Banebots RS-775 Case Short

[Mk.32]

Simple, don't buy anything from them.

But seeing they are 4 of the motors we can use... and provide the simplest gearbox solution for those 4 motors....

[MrForbes]

No one said building robots was easy.

[Chris is me]

Simple, don't buy anything from them.

It's the American thing to do. We're not financially supporting BaneBots this year.

[the man]

What I dont get is that the banebots make up 4 of our motors and are notorious for the case short issue, but the Fisher Price only makes up 2 of our allotted motors. So why doesn't first just let us use 4 Fisher Price motors and get rid of the bane bots all together.

[AdamHeard]

It's the American thing to do. We're not financially supporting BaneBots this year.

Banebots doesn't manufacture any of their motors; I'm going to try to hunt down the chinese manufacturer/ source of their 550's and see if I can order directly from them instead of banebots.

[PayneTrain]

What I dont get is that the banebots make up 4 of our motors and are notorious for the case short issue, but the Fisher Price only makes up 2 of our allotted motors. So why doesn't first just let us use 4 Fisher Price motors and get rid of the bane bots all together.

The AndyMarks, BaneBots, and FPs are all in the same class.

[the man]

The AndyMarks, BaneBots, and FPs are all in the same class.

Point being we get rid of banebots and increase the quantity of another type of motor. Or find a different type of motor.

[EricH]

Point being we get rid of banebots and increase the quantity of another type of motor. Or find a different type of motor.
Halfway there! The AM motors are new this year. (And don't forget the ARA motor allowance.)

[Taylor]

Point being we get rid of banebots and increase the quantity of another type of motor. Or find a different type of motor.

BaneBots is giving $30 worth of free materials to all 2,354 registered teams to use as they see fit. That's a donation of over $70k. Not small change, and I'm sure BB does even more for FIRST that is not covered in this one donation. I don't know that FIRST is ready to thumb their collective nose at a gold sponsor with years of involvement in competition robotics (not just FRC) and many other worthwhile products. The 550-series motors, the gearboxes, the wheels - they're all quality products.

I agree, take the 775s for a long walk off a short pier. The customer service at BB leaves something to be desired (to be fair we're pretty spoiled by VEXPro and AndyMark). But to dump a strong supporting company of FIRST? That's just not good business.

[the man]

Selling faulty motors is not good business either. But I see your point. I know we will be using that $30 credit just because its free.

[OZ_341]

Our team has a no Banebots products policy.
We will not even use the voucher. If every team did this, a message would be sent about customer service and fair business practices.

[Dad1279]

What I dont get is that the banebots make up 4 of our motors and are notorious for the case short issue, but the Fisher Price only makes up 2 of our allotted motors. So why doesn't first just let us use 4 Fisher Price motors and get rid of the bane bots all together.

Putting the 775's aside (as we are this year) you can still use:
4-550s
4 AndyMark Motors
2 FP (from a selection of 4, many of which teams have spares from prior years)
4 Cims
4 Windows
+ vex & Densos
1 Compressor

No team should have trouble finding enough (reliable) power for their drivetrain & mechanisms from the above selection.

[Tristan Lall]

BaneBots is giving $30 worth of free materials to all 2,354 registered teams to use as they see fit. That's a donation of over $70k. Not small change, and I'm sure BB does even more for FIRST that is not covered in this one donation.To be completely fair, their cost for those motors is clearly less than the retail price. Also, they can be reasonably certain that many teams will not participate in the voucher program, and that they will recoup a portion of their costs because they're in a monopoly position (because they don't disclose their supplier, which effectively limits our ability to get these motors on the open market, potentially at a better price).

I'd have a hard time believing that they do not turn a profit as a result of the FRC season. Contrast that to many of the other KOP suppliers, like Fisher-Price, which are only grudgingly in the business of selling parts to the public at all.

[JesseK]

AndyMark is out of the FP-673's [am-0821]. Because it's also a FIRST Choice item, are they not going to be restocked? If not, the 550's might be the only other option for a >200W lightweight motor on the shooters. I'd love to join a Banebots boycott on principle but unless AM gets more FP's in, we won't really have a choice.

[sanddrag]

They gave me $30. I gave them almost $500 in return, and I'm not even comfortable with my quantity of spares at that dollar amount. If anyone else is buying like I am, I'd assume BaneBots is doing just fine.

Other than order processing slower than molasses in an Alaskan winter, I haven't had a problem with them yet. I'm giving them another shot, since there really is no other competitor in their niche market.

[Jon Stratis]

AndyMark is out of the FP-673's [am-0821]. Because it's also a FIRST Choice item, are they not going to be restocked? If not, the 550's might be the only other option for a >200W lightweight motor on the shooters. I'd love to join a Banebots boycott on principle but unless AM gets more FP's in, we won't really have a choice.

Straight from AM's website:
http://www.andymark.com/product-p/am-0821.htm
AVAILABILITY: (updated Jan. 20th, 2012) Good news and bad news: GOOD: We have an order for these motors, and we will get delivery from Mattel. BAD: We don't have shipment confirmation of this order, and we don't know when they will be arriving (and available here). Hopefully, we will know more early next week (Jan 23-24). We do have am-0912 in stock, and it has the same mounting and shaft geometry as this motor.

[banebots]

We are a bit confused by the constant stream of BaneBots bashing on this forum. We understand that some people have concerns with the RS-775 so let me give a bit from our perspective.

We sold the RS-775 18V motor for 3 years prior to introducing it to FIRST last year with no problems and believed it to be a robust and reliable product. As a result of experiences by FIRST teams last year, we have been testing every RS-775 prior to shipping. We have had conversations with only one customer concerning manufacturing defects with an RS-775 purchased this year and replacements were sent out the same day.

Given the number of RS-775 motors shipped since implementing the 100% testing practice and the very low reported number of problems we believed our testing adequate. It should be noted that no attempt is made to fix any motor that fails testing - failures are removed from product inventory and isolated where they can not be accidentally mixed in with tested product. It would appear from posts in this thread that we may need to review parts of this process. We would ask for a bit of help from teams that have made posts about recent failures with RS-775s. We are particularly interested in posts by the following teams:

Team 1114 (post 224)
Team 1323 (post 231)

as both reported 100% failure on motors recently received and we have had no contact from them. Can someone from each of these two teams please post or send us your order number for the order you received these in and a detailed description of how you conducted your tests. Your order number will let us track to a particular lot of motors and your testing procedure may help us to enhance ours. We thank you in advance for your prompt response to this request.

As for some of the other stuff in this thread and on this forum in general, I'm not sure what to think. At a minimum it makes me question our continued support of FIRST. I'd ask that folks step back and read some of what is being posted from an objective view point and consider what kind of impression it leaves not only on BaneBots but on this forum and FIRST.

[h1n1is4pigs]

we have been quite satisfied with banebots this year, all the 775s we ordered work perfectly as do the gearboxes, we were also very satisfied with the shipping time we ordered and within a week or so had the order in time. from our teams opinion banebots has been doing an infinitely better job as compared to last years problems.

[Andrew Lawrence]

We're for sure using our 550's for our bot, not matter what. While we personally haven't had any 775 problems, we decided to put off our orders for now. Along with that, we don't really need a 775 motor on our bot at the moment; The 550's work great for what we need!

[Karthik]

We are particularly interested in posts by the following teams:

Team 1114 (post 224)
Team 1323 (post 231)

as both reported 100% failure on motors recently received and we have had no contact from them. Can someone from each of these two teams please post or send us your order number for the order you received these in and a detailed description of how you conducted your tests. Your order number will let us track to a particular lot of motors and your testing procedure may help us to enhance ours. We thank you in advance for your prompt response to this request.

Order #7163022

All motors showed a small resistance (less than 2 ohms) between the terminals and the case. This is the same symptom we saw from our motors last year. Our order numbers from last year were: 7151274, 7150067 and 7145378.

[Tom Line]

Order #7163022

All motors showed a large resistance (over 4 M ohms) between the terminals and the case. This is the same symptom we saw from our motors last year. Our order numbers from last year were: 7151274, 7150067 and 7145378.



Chastising your customers in a public forum for complaining about defective products that you supplied? That's an interesting brand of customer service to say the least. In general the FIRST community are one of the most forgiving population samples that you'll ever find. The fact that there's been this much outcry about your products and customer service from a group that's normally very tolerant should absolutely leave an impression upon you.

