Allowable motors early info

Last year, many teams ran into issues obtaining gearboxes and motors for their designs due to the great amount of teams purchasing said motors from companies, most notably Banebots.

We received our gearboxes and motors the day after ship, which caused us to have to make a switch between two qualification rounds.

This should not have to happen how it unfolded, and there are ways FIRST could have easily made it more possible to have these gearboxes to work with.

First of all, they could have given Banebots more forewarning of the amount of teams that will be purchasing the gearboxes, and made them more prepared to handle the extra load.

They most of all should have forewarned teams which motors they can use on the robot this season and what quantity months in advance. This would allow experience teams to “stock up”, and rookie teams to receive their orders quickly during the season. I just don’t want to have another year where an issue like this caused a loss in testing time, preventing us from really getting much practice and tuning in.

These are just my thoughts, feel free to comment, and suggest a course of action. I believe we need to truly notify first of what happened here and that it needs to be fixed.

I have to assume that FIRST has talked to BaneBots about the intended use of all these motors, as part of their order. If FIRST hasn’t explained this, they need to.

Assuming that, my preferred course of action would be to put BaneBots on a kind of probation.

Explain the constraints, and tell them that the continued purchase of thousands of BaneBots motors is contingent on a few things:

  1. FIRST just handed you a pile of money for all those motors. Don’t take this for granted.
  2. There’s one string attached: you need to guarantee that there will be sufficient stock of that exact motor, all the way through the season. If you’re not willing to guarantee this, inform FIRST prior to making the sale.
  3. There will be a lot of orders in January, because FIRST has kindly created a monopoly for you. The least you can do is keep the customers happy.
  4. There’s only one way to make customers really happy: sell good stuff at a fair price, and deliver it fast. (You’re a third of the way there, at best.)
  5. FIRST’s participants demand real spec sheets, from the manufacturer. Provide them. Even if they’re in Chinese.
  6. Don’t advise your customers to induce a short circuit to sever a winding, in response to a manufacturing defect.
  7. Stand by your product. Unless you make it clear that you’re selling these motors as is with no warranty, it’s your duty to make sure the product is fit for use. (But if you’re not going to provide product support, don’t bother trying to sell motors to FIRST. They aren’t equipped to deal with unreliable suppliers. They’ll just find someone else to import the same goods.)
  8. Ask FIRST (in confidence) for a summary of the motor-related constraints that will apply to teams. Understand that teams are bound by these rules, and don’t suggest options that would cause them to violate those rules. This especially means no substitution of motors—only the exact model will do.

While that might be a lot to ask of an ordinary business, BaneBots isn’t an ordinary business. They exist in large part due to the competitive robotics market, and ought to be able to serve that market without making stupid mistakes.

As for the gearboxes, my advice to BaneBots is to spend a few thousand dollars on testing. Figure out the limitations of your products before you sell them.

While i am not happy about banebots taking a VERY long time to machine the parts, i’d say that next year we can at least take preventative measures to make shure that we arn’t in the hole this year.

Banebots is likely to give the same motors… The kit motors don’t change frequently, just look at the FP’s. So i think the banebots motors will stay. My team’s been around for a while, so we have 10+ banebots gearboxes of various ratios.

I think that the easiest way out of this is to stock up on a few common gearboxes. 64:1, 24:1 for the middle power motors (RS-550, 540, if i remember correctly) seem to be commonly used. I think that while we can complain all day, the most sucsessful solution would be to buy a few, and trade with other teams if nessisary.

personally, the only gearbox i would consider using with a bane bots is an double doozie, you can run it with one motor, and if you dont have enough power / things are binding / you want a more controllable movement, then add another.

You’ve conveniently provided me with a perfect opportunity to comment on a common misconception. The kit motors change almost every year. They may look the same, they may even be called the same thing (roughly speaking), but they’re not.

I can recall at least nine different Fisher-Price motors provided in the FRC KOP over the last 13 years. (A surprisingly long time…) Eight of those types looked almost identical (because they were RS-550 can motors). They range in power from around 140 W to around 400 W—so there are serious concerns about equivalence, and therefore FIRST rarely allows substitutions. That’s why I alluded to the manufacturer’s spec sheet above—it’s the simplest way to know exactly what you’re getting.

Similarly, BaneBots has made the mistake in the past of selling motors without changing the information on the website to reflect that they were no longer supplying the ones from the KOP. Normally, caveat emptor might apply—but this was a FIRST supplier, who surely should have known that FIRST teams were relying on the accuracy of their website to buy spares of the motors that they’d supplied. (If they didn’t know, FIRST screwed up in not making this clear to them; if they did know, they have no excuse.)

As I mentioned above, this is a bad idea. Legal motors change.

But more than that, by buying gearboxes, you’re investing in inventory. That cost is now sunk into what’s effectively a capital asset, which you can’t easily liquidate when you want to use it for some other productive purpose. That forces you to go to the great inconvenience of setting