good things about VexPro and the IFI guys customer service and how they are handling this issue. Thanks guys!

Re: Buggy BAG Motors
 

For all applications that use Allen keys, I personally suggest these:

http://www.mcmaster.com/#high-torque-hex-keys

They are only marginally more expensive than regular Allen keys, but they are awesome. I have yet to see one strip after using them for several years, even extremely small ball-point sizes like 5/64".

In addition, because they have a better contact profile against the hex sockets in the screws, they reduce the chances that you will accidentally strip a screw. I have also seen screws that were "stripped" being easily removed/tightened with these high-torque Allen keys.

Re: Buggy BAG Motors
 

Thanks for the heads up on the High-Torque Allen wrenches. I'll add some to my next McMaster order and give them a try.

Re: Buggy BAG Motors
 

Chuck I've been using them all this year and they have been great. Buy the sizes you use commonly in bulk. They're worth it.

Re: Buggy BAG Motors
 

Paul, our shooter failed twice in eliminations at FLR -- not positive it was the BAG motors (which we had already checked for dead spots before installing them as replacements for the bad ones), but we're going to pull them once we get the robot out of the bag at Buckeye, and I'll send them your way. I'd love to hear what you find with those two in particular, as they tested good before use. (I'm not saying the failure was the motors. I can't figure out what else it could possibly be, as our shooter worked great all through quals and nothing changed, but at the very least it will be another data point for you guys as you work through this issue).

Thanks for your prompt attention to the matter. Your customer service is great! (As are your mecanum wheels and versaplanetary gearboxes!)

Re: Buggy BAG Motors
 

We ran into the same issues. I PM'd Paul about it, and he says the runout on the RS-550 shaft is horrible, which would explain things. What does your magic spacer look like? Can you post it here or on Thingiverse?

BAG motor problem
 

So i have a strange motor problem, the BAG motor is connected to a spike relay - i turn the spike relay on and sometimes the motor docent spin. I have to give the motor a push to get it going.

the batteries are fresh and the motor has no load. i checked all connections and nothing seems to be loose.

Re: BAG motor problem
 

See this thread:
http://www.chiefdelphi.com/forums/sh...hreadid=114411

Re: Buggy BAG Motors
 

We made a couple of different types of spacers to play around with, but all of them worked. The simplest one was simply a 3D printed "washer" that was a tight slip fit inside the motor plate and on the boss of the RS550. We also made a more complex part that additionally piloted the RS550/Motor Plate assembly to the gearbox itself, but this didn't seem any better/worse.

Dustin will post the drawings as a white paper.

Runout in the RS550 shafts sounds like it is the main culprit, and would explain the vibration issues we see when the shaft alone provides piloting.

Re: Buggy BAG Motors
 

Hopefully today. Heh. On account of there's this Lone Star Regional tomorrow and the 3D printer is at work and all...

I could draw it myself, but I don't have the parts available to check fits. Speaking of, what did you guys print this on? A commercial printer, or a Reprap derivative?

Re: Buggy BAG Motors
 

Had there been any verification yet if this is caused by use or if it happens fresh out of the box? I'm wondering how best to help teams who may encounter this at my regional this weekend.

Re: Buggy BAG Motors
 

In our experience it happens after several hours of use. Every one of our BAGs worked great on the bench, and in the first couple hours of testing.

Re: Buggy BAG Motors
 

Kevin, the files you are looking for are in the white paper here:

http://www.chiefdelphi.com/media/papers/2782

Re: Buggy BAG Motors
 

We've encountered both. We had several "test bad" right out of the box, so didn't use them. Unfortunately, we thought a "tested good" BAG would prove reliable, but at this point I would not be comfortable saying that is the case.

Re: Buggy BAG Motors
 

The only valid test is to run it for a good while several times. I have one that is used all the time and has never failed. While this is OK for teams with practice robots like ours, it will be difficult for teams that don't.