Some people here actually defending other banebots products like the 550's and the P60 transmissions. Frankly, that's a testimate to how forgiving this community is. We saw 50% failure on our 775 motors last year. Some shafts were locked up coming out of the box. Some good ones later developed case shorts. Yet we still bought some products from banebots this year, though we'll never buy a 775 again (we even had one fail during championship inspection).

[Akash Rastogi]

As for some of the other stuff in this thread and on this forum in general, I'm not sure what to think. At a minimum it makes me question our continued support of FIRST. I'd ask that folks step back and read some of what is being posted from an objective view point and consider what kind of impression it leaves not only on BaneBots but on this forum and FIRST.

Chief Delphi is not the FIRST majority, take the generalizations here with a grain of salt.

As other have stated, we very gladly support purchasing of 500 series motors as well as P60 gearboxes and Banebots wheels - all of which I just put in an order for worth around $200.

[Andrew Schreiber]

We are a bit confused by the constant stream of BaneBots bashing on this forum.

I'm not one of the teams you asked about but I am from a team who had a very negative experience with your company last year.

Last year I was the lead mentor on a team. Now, we didn't have many design resources and our work was slow, we didn't figure out what sort of transmission we needed for our arm until around week 3. We placed an order for the ones for our arm as well as the ones for our roller claw. We waited, and when we found out that the parts likely wouldn't be arriving until after the end of build season we were forced to make drastic changes.

Now, I understand that supply issues happen. But I would have expected that Banebots, as a supplier to FIRST for many years, would have been able to predict demand better than they appeared to. When nearly half the motors in our kit are from your product line and you make the easiest to interface gearboxes it is pretty safe to assume that many teams will be ordering from you.

And ultimately none of this really matters because it isn't you who has to tell a student that we can't build their design because the parts took 2/3 of our build season to ship. That's why I have a sour taste in my mouth for Banebots. I think they make competitive products at a fair price. I plan on using them in some of my projects. But I cannot count on them to ship in a reasonable time frame because they lost my trust.

I hope this explains to you my negative experience, if it doesn't I would be more than willing to talk with you in private about it. I hope that next year at this time we are all praising BB because I really do think they make some good products.

[KrazyCarl92]

Having had major issues with the 775's last year, our team plans to use the 550's this year. They are a quality product, along with the gearboxes that banebots offers (provided you do not exceed the torque limitations on the gearboxes). We are slightly disappointed that we can't really expect to see our order any sooner than 2-3 weeks after it is placed, but we planned accordingly and have ordered in enough time so that we will get what we need.

As for the 775's I can't quite understand why they are still on the market. It seems as though there is something that causes these motors to short to the case consistently. So rather than throwing out the half that are shorted and shipping off the ones that are "okay" as per quality control, why aren't they looking to freeze the product line, improve the manufacturing process so there are no more shorts, and then roll out the product again when/if the short issue is fixed? These things don't just happen for no reason...there has to be a root cause of the shorting issue and it MUST be something that can be fixed. Do what engineers do and SOLVE THE PROBLEM. We thank you for your support banebots, but we resent your one faulty product that happens to be a valuable commodity in our competition.

[sanddrag]

As for some of the other stuff in this thread and on this forum in general, I'm not sure what to think. At a minimum it makes me question our continued support of FIRST. I'd ask that folks step back and read some of what is being posted from an objective view point and consider what kind of impression it leaves not only on BaneBots but on this forum and FIRST.I'll go ahead and stand up for them here. They offer a decent quality product at a fair price. Through family, I know what it's like to be a small company, and it isn't easy. Our 775 motor last year performed flawlessly and still does. Our 256:1 P60 on that motor wrecked its teeth, even with good grease, the steel ring gear, and the shaft very well supported, but we were exceeding the specified maximum torque with shock loads. We had zero problems with 64:1 and 16:1 P60s with 550s.

Banebots makes very useful products at really a very affordable price for what they are. There really is no competitor producing many of the products they do. The wheels are fantastic for certain applications.

Having come from FIRST way back in the stone ages when cordless drill motors/gearboxes and Skyway Wheels were the only game in town, I'm VERY glad BaneBots continues to support us.

Can the company improve a few flaws? Sure. Should we bash them so much on a forum to the extent they question their support for our whole program? No.

If you think you can do a better job than Banebots, you go try starting a company that produces and sells those same things and we'll see how that works out.

[R.C.]

Given the number of RS-775 motors shipped since implementing the 100% testing practice and the very low reported number of problems we believed our testing adequate. It should be noted that no attempt is made to fix any motor that fails testing - failures are removed from product inventory and isolated where they can not be accidentally mixed in with tested product. It would appear from posts in this thread that we may need to review parts of this process. We would ask for a bit of help from teams that have made posts about recent failures with RS-775s. We are particularly interested in posts by the following teams:

Team 1114 (post 224)
Team 1323 (post 231)

We have not contacted Banebots due to a few reasons:

A) We are darn happy with the p60 4:1 gearbox, literally we are using them all over the place.

B) We did not actually place the order, but if Adam (FRC973) has it please put it up. We put a bulk order in with 973 last year. Our issues happened after season even tho 973's happened during.

I am not remotely trying to be rude, but here's a perspective from our team:

In 2007 we used banebot gearboxes, we went through around 20-30 and even though we weren't remotely good that year. We still could not drive around. We found that a ton of teams were killing those gearboxes.

We bought the generation of gearboxes before the p60's and had issues with those. So we stopped using them in 08.

In 2009 we took another shot at them, we had the gears pretty much turn to dust as the gearbox on our intake exploded 4-5 times. Yes properly greased and well kept/mounted and the shaft was supported.

2010 we didn't bother using them.

2011, we took another shot at them and used the low reduction ones as basically an "integrator to fp's and other 550/775 style motors. We were extremely stoked and loved the new p60 line.

2012, we have ordered around 12 p60's and 12 rs 550 motors. Can't wait to get them. As they make our design a lot easier.

Banebots, the real issue, a lot of teams have here is simply that the 775 motor has lost teams a lot of matches and some of the products have been garbage.

We are still using parts from banebots but we've been bitten multiple times. There's only so many times a team will allow it, we as a team have the resources to just cut our own 32DP gears and call it day.

But we are still using banebots this year.

-RC

[Andrew Lawrence]

I'm constantly guilty of being a wall-rider for many scenarios, and this one is the same. Like I say a lot, both sides are at fault here.

CD community:
I understand that the 775 has not been working recently, and that we're all kinda frustrated about that. However, that doesn't mean that Banebots isn't a good provider. Our 2011 robot, while not too successful, was powered by 4 CIM motors for the drive and a BaneBots 775 for the arm, and not once to this day have we had a problem with it. I know other teams have had a multitude of problems with the 775, and while that is something to be spoken up about, it's not something to create a thread of complaints about. I, for one, wholeheartedly appreciate everything our friends at Banebots do for us. Companies like AndyMark, Banebots, etc. supply FIRST teams, and often work their hardest to ensure that we are getting the best of what they can offer. I'm no business owner, but I can tell you as a fact that companies like Banebots are no walk in the park to operate, especially with the high demands of build season. We are part of FIRST, and as stated before are very understanding people. And while that holds to be true, our reactions sure are not showing the gracious professionalism expected by us from not only our peers, but the world around us. If a problem like this shows up, we as FIRSTers have the duty to not only alert the manufacturer of the product with the problem, but to work with them to engineer a solution to it. We're here to change the world, not hold others back.

Banebots Company:
To start, I really appreciate all of the things you do for FIRST teams and the great products you have distributed for our use. I know the hardships it takes of running a business, and how you probably may feel by reading the comments on this thread. Like I said above, this is both side's problem. Banebots is a great company, and great companies need to know how to handle complaints, whether emailed directly to them, or posted on an online forum. I understand that what has been posted seems like people are "bashing" your RS 775 motor, however as a great company, you should know that this doesn't mean to get mad at the people, but to inquire as to how you can fix your product so the product is not only fixed, but better than it was before. FRC teams do the best in their power to make their robots feats of engineering unmatched by any other program available, and you should be honored to be part of the program. FIRST loves Banebots, and Banebots loves FIRST (Why else would you continue to sell us your products? ;)) You have always been an invaluable addition to every team's designs since you joined the FIRST family, and we all hope you stay with us to further explore the engineering experiences and opportunities to come.

Thank you to anyone who reads this, and I hope that both the CD community and the Banebots company will be able to engineer their way through this mess and confusion.

-Andrew

[team222badbrad]

We have had conversations with only one customer concerning manufacturing defects with an RS-775 purchased this year and replacements were sent out the same day.


We received those replacements today and I was told they checked out on arrival.

We plan on using 1 or 2 of the 775's for launching the ball to the hoop. :)

[KrazyCarl92]

If a problem like this shows up, we as FIRSTers have the duty to not only alert the manufacturer of the product with the problem, but to work with them to engineer a solution to it. We're here to change the world, not hold others back.

What if FIRST were to release the one rule that tells us which motors are legal and in what quantities well before kickoff (Game Hint)? It wouldn't give us any real advantage in knowing what to design for and all teams would be at an equal advantage. This would hopefully spread out the demand from a six week build season over a longer period of time and not stress our suppliers so much. We wouldn't run into as many problems with product shortages and lead times in the build season. This would be easier on teams and FIRST suppliers. Sure we could've purchased banebots motors and gearboxes before the season started, but we wouldn't KNOW that they would prove useful.

[AdamHeard]

With the openness of the current motor rules, they my as well update it for 2013 to any 500 size motor less than X amount of power.

[EricVanWyk]

If a problem like this shows up, we as FIRSTers have the duty to not only alert the manufacturer of the product with the problem, but to work with them to engineer a solution to it.

This. A thousand times this. I can't fix problems I don't know about.

[camtunkpa]

As Brad posted our motors arrived today and they tested out good.

We on 222 have been using Banebots for quite some time with little to no issues other then some poor design decisions leading to premature failure. We've used their 540s and 550s many times without a hint of trouble. Heck we even had no trouble with the 775s last season and that's what has lead us to decide on using them again. Banebots produces price friendly useful products. We are a low budget team and maybe that's why we aren't as quick to pass judgement. We don't expect to get a Ferrari When we are buying a Ford. Part of the engineering challenge for small teams like us is to take that Ford and use it for all it's worth.

Good luck to everyone and don't be afraid to call up Banebots if you have any issues. They were very responsive to our issues. Help them help us.

[Al Skierkiewicz]

All motors showed a large resistance (over 4 M ohms) between the terminals and the case. This is the same symptom we saw from our motors last year. Our order numbers from last year were: 7151274, 7150067 and 7145378.

Karthik,
Four Megohms between case and either terminal is perfectly acceptable. The failure in last year's motors were zero ohms in the same test. The amount you measured (if in fact in the megohm range) could be moisture in the air or your finger tips. I would expect that the fault condition would be in the zero to 1000 ohm range. The fault, as documented by others, in 2011 motors occurred when one or more windings became shorted to the armature. To fully test motors, it requires that the tester connect one probe to a terminal (it does not matter which) and the other probe to the case while turning the motor several revolutions. If the meter suddenly drops to near zero, then that winding is defective. A digital meter set to the continuity beep position will beep on a bad motor when the short is reached. No beep and the motor is likely good.
On occasion, shorts also occurred with excess solder migrating into areas of the motor that bypassed internal insulation. The measurement/test would give the same results. I believe that some motors would not show the defect until run for a while. I would suggest that teams run the motors prior to any testing.
In response to Banebots, I agree it is unfair at this point to chastise an entire product line for the fault of one product. They are trying to correct a problem encountered by their customers. Give them a chance. As others have found there are other motors in their line that teams are using with confidence.

[Karthik]

Karthik,
Four Megohms between case and either terminal is perfectly acceptable. The failure in last year's motors were zero ohms in the same test. The amount you measured (if in fact in the megohm range) could be moisture in the air or your finger tips. I would expect that the fault condition would be in the zero to 1000 ohm range. The fault, as documented by others, in 2011 motors occurred when one or more windings became shorted to the armature. To fully test motors, it requires that the tester connect one probe to a terminal (it does not matter which) and the other probe to the case while turning the motor several revolutions. If the meter suddenly drops to near zero, then that winding is defective. A digital meter set to the continuity beep position will beep on a bad motor when the short is reached. No beep and the motor is likely good.
On occasion, shorts also occurred with excess solder migrating into areas of the motor that bypassed internal insulation. The measurement/test would give the same results. I believe that some motors would not show the defect until run for a while. I would suggest that teams run the motors prior to any testing.
In response to Banebots, I agree it is unfair at this point to chastise an entire product line for the fault of one product. They are trying to correct a problem encountered by their customers. Give them a chance. As others have found there are other motors in their line that teams are using with confidence.

Al, this precise test was run, with the motor displaying failure characteristics. The 775's we received were definitely defective. Also, last year motors that initially tested as good, all failed after use in practice or competition.

[Brandon Holley]

Al, this precise test was run, with the motor displaying failure characteristics. The 775's we received were definitely defective. Also, last year motors that initially tested as good, all failed after use in practice or competition.

We had the same results. Even if we found a motor that checked out as "good", after some period of time running on the robot it would eventually short. Eventually every 775 we used became shorted. We went through about 6 or 7 of them I believe.


One other thing I want to add is in regards to what happened at the beginning of the issues with the 775 last year. While BaneBots is doing the right thing now and standing behind their product, this was not originally the case. If you go back in this thread to around posts #64 & 65, you will see testaments from teams here stating that BaneBots was not taking back their shorted 775 motors. Instead they were advising teams to do the "zap" method to fix them. While this method did usually give the motor a bit of a 2nd life, and they are now publicly stating they are taking them back and providing replacements, this was NOT the original tune sung when the problem first arose.

I am not trying to stir the pot or anything of the sort. Personally, I completely understand why some teams are choosing to not use BB components on their robots. We will be using components from BaneBots that are not 775s, and we certainly appreciate their support. However, our memory is not that short term, so we are cautious in our dealings with their components. We've had success with them in the past, and we've also had close to insurmountable failure.



-Brando

[Al Skierkiewicz]

Again,
I have to ask what resistance was measured in both cases, Karthik and Brando?

[OZ_341]

We had the same results. Even if we found a motor that checked out as "good", after some period of time running on the robot it would eventually short. Eventually every 775 we used became shorted. We went through about 6 or 7 of them I believe.

-Brando

Same here. Banebots cost us several matches in Florida last year. We re-engineered our entire drive train to eliminate Banebots for Philly and Champs and then did not have another electrical problem the remainder of the year.

My intent is not to bash Banebots or influence anyone. All I can say is that in a free market, I will not choose to use their products. We were not satisfied with the product, the delivery, or the 2011 response to an obvious defect.

The only way we will use another Banebots product is if we are forced to do so by the 2013 motor rules.

[Brandon Holley]

Again,
I have to ask what resistance was measured in both cases, Karthik and Brando?

I haven't tested any this year, so my recollection is based on last years, but it ranged from dead shorts to 1M ohm resistance on failed motors.

Typically if we got into the 10k 0hm range, we started to have massive issues. If we were above 1M ohm, we would typically run a match with that motor. If it was below that threshold, we would continue zapping to get it higher.

[Karthik]

Again,
I have to ask what resistance was measured in both cases, Karthik and Brando?

My apologies Al, just got a text from the person who did the test. Our failed motors were showing less than 2 ohms of resistance. The 4 M Ohms was what was seen last year after zapping the motors as per the suggestion of Banebots.

[Al Skierkiewicz]

Thanks

[Mr. Rogers]

The 775 was rock solid on our arm last year, we must have been lucky because we did test our motors a week ago off of our 2011 bot and they had case shorts, but we were not stopped in inspection and it didn't cause any electrical ghosts on our bot. If this one small problem was fixed, I would feel alot more confident because they really are good sized, powerful motors, and with the CIM-ulator, not a bad substitute for a CIM. But about half of the ten we ordered are case shorted, or the shafts are stiff. We still plan on using them though, we'll just have to try and isolate the mounting plates and bring a bunch of spares. And I'll know what to replace first if stuff starts to short or reboot.

[apalrd]

Anyone look at the 775 motor on the AndyMark gearmotor?

We checked ours today - About 1-2 ohms from either terminal to the case. It flickers to infinity if I tap the end of the shaft slightly. I didn't test it while running, and I can't really spin the shaft because of the gearbox.

Good thing we ordered extra 550's and P60's.

[sanddrag]

I can see it now: 2013 rules: Teams are allowed to custom wind one motor of their own design and manufacturing methods. :D

(Not bashing on BaneBots, just a funny thought that popped in my mind).

[slijin]

I apologize in advance if this post comes across as accusatory, but this issue does have to be raised.

As a result of experiences by FIRST teams last year, we have been testing every RS-775 prior to shipping. We have had conversations with only one customer concerning manufacturing defects with an RS-775 purchased this year and replacements were sent out the same day.

Given the number of RS-775 motors shipped since implementing the 100% testing practice and the very low reported number of problems we believed our testing adequate. It should be noted that no attempt is made to fix any motor that fails testing - failures are removed from product inventory and isolated where they can not be accidentally mixed in with tested product. It would appear from posts in this thread that we may need to review parts of this process.

With reference to posts 228 and 229, as seen here:
A RS-775 motor (http://banebots.com/pc/MOTOR-BRUSH/M5-RS775-12) is Ø1.85 in. A USPS small flat rate box (https://shop.usps.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10052&productId=10001641&langId=-1) is for items up to 1.625 in thick. That leaves -0.113 in for padding on each side of the motor.

And with reference to post 199: http://www.chiefdelphi.com/forums/attachment.php?attachmentid=11455&d=1326998264

However low the manufacturing defect rate is (and given Banebots' role as a dedicated FIRST supplier, there is no doubt that their testing is sufficiently thorough), many members have pointed out that the shipping process itself is accountable for a number of ensuing problems following product receipt. Therefore, it is likely that the fundamental problem at hand is not persay the manufacturing process, but rather the packing process which subsequently results in inevitable damage during the shipping process. If this is indeed the case, then any further attempts to improve control quality of the manufacturing process will likely prove futile.

The other problem that has been raised occasionally in this thread is the immense lead time on gearbox orders (we personally had to wait nearly a full 2 weeks for a shipment of P60s to arrive). As one of the few dedicated and valued FIRST suppliers, there is no doubt that a backlog would be inevitable, but this is the kind of problem that the company itself should acknowledge and address of its own volition.

That being said, the 775s (notwithstanding all defect receipts) have undoubtedly been an extraordinarily useful resource for those fortunate teams that have had success using them (as these teams have attested), to say nothing of the outstanding support for usage of the RS-550s (which, having had personal experience with, I can safely say were the only part of our robot that we never had problems with, for which I am eternally grateful). It is my hope that Banebots will remain a FIRST supplier and continue to support it and all the teams.

[Tristan Lall]

We are a bit confused by the constant stream of BaneBots bashing on this forum. We understand that some people have concerns with the RS-775 so let me give a bit from our perspective.

We sold the RS-775 18V motor for 3 years prior to introducing it to FIRST last year with no problems and believed it to be a robust and reliable product. As a result of experiences by FIRST teams last year, we have been testing every RS-775 prior to shipping. We have had conversations with only one customer concerning manufacturing defects with an RS-775 purchased this year and replacements were sent out the same day.

Given the number of RS-775 motors shipped since implementing the 100% testing practice and the very low reported number of problems we believed our testing adequate. It should be noted that no attempt is made to fix any motor that fails testing - failures are removed from product inventory and isolated where they can not be accidentally mixed in with tested product. It would appear from posts in this thread that we may need to review parts of this process.Thanks for dropping in to offer your comments. I think the core problem is that nobody has the full story—you hadn't been advised about the issues some teams were reporting, and teams weren't aware of your action to correct related product issues.

For example, I believe this is the first that we've heard about 100% inspection of the 18 V RS-775 motors. Perhaps teams would not have been so quick to decry the RS-775's apparent faults, if they'd known you were actively attempting to solve the problem. And while I grant it would have been a difficult decision to admit publicly on your product page that faults had been found, and that you were in the process of dealing with the issue, that acknowledgment would probably have changed the tone of this discussion. Without your input, the fair criticisms that have been raised weigh heavily against your products. Thanks to your explanation above, I'm sure that many of us are reassured that you're revisiting the RS-775 issues.

Now that you're in contact with us, the way forward is to bring us up to date, so that we can re-evaluate our impressions of your products and customer service. Would you care to summarize your testing procedures and results, to give us a better idea of the underlying issues? Also, could you confirm or deny the allegation that you were advising teams to burn out a winding on the motor as a partial fix for the electrical issue—and if so, could you characterize the decrease in performance, reliability and safety that might result?

FIRST teams are voracious consumers of information: we need information about motors and gearboxes that is timely and accurate. This need is driven by the compressed timeframe of the competition (just over 6 weeks of design and building), and by the fact that most teams have neither the stamina nor the impetus to seek this information in advance of the competition season. Additionally, since FIRST embargoes the rules until the kickoff date, any such efforts could easily be wasted, if FIRST elects to change the kit of parts or the robot specifications. The net effect is that around the first non-holiday Saturday of every year, two thousand teams will descend on your website looking for information. At this point, teams will be rushing to make design decisions, to place orders, and to build their robots. They definitely don't want to run the risk that what they buy is not fit for its intended purpose.

If FIRST hasn't informed you that this is the date by which everything needs to be in order, please take heed of that now. By participating as a FIRST supplier (especially one with an effective monopoly on certain parts), and whether you were explicitly informed of this or not, teams expect that someone—either you or FIRST—has determined that the motors you offer are of good quality. They're putting their faith in you, and linking their competitiveness to the products you provide.

Also, we don't mean to pin all of the blame on BaneBots, if in reality the fault lies with your supplier. In the absence of the manufacturer's datasheets and product reference, we have no way of knowing whether the motors they're providing to you consistently meet their OEM specifications. Supplying that datasheet to FIRST in advance of the FRC season, and posting it on your website would go a long way towards informing our opinions, and towards improving the FRC design process.

There's also another issue of which you may not be aware: FRC operates with strict technical specifications, particularly for motors.1 By substituting motors of similar specifications, without advising FIRST and without providing new specification sheets (for comparison), you create a dilemma for teams and competition officials: how can we rely on your spec sheets if you haven't acknowledged an obvious substitution?2

As for the issues with shipping packages with insufficient packaging, I trust you now understand the issues and will solve this problem expeditiously.

In terms of the gearboxes, I recall that in the past, when defective gearboxes were discovered, you reacted by sending replacement parts. I have no quarrel with that kind of commendable customer service. I can only hope (for our sake and yours, because I know that must not have been cheap to correct) that in the future you'll be a bit more rigourous with your gearbox testing regimen.

(We can revisit the other criticisms of various gearboxes—especially lead time—later.)

Finally, though I don't presume to know the details of your business, I can point to another FIRST supplier, AndyMark, as an example of a business that the FIRST community generally trusts. AndyMark was founded by longtime FIRST participants, so already they have an advantage—but their real strength is in their quick response to product questions and concerns, and their general willingness to offer satisfaction, even when they're not strictly at fault. (I hope I'm not putting them on too high a pedestal, but that has been my experience with them in the past.)

As for some of the other stuff in this thread and on this forum in general, I'm not sure what to think. At a minimum it makes me question our continued support of FIRST. I'd ask that folks step back and read some of what is being posted from an objective view point and consider what kind of impression it leaves not only on BaneBots but on this forum and FIRST.If people were writing baseless libel, then it would definitely reflect poorly upon this forum, and FIRST. But I don't think that's the case. While frustration is evident, the criticisms have not been exaggerated, nor have the comments been defamatory. Indeed, the exchange of experiences relating to a product or service is a fundamental feature of a free market system—people need to be able to meaningfully evaluate and compare goods in order to make economically rational choices.

If there's something you believe to be false, by all means, point it out and offer your corrections.

1 In contrast to other motors, which are permitted on the basis of part number only, FIRST specifies "the BaneBots motors provided in the KOP". This potentially precludes your substitutions (without a rule change). I'm not FIRST, so I don't know if this was intentional—but I suspect that it was to avoid confusion with other similar can motors you've offered previously or subsequently.
2 This happened in 2009. (More details are available if you desire them.)

[Al Skierkiewicz]

Everyone,
I think it is important to state the effect of shorted motors on FRC robots. In the event of a shorted winding to the armature, there is likely to be no significant degradation of performance in our applications. Only quality control style testing would indicate a drop off in speed or power and then only when measured using the type of instruments used in this testing. Where problems will arise on an FRC robot is when wiring errors occur on the robot such that an additional electrical path is established through both the shorted motor and the other fault. If this second path is established through the Crio chassis which is electrically tied to the negative terminal of the battery, the Crio +24 volt power supply will be compromised and that will result in Crio reboot. If the second path should be through a second motor, a variety of faults could occur. While none have been documented, these could be anything from tripped breakers to power supply fluctuations to electrical component failures. We all know that a simple test for frame continuity may not show a defect until the motor is rotated to where the short is actually connected to a brush within the motor. A single shorted motor on a properly constructed FRC robot should not (in and of itself) cause any additional failures. In the event of a short as witnessed in 2011, the frame of the robot would be alternately switched to the negative lead of the battery or the positive lead of the battery dependent on the motor direction command of the controller. As inspectors we are very concerned about frame shorts of any kind for two significant reasons. One occurs when two faulty robots become engaged and there exists two paths through frame and other electrical wiring that may cause significant damage to electrical components or sparks. The second is our desire to insure every team plays every match and is able to be competitive at every event they attend.
When you are building your robot please keep in mind that the Crio must be electrically isolated from the frame and that all electrical wiring be insulated. When an inspector points to something during the inspection process, he/she is trying to help you. He/she wants you to perform at your best. Good Luck.

[Jim Wilks]

We have had conversations with only one customer concerning manufacturing defects with an RS-775

If you never respond to our emails, how can you expect to get feedback from customers???

[Ether]

If you never respond to our emails, how can you expect to get feedback from customers???

Apparently they do not want to receive emails. See attachments.

[Taylor]

Apparently they do not want to receive emails. See attachments.



Yes, but on the "Contact Us (http://banebots.com/mm5/merchant.mvc?Screen=SPTS&Store_Code=BB)" page of their website, it has fields to send them an email inquiry.

[Ether]

Yes, but on the "Contact Us (http://banebots.com/mm5/merchant.mvc?Screen=SPTS&Store_Code=BB)" page of their website, it has fields to send them an email inquiry.

Yes I know. My point was a bit too subtle I guess.

[Taylor]

My point was a bit too subtle I guess.



No, you're fine. I was a bit dense.

I was caught off guard by your dry sense of humor.

[team222badbrad]

It's just about time for some testing. Perhaps as soon as tonight. :D

Fresh out of one of my FDM machines! ;)

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/429639_10151198041485416_198330940415_22338200_164 639328_n.jpg

[Tristan Lall]

It's just about time for some testing. Perhaps as soon as tonight. :D

Fresh out of one of my FDM machines! ;)That looks like fun. What's the polymer you used?

[team222badbrad]

That looks like fun. What's the polymer you used?

ABS (Specifically P430) If you want more information about it check out stratasys.com or dimensionprinting.com

[LH Machinist]

It's just about time for some testing. Perhaps as soon as tonight. :D

Fresh out of one of my FDM machines! ;)

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/429639_10151198041485416_198330940415_22338200_164 639328_n.jpg

Looks good! Are the spur gears a press fit?

[team222badbrad]

Looks good! Are the spur gears a press fit? No slip fit with a set screw.

[sanddrag]

Gearbox looks fantastic. Now I want to get our 3D printer running. I could just as easily lasercut some plates and throw a couple standoffs in there though.

[waialua359]

Gearbox looks fantastic. Now I want to get our 3D printer running.

Same here. :) Ours should be ordered and coming in within the next 2 months. Too bad it'll be too late for this 2012 build season.

[Nick Lawrence]

We will not be using RS-775 motors this year.

It's a risk we just can't take. However, we are using 550 motors for sure this year.

-Nick

[Mk.32]

We will not be using RS-775 motors this year.

It's a risk we just can't take. However, we are using 550 motors for sure this year.

-Nick

Same with us.
Just need some of those p60s gearboxes...

[Richard Wallace]

I can see it now: 2013 rules: Teams are allowed to custom wind one motor of their own design and manufacturing methods. :D This would be sweet.

[waialua359]

Banebots called us today and asked for info on our testing, results, and motor info (printed on motors).
We found several so far that have the case shorts, yet when in use on our shooter with the CIM-U-Lator, have seen no ill effects as of yet.

Since they are willing to solve the issue and send us new ones, we plan on using them.

[Joe Johnson]

This is a very sad day. I had high hopes for those 775s. I heard that all that was in needful in this case was to electrically isolate the motor can.

I have access to a 3D printer and some mad CAD and engineering skills, so... ...I thought I was all set.

But, two things disappoint me.

First, that what appears to be a good motor is really a ticking time bomb in many cases.

Second, Banebots. I know that they are a small company. But they just don't seem to understand what it means to a team when a their hearts are broken by something outside of their control, all the more so when the problem was known by the source of the problem.

BB has had a year to try to get to the bottom of this issue. Sorting motors is better than nothing but it hardly seems like enough given the severity of the problem.

Banebots has been a great supported of FIRST. I love a lot of their products and I love their prices (if you don't count the cost of poor quality biting you in the back when you can least afford it).

But, I am disappointed.

Joe J.

[Tristan Lall]

I can see it now: 2013 rules: Teams are allowed to custom wind one motor of their own design and manufacturing methods. :DThis is how arms races begin.

But then I got to thinking. Brushes? We don't need no stinkin' brushes! (If only we had a speed controller that would work.)

This would be sweet.It would be sweet seeing what you come up with, when mass-producability is thrown out the window. (Maybe not quite so sweet trying to beat you at your own game, though....)

[Joe Johnson]

I've slept on this problem. To use the BB775s or not to use them?

I really want to use them because they should be a great motor. I think that isolating the case (from anything, including other BB775s) will limit the damage to that one motor. If I am using 2 in parallel (e.g. in a large arm application), unless both fail in the same match, I can limp through the match with only degraded performance as a result.

But... ...I don't like to go this way unless I have some way of detecting the onset of the problem and changing it at the first sign of a problem.

Has anyone tried monitoring the voltage on the case live while the robot is in action?

I am thinking that I could have put connect the case to a resistor network. For example, I could put two relatively high resistors in series between the battery and ground and tie the case to the middle of these and monitor this voltage. This monitor voltage (i.e. the case) would sit at roughly 6-8V (1/2 battery) unless a short starts and then it would start going rail to rail 12V - gnd - 12V - gnd - ...

And this is when I would replace that motor.

What do people think of this scheme?

Joe J.

[Al Skierkiewicz]

Joe,
Anything less than 10K is likely going to get the Crio upset at some point. Don't forget that the voltage polarity on the case will reverse when the motor direction reverses. It will also have the speed controller switching component and any brush noise that might be induced as well. You monitoring needs to compensate for high noise and 15kHz for the Jag and 150Hz for the Victors.

[Joe Johnson]

<snip>
Don't forget that the voltage polarity on the case will reverse when the motor direction reverses.
<snip>

While this is true for the relative polarity between the two motor leads, it is not so for the can. The can will be shorted to one or other of the brushes*. The voltage on the can will then be pulled hard to Vbatt when that bit of the winding touches whatever side the Jaguar is holding to Vbatt and it will be pulled hard to Gnd when the motor turns such that that same portion of the commutator is touching the side the Jaguar is holding to Gnd.

As to noise and Jag PWMing, I think this the least of our concerns. A simple filter should make that bit go away.

As to the cRio getting upset with lower than 10K, I don't see how this comes into the picture.

Some ascii art:
Vbatt
...|
100 Ohm
...|
Motor Case -- RC filter (band pass) -- cRio Analog Input
...|
100 Ohm
...|
Gnd


The band pass should remove the DC offset of 1/2 Vbatt, allow the rail to rail swings (say 1200-18000 RPM motor speed so allow 20-300Hz or so), and remove the Jaguar PWM and other junk (1000Hz and above).

I am not a EE but it seems that there may be some room for a solution in that space.

Joe J.


*well, it will be shorted to both because the motor windings connect the two, but odds are the short will happen with the wire length to one brush being much shorter than the other so it will act like a short to that one brush.

[45Auto]

Has anyone tried monitoring the voltage on the case live while the robot is in action?

I am thinking that I could have put connect the case to a resistor network. For example, I could put two relatively high resistors in series between the battery and ground and tie the case to the middle of these and monitor this voltage. This monitor voltage (i.e. the case) would sit at roughly 6-8V (1/2 battery) unless a short starts and then it would start going rail to rail 12V - gnd - 12V - gnd - ...

And this is when I would replace that motor.

What do people think of this scheme?

Why worry about it when the robot is in action? You can't stop the game and do anything about it anyway.

Monitor the resistance between matches, change them out if it reaches a value bothers you.

[JamesCH95]

Why worry about it when the robot is in action? You can't stop the game and do anything about it anyway.

Monitor the resistance between matches, change them out if it reaches a value bothers you.

If power to the failing motor is cut then it may save a cRIO reboot and thus the robot will remain mobile for the match instead of being dead in the water for 30-60s.

[artdutra04]

If power to the failing motor is cut then it may save a cRIO reboot and thus the robot will remain mobile for the match instead of being dead in the water for 30-60s.If the 775 is completely electrically isolated (via both the case and output shaft) through plastic mounting plates and either acetal gears or timing belts, will the cRIO ever actually reboot if a motor starts to go bad?

[JamesCH95]

If the 775 is completely electrically isolated (via both the case and output shaft) through plastic mounting plates and either acetal gears or timing belts, will the cRIO ever actually reboot if a motor starts to go bad?

I recall somewhere way back in this thread that at least one team had an issue, in rare instances, with a pair of 775s shorting together , instead of through the frame. The current draw would tank the robot's voltage and cause a reset. This may not be an issue depending on your exact setup.

Joe said "I think that isolating the case (from anything, including other BB775s) will limit the damage to that one motor." which might be an issue if multiple motors are failing/failed and short together.

I guess I skipped a few details in my thought process :p

[Al Skierkiewicz]

Joe,
The Crio chassis is tied to the negative lead of the battery. The power lead to the Crio is not sufficiently low impedance to prevent (nor is the boost regulator capable of overcoming) a disturbance in the power to the Crio. If anything on the Crio finds a frame fault including the Crio chassis, considerable current (not full motor current of course) will then flow on that negative wire. It appears that in the motors opened last year, the majority of shorts occurred between motor windings and the armature. How close to one end of the winding that fault occurred is anyone's guess. A few appeared to be stray solder that migrated between a brush assy and the case. Another reason for concern is the possibility of two robots with electrical faults becoming engaged with current flowing between frames.
While it appears that the Crio can operate at less than 19 volts, the spec is to operate above 19 volts input.

[Tom Bottiglieri]

We are not using the Banebots 775 motors.

[jason701802]

The Crio chassis is tied to the negative lead of the battery.

I thought the chassis of the cRio was tied to 24V.


Another reason for concern is the possibility of two robots with electrical faults becoming engaged with current flowing between frames.


Even if on one robot the chassis is connected to 12v and on the other it is connected to gnd, nothing would happen if these two robots touched each other. Sure, you'd be able to read 24v between the (-) terminal of the first robot and the (+) of the second if you stopped the match and walked out there with a voltmeter, but there is no complete circuit for current to flow through. Both the (+) and (-) of the same battery would have to be connected the different parts of the chassis and/or frame for any current to flow.

[sanddrag]

We are not using the Banebots 775 motors.If you don't mind me asking, who is "we"? If 254 isn't using them, that really says something, because I know they do their homework when it comes to motors.

[Tom Bottiglieri]

If you don't mind me asking, who is "we"? If 254 isn't using them, that really says something, because I know they do their homework when it comes to motors.
254. I'm pretty good about updating my current team info.

[EricVanWyk]

Don't forget that the voltage polarity on the case will reverse when the motor direction reverses.

This is actually one of most common myths in FRC, perpetuated in a blue box in the rules each year. The real reason we isolate our frame is to allow the system to survive single-fault wiring failures.


Has anyone tried monitoring the voltage on the case live while the robot is in action?

I am thinking that I could have put connect the case to a resistor network. For example, I could put two relatively high resistors in series between the battery and ground and tie the case to the middle of these and monitor this voltage. This monitor voltage (i.e. the case) would sit at roughly 6-8V (1/2 battery) unless a short starts and then it would start going rail to rail 12V - gnd - 12V - gnd - ...

And this is when I would replace that motor.

What do people think of this scheme?

Joe J.

This is similar to the way the PD's prototype big brother detected chassis faults, except we pushed an active signal instead of using a resistor divider. The control system would be fine with 100 Ohms, but that'll burn three fourths of a watt. I'd bump up your impedances into the 5-20k range. You're signal quality will be unaffected but it can be smaller and safer.


If the 775 is completely electrically isolated (via both the case and output shaft) through plastic mounting plates and either acetal gears or timing belts, will the cRIO ever actually reboot if a motor starts to go bad?

No. A fully isolated but faulty 775 will not have an adverse impact on any portion of the control system electronics. I do not have any information as to whether or not this fault will have an adverse impact on the motor itself.


I thought the chassis of the cRio was tied to 24V.

To the negative lead through a fuse and a self-resetting fuse. If bonus current is sent through this path, the two race to see who will blow first. The single-use fuse rarely wins, but can go with repeated abuse.


Even if on one robot the chassis is connected to 12v and on the other it is connected to gnd, nothing would happen if these two robots touched each other. Sure, you'd be able to read 24v between the (-) terminal of the first robot and the (+) of the second if you stopped the match and walked out there with a voltmeter, but there is no complete circuit for current to flow through. Both the (+) and (-) of the same battery would have to be connected the different parts of the chassis and/or frame for any current to flow.

True. This is another myth that used to be in a blue box.

[Al Skierkiewicz]

Erik,
I have to disagree. While the fuse internal to the Crio is meant to protect parts of the internal Crio electronics, electrical faults on the robot can cause real voltage drops across the #18 wiring used to feed power to the Crio. This is well documented over the past two years irrespective of motor issues. With these faults current merely flows through the chassis of the Crio to the negative lead and out the power connector.
Isolated (electrically) frames have been part of the rules to prevent robot to robot electrical faults from causing sparks and fire on the playing field. The potential in this scenario is the ability to provide up to 24 volts at high current, through parts of the frame and any wiring that might be in the circuit. Anyone who has been around more than a few years remembers the spectacular displays, smoke, hot (incandescent) wiring and yes even some flame that occurred prior to the inclusion of this rule.
Jason, the common myth is that robot to robot contact usually includes not only the robot frame but appendages or robot parts when tipped over, which have reached inside another robot. This is the second or third path that most people forget. In some cases, current will continue to flow even after the robot is disabled and the main breaker has been opened. It is why inspectors are so critical when checking the insulation on all electrical connections.

[Ether]

Erik,
I have to disagree.

Al, Eric's post was rather long, and it's unclear which part of it you are disagreeing with. Would you please quote the portion you are disagreeing with?

[Al Skierkiewicz]

I could only disagree with Eric's response to my quote and answer Jason's question.

[sanddrag]

Ordered either late on the 16th or on the 17th. Received my order yesterday. Shipped on the 6th business day, arrived 2 days later. Beautifully packed, good fit and finish on all parts, no shorted motors (out of 3 775s). Looking forward to trying it out. :)

[AcesJames]

Received my order yesterday. Shipped on the 6th business day, arrived 2 days later. Beautifully packed, good fit and finish on all parts, no shorted motors (out of 3 775s). Looking forward to trying it out. :)

I'll add to this -

I ordered 3 775s and some 4:1 planetary gearboxes from BB on 1/10. Received the whole order, well packaged, on 1/13. All the motors passed our EE's load testing, and now they're being used in test beds with the programming team.

For me, BB has stepped it up quite a bit this year. No bad surprises so far.

[Ether]

I could only disagree with Eric's response to my quote and answer Jason's question.

So you are saying

1) The voltage polarity on the case will reverse when the motor direction reverses?

and

2) Electrically isolating the robot frame does not allow the system to survive an armature-to-case short in a motor?

If I've misunderstood, could you please clarify.

[Kohala2460]

I have been following this thread all season, ( of course after placing an order of what we could afford (2 775 BB and 775 BB gearboxes). If and maybe when we receive them, and they do have case shorts, living in a place where 2nd day air means 2 weeks (Really not exaggerating, unfortunately), shipping back for a refund and maybe working BB is not an option.

What I have gathered is that:

Run a 12 Volt across the each of the leads to the case and hope for the best?

Mount motors and such to lexan/Derlin if all else fails.

Anything else?

[Al Skierkiewicz]

No,
I disagree with a statement of myth. At the time that faults were first noted on FRC robots, the IFI control system was being used. It does not have a conductive case. However, robots with any electrical faults to the frame could under certain conditions cause current to flow between robots.

The polarity of the voltage present on the case of a failed motor can change depending on where in the motor the failure occurs. If the fault occurs with internal wiring/brush assy and the case of the motor is tied to the negative lead of the battery (or near that potential) when operated in one direction. Then a motor reversal in this case is likely to put the case at near the positive lead of the battery. If the motor winding alone is the source of the fault, then the polarity on the case will change with rotation and will vary with duty cycle supplied to the motor. There are other variables as well depending on the nature of the fault, such as in a motor where the commutator is bridged by solder splash or two windings are shorted together.

For those just reading the thread and those actively participating, please remember that motor failure is a common occurrence in motors other than the Banebots 775. Mishandling, improper mechanical design and stray metallic debris all contribute to these failures every year. While a failed motor in and of itself may not keep you from competing, other wiring errors will add to the fault and affect your ability to play. Consider for instance, a failed motor on a robot with an insulated Crio but a camera that has not been mounted with the same care. The camera and wiring, and the PD power supply will be affected.

[Ether]

While the fuse internal to the Crio is meant to protect parts of the internal Crio electronics, electrical faults on the robot can cause real voltage drops across the #18 wiring used to feed power to the Crio.

I'm trying to clearly understand what your intended meaning is.

"cause real voltage drops across the #18 wiring" strongly implies that you mean due to additional current through those wires caused by the fault condition. Was that your intended meaning?

[Al Skierkiewicz]

Yes

[Ether]

Yes

I don't see how a motor case short can cause an increase in current in the cRIO negative power lead if the cRIO chassis is electrically isolated from the robot frame.

Perhaps someone could post a sketch showing the current path.

[EricVanWyk]

I don't see how a motor case short can cause an increase in current in the cRIO negative power lead if the cRIO chassis is electrically isolated from the robot frame.


This isn't the appropriate thread for this, and I'd appreciate if this side bar could be split off.

In a double fault scenario, additional current can flow from the motor, through the chassis, into the cRIO frame, through the cRIO's fuse, out the connector, through the return wire, into the PD, through the PD's self-resetting fuse, to the negative return of the battery.

The question is a matter of timing: Which protection cuts out first? The four in play here are the cRIO fuse, the cRIO power supply undervoltage lock out (UVLO), the PD's self resetting fuse (PTC), and the return wire experiencing a rapid gaseous state transition.

My claim is that the PTC is doing what I designed that circuitry to do, and that it is cutting out first. It heals when the fault clears, and then the cRIO begins to reboot, as my fellow NI engineers designed it to.

[Al Skierkiewicz]

You need to think of the Crio power supply wiring as a resistor. While the entire motor current will not flow in the negative lead of the Crio (if it is tied to robot frame), what current does flow will affect the power input at the Crio. It only has to drop enough voltage to cause the Crio to reboot. When that occurs, all Crio output is disabled and there is no current flow through the motor.

[EricVanWyk]

We both agree that that wiring link is resistive and that the voltage it develops does eat in to the 24V supply's margin. We disagree on how much voltage is developed, how much margin the supply has, and how quickly the PTC blows.

The current necessary to cut out the entire margin budget is orders of magnitude beyond the points the protection devices cut in.

The PD schematic and design package are available for review on usfirst.org . If anyone is interested, please run the math.

[Al Skierkiewicz]

Eric,
All we are really worried about is the voltage change at the power input to the Crio. There does not need to be a trip in the PD. It is like adding huge amounts of ripple in linear power supply. All that has to happen is for the power at the Crio to upset the internal power sense and the Crio reboots. Considering that switching PWM is a significant component in the current in this line, the internal regulators of the Crio likely give up pretty easy. I suppose it is also possible that the 24 regulator gets fooled into restarting but I really doubt it. Added to the switching, you have sometimes huge amounts of RF generated by the brushes and switching, particularly in the Jag.

[EricVanWyk]

Al, I'm trying really hard not to be rude, but the math simply does not hold up. It looks like we'll have to agree to disagree unless you can provide evidence to support your theory that the UVLO fires before the PTC. I still believe it is behaving as it is designed to and how the math indicates it must.

Don't get me wrong, I understand what you are driving at. It is a perfectly valid theory, it just doesn't hold up in this situation. For this system, the current/time profile to trigger the PTC is much much smaller than the current/time profile to trigger a UVLO: On the order of 100-750x smaller, depending on the shape of the pulse.

[Andrew Lawrence]

Just got our 550's and 775's. Not sure if I should be scared or not...

[Al Skierkiewicz]

It looks like we'll have to agree to disagree unless you can provide evidence to support your theory that the UVLO fires before the PTC.
To what are you referring to as UVLO?

[EricVanWyk]

To what are you referring to as UVLO?

Under Voltage Lock Out. This is the generic term for a processor or device shutting itself down when it doesn't have sufficient voltage to guarantee correct behavior.

[Al Skierkiewicz]

Eric,
The PD is very well designed and works very well. Without any valid data I cannot tell you which trips first since the effect is the same, that is Crio reboot. With the relatively low impedance of the motor wiring back to the PD compared to the higher impedance of the Crio power wiring, it would appear that the majority of the fault current would flow back through the motor wirin when we first observed this fault, we were prototyping with a small motor that we had removed from a battery operated vacuum. The motor case was intentionally wired to one of the wires. I don't think the motor drew more that 10 amps.

[camtunkpa]

An update from 222. Our shooter using 2 775s has been working flawlessly. We have been periodically checking the 775s to make sure they check out ok. We've put about 60-70 shots through it between last week and this weekend. So far so good.

[Andrew Lawrence]

An update from 222. Our shooter using 2 775s has been working flawlessly. We have been periodically checking the 775s to make sure they check out ok. We've put about 60-70 shots through it between last week and this weekend. So far so good.

Same here! 256 has had no problems with our 775's.

[Jim Wilks]

On a more positive note, I received 6 RS-775-18's today from Banebots. All test out fine!

[Aren Siekmeier]

2175 has had 775s chugging through some shooter tests that we "borrowed" from last year's robot, and they've had no problems so far. Haven't done any case short tests since we first got them last year. However, because there are so many other motors available, we're going with 550s on the competition shooter just to avoid the headache other teams have experienced, and keep the 775s around for other testing. The 550s are just 20W less powerful than the 775s, and we think we can get by.

[Ether]

The 550s are just 20W less powerful than the 775s, and we think we can get by.

Although I doubt you'll be running them at max power for any length of time (at least I hope not), let's do some numbers anyway just for grins:

at max power of 251 watts, the 550-12 generates 267 watts of waste heat.

at the same power output of 251 watts, the 775-18 generates only 141 watts of waste heat.

the mass of the 550-12 is 218 grams. the mass of the 775-18 is 337 grams.

the ratio of waste heat to mass is therefore

550-12: 267/218 = 1.22

775-18: 141/337 = 0.42

[Aren Siekmeier]

Although I doubt you'll be running them at max power for any length of time (at least I hope not), let's do some numbers anyway just for grins:

at max power of 251 watts, the 550-12 generates 267 watts of waste heat.

at the same power output of 251 watts, the 775-18 generates only 141 watts of waste heat.

the mass of the 550-12 is 218 grams. the mass of the 775-18 is 337 grams.

the ratio of waste heat to mass is therefore

550-12: 267/218 = 1.22

775-18: 141/337 = 0.42




Yep, these are going somewhere where they're seeing mostly intermittent duty (not at max power when free wheeling, probably powering shooter down when collecting balls), so we aren't concerned about the heat. But it's interesting to see that comparison.

[jason701802]

Has anyone received any 775s recently who can comment on the condition in which the motors arrived?

[mehrkam]

We received 12 RS-775-V18 motors.

Test ran unloaded for 20 min
Checked for Case Short - none

Then we started using one on the shooter.. After some testing, case shorting was detected. That motor is begining to degrade and run at a higher temperature. We plan to use it till it drops. We want to develop a replacement and reliability plan for the motors in this application.

We implemented modifcations to improve cooling of the motor based on of the other threads. These included a spacer between motor and the CIMulator to permit air flow into the motor and cooling fins on the motor case.

[SoloRacr]

Has anyone received any 775s recently who can comment on the condition in which the motors arrived?

Team 907 has just received two RS-775-18's
One has a case short.

so, 50% failure rate
:mad:

Andrew Paul
907 Mentor
EYCI

[de_]

re motors coming from factory shorted

Wow. Even after last years feedback, the manufacturer has still not solved the problem. Worst still they apparently are not even doing simple QA tests on them before shipping. We (or Banebots) need a new motor supplier. I have 6 of these on order and I can't see how I can risk using them.

[slijin]

re motors coming from factory shorted

Wow. Even after last years feedback, the manufacturer has still not solved the problem. Worst still they apparently are not even doing simple QA tests on them before shipping. We (or Banebots) need a new motor supplier. I have 6 of these on order and I can't see how I can risk using them.

As Banebots has pointed out, they do run tests on their motors before shipping them out and advise any teams who receive bad motors to contact them asap. It's my opinion that motor defects upon receipt are the result of poor packaging (the shipment of 775s we received yesterday had pieces of broken Styrofoam, which I assume was there hold the 775s stable during transit).

We received a shipment of 4 775s yesterday, none of which had case shorts and were fully functional.

[EricVanWyk]

re motors coming from factory shorted

Wow. Even after last years feedback, the manufacturer has still not solved the problem. Worst still they apparently are not even doing simple QA tests on them before shipping. We (or Banebots) need a new motor supplier. I have 6 of these on order and I can't see how I can risk using them.

This problem has been notoriously intermittent, and I don't know of a good way to know whether a particular motor doesn't have the issue. Detecting a case short is a certain way to know that there is a problem, but not detecting the short doesn't mean that there isn't a problem. Rotating or jostling the motor can hide or expose the defect.

I'm of the opinion that the "case-zap" method doesn't fix or clear anything, it just shakes things up hard enough to push the defect back into hiding for a bit. It can then pass bench testing until something else causes it to express again.

I'm willing to believe that Banebots is performing best faith QA, and that the defect is too finicky to be caught by their testing. My suggestion is to teams is to treat all of these motors as defective regardless of testing and isolate them appropriately or switch to a different motor.

[RRLedford]

Has anyone received any 775s recently who can comment on the condition in which the motors arrived?

Team 3135 placed initial order for a pair of CIM-U-lator=>775 gearboxes recently (on Feb 1st)), along with a total of four 775 motors. Because of the internal shorting problem, we wanted to have spares.
Expecting at worst maybe one in four to test bad, our order arrived today with THREE SHORTED MOTORS (zero ohms) out of four. We are bailing out on using the 775 motors for ANYTHING EVER AGAIN. I hope we can get a replacement pair of DUAL 550 CIM-U-lator gearboxes shipped ASAP. Banebots may be testing these 775 motors, but if so, USPS is killing them in transit. Packing was adequate but not very good considering the known issues. The motors should have been rolled up with multi layer bubble pack surrounding them, and they were not.

FOLLOW-UP - GOOD NEWS
Banebots agreed to send us by overnight ship two back plates that would let us convert the CIM-U-llator gearboxes over from RS775 to RS550 (single or dual). Right now it's only for lack of the big gears and output shafts that is slowing down CIM-U-lator deliveries, but the aluminum plates are in stock. So, this lets us use dual 550 motors instead of 775s.
So, they sold us the two back plates for the price of one complete CIM-U-lator, and 3 extra mounting kits were also included.
BTW, for those waiting for 550 CIM-U-lators to ship, they would not move us to the head of the queue to swap a single 550 CIM-ulator gearbox for our one unusable 775 gearbox simply because of the three shorted 775 motors, even though we offered to overnight return the one of the 775 CIM-U-lator to get a 550 replacement. They understood that we no longer trusted using 775 motors, even free replacements, so, instead they proposed getting us the 550 backplates .
With this compromise, we are happy and feel taken care of by Banbots.

-Dick Ledford

[cfair]

I am glad to finally hear a few positive comments about Banebots in this thread. The RS775 has been a problem for everyone using it in the FIRST applications, but that's the way things work when you use a part in something other than its intended application (it's probably intended for harbor freight battery-operated drills, where you shouldn't be surprised if you lose part of a winding and a short to the motor case has no other negative effect). Banebots has been responsive whenever we have contacted them, and I like their planetary gearboxes. The 64:1, 16:1 and 4:1 gearboxes differ only in their ring gear length, so you can buy some 64:1 gearboxes and some shorter ring gears before build season starts, and be ready for most situations with very little money spent. I haven't found similar functionality for similar prices elsewhere.

[EricH]

For a robotics application, non-FRC, my team got several 775-18 motors (the 775-12 is being discontinued). Tests are pending for shorts; they will be used in a critical system. Yes, we made sure to get spares. (And the packaging? Motors in styrofoam, and packing peanuts filled the rest of the box except maybe where the P60 gearboxes were--USPS Priority Mail box.)

[Ether]

Banebots should be doing a dielectric test with a HiPot tester, not merely a resistance check with an ohmmeter.

[Tom Line]

I believe in giving credit where credit is due - especially when I pointed out banebots flaws so often before.

It seems they're learning. Returns are easy and aren't argued at all. The banebots we've gotten (8) have not had any case shorts.

I'll be retesting the ones we've been running on our shooter tonight- they've run for probably 20-24 hours of actual spinning time and if they haven't developed shorts now, they probably never will.

So, right now I'm giving banebots a golf clap for having improved their return mechanism, and seemingly doing a pretty fair job of quality checking their product.

In point of fact, I've had as many problems with AM products as I have with banebots this year. Of course, AM has so much good will built up with me they could probably just forget to ship something and I'd give them a pass!

[Ether]

I believe in giving credit where credit is due

So do I, but I think you missed my point.

Banebots claimed (http://www.chiefdelphi.com/forums/showpost.php?p=1112398&postcount=267) they are doing 100% testing of the 775-18's.

Since teams continued to receive case-shorted motors after that policy was implemented, it's a strong indicator that they are not doing HiPot testing, which would be the appropriate testing for this type of problem.

[avanboekel]

Just to confirm, the RS-550 doesn't have the same problem?

[EricH]

Just to confirm, the RS-550 doesn't have the same problem?
It's never been detected, to my knowledge. Just the RS-775 (I think just the RS-775-18, to be more specific).

[Gary Bonner]

Just to confirm, the RS-550 doesn't have the same problem?

We had a 550 with a case short. Don't know if it came that way or if the short developed from over heating. Our shooter is driven by two 550s in a CIM-U-LATOR that's been modified to allow air flow to the vents on the motor face. I've been told that the motors got pretty hot during one extended practice session, but continued to work fine. Then at our first competition, we failed the continuity test during inspection. We traced it to one of the 550s.

[Akash Rastogi]

Has anyone else had an issue with the PG-71 gearmotor's 775 shorting?

[slijin]

Has anyone else had an issue with the PG-71 gearmotor's 775 shorting?
We've had no such issue, but the only PG-71 we have is the one we received from the KoP; we found Banebots/FPs to suffice for all our motor needs.

Of the 10-odd 550s and 775s we ordered this year, none had case shorts. Whether case shorts will develop is something only time can tell.

[Andrew Lawrence]

Of the 10-odd 550s and 775s we ordered this year, none had case shorts. Whether case shorts will develop is something only time can tell.

We have the same deal. All Banebots motors, 550s and 775s, work beautifully, and have been throughout the whole build season.

The only problem we've had with our order was when someone accidentally smashed the shaft of our CIM-U-LATOR gearbox somehow (I think it was a freshman).

[EricH]

For a robotics application, non-FRC, my team got several 775-18 motors (the 775-12 is being discontinued). Tests are pending for shorts; they will be used in a critical system.
The testers report that they're all good motors, and they've been run-tested. I'll report back if we end up with any issues.

[Ether]

The testers report that they're all good motors

How did the testers test them? Just with an ohmmeter?