BaneBots

[Hawiian Cadder]

one way to prevent motors burning is to put in some software protection, if you have CAN on that motor you can limit the amount of sustained current eg, if more than 60 amps is going to the lift FP for more than .25 secs with no increase in speed, then kill it. we did this on two motors i believe, our roller and our lift, while the FP was a little harder to prevent from smoking, we stalled our roller every time we picked up a tube, and never had an issue with it.

[Chris is me]

Originally Posted by Hawiian Cadder

one way to prevent motors burning is to put in some software protection, if you have CAN on that motor you can limit the amount of sustained current eg, if more than 60 amps is going to the lift FP for more than .25 secs with no increase in speed, then kill it. we did this on two motors i believe, our roller and our lift, while the FP was a little harder to prevent from smoking, we stalled our roller every time we picked up a tube, and never had an issue with it.

The Banebot failures have nothing to do with stalls, at all.

[Ether]

Originally Posted by Chris is me

The Banebot failures have nothing to do with stalls, at all.

I don't think he was referring to the case-short defective motors or overtorquing transmissions.

His suggestion seemed to be directed toward preventing damage to a non-faulty motor.

[PAR_WIG1350]

We ran two 775 on our robot without issue. Luckily, out of 5 or so motors that we got, only one had a short, and the two that we did use never developed shorts. But, even if they had shorted out, it is unlikely that they would have caused much trouble at all since they were isolated from the frame by fisher-price transmissions.
Fisher price transmissions, conveniently, already have mounting holes for a 700 sized motor. Also, since the gears and casing are plastic, and not metal, the motors are isolated. It was plenty powerful too. At one point we bent a 5/8" anodized aluminum jackshaft and split a steel sprocket into three pieces when our robot got hung up on the scoring grid (fixed in between matches by replacing the damaged parts and by adding a polycarbonate plate under the arm so it would slide off the pegs).

[AdamHeard]

People seem to really get caught up in xyz motor being so fantastic, and yxz being crud.

People need to think of motors purely as power sources, with some varying factors. The torque and speed output obviously determine the power, and are useful characteristics to know.

The other useful characteristics, are it's thermal mass/ability to dissipate heat, it's friction/resistance which cause it to generate heat, and then obviously any sort of special notes about the motor (current limiting breakers built in, a built in gear reduction that adds friction, etc...).

I know this is a rough approximation, and there are some "lies" here, but it's a decent way for begginners to understand.

Assuming the 775 had no manufacturing defect, the FP, 550, and 775 were actually all pretty $@#$@#$@#$@# similar in terms of power production. The 775 could be considered the "better" motor there as it is much heavier, and is much more capable of dissipating heat. One could argue the smaller motors are better, as they weigh less for the same power. It really comes down to what you need them for.

People also seem to assume the small motors aren't durable, which may or mot not be true depending on how you define durability. They certain can't handle high levels of repeated stalls, but you shouldn't design them to! They are very powerful motors, and can do a lot of work without ever getting hot if your system is properly designed. As Chris on 330 says, run them fast! which means high gear reduction, so the motor is spinning closer to free speed.

We picked hte 775s in all four places this year, and had some issues with case shorts. We had zero issues in terms of burning or damaging them. Assuming it stays the same, the 550's thru a cimulator will probably be our preffered motor.

I also forgot to mention that banebots does not make these motors. They are a standard sized motor (395/540/550, etc...) that many different manufacturers will make, for many different purposes. Within each size, there are commanalities in the shafts, mounting holes, etc... It's not rocket science to interface to any one of these gearboxes, considering the absurd amount of options on the market for them.

[pfreivald]

Well, I know that we're experimenting with the NBD whitepaper after the BB gearbox fiasco of this year... I don't think I can ever count on them again as a supplier, and am indeed dubious of whether or not they qualify as a VENDOR under FIRST's rules.

It's easier to gain trust than regain it, and they certainly have a ways to go.

[Andrew Schreiber]

Originally Posted by pfreivald

Well, I know that we're experimenting with the NBD whitepaper after the BB gearbox fiasco of this year... I don't think I can ever count on them again as a supplier, and am indeed dubious of whether or not they qualify as a VENDOR under FIRST's rules.

It's easier to gain trust than regain it, and they certainly have a ways to go.

Depends on your definition of "within a reasonable time"... (My definition is before I forget what I ordered the part for)

[Teched3]

Not totally off topic, but FIRST think about providing teams advance notice of what motors are being used in the kit in advance of kickoff. This would be especially helpful If a new motor is being introduced (aka tetrix) that teams are unfamiliar with, and give some time for testing them to determine torque curves, mounting configurations, etc. Motors could be ordered and would spread out some of the vendor backlogs in delivery, and not reveal anything about the game.

[Aren Siekmeier]

We ordered and used 2 RS 775s without issue, luckily, after testing them negative for the notorious case shorts. They ran very nicely on our strafe wheel, not even getting warm. We actually had more issues with our FP, but that was because we sort of abused the leads when soldering to them.

We (and 3130) did, however, have bad experiences with Banebots' shipping delays. If we hadn't had the ability to run two CIMs on the strafe wheel before the shipment came, we wouldn't have driven really at all until week 6. And the options for powering our elevator were severely limited by the fact that we had to wait 3 weeks (or more!) to get anything. We ended going with a P60 from last year's robot and an FP.

[thefro526]

816 used Two RS775's and Two RS550's this year.

From what I've seen, the 775 is one of the most robust motors we've ever used (excluding case shorts) and will pretty much take anything you can throw at them including relatively long stalling.

550's are nothing new really, they're a fantastic and powerful motor in a compact package. We haven't used them in a high load application though, usually we use them for intakes and things of that nature - but I wouldn't hesitate to use them elsewhere if the designed called for them.

My real issue with Banebots is that their customer service and ability to handle high volume gearbox orders seems to be a bit lacking...

Originally Posted by Teched3

Not totally off topic, but FIRST think about providing teams advance notice of what motors are being used in the kit in advance of kickoff. This would be especially helpful If a new motor is being introduced (aka tetrix) that teams are unfamiliar with, and give some time for testing them to determine torque curves, mounting configurations, etc. Motors could be ordered and would spread out some of the vendor backlogs in delivery, and not reveal anything about the game.

^ I think this is an extremely good idea. If FRC were to release a list of legal motors in say, November, this would give teams plenty of time to familiarize themselves with anything new in the kit. I can't think of any way that anyone could find anything out about the game by telling us what motors we're allowed to use 2 months in advance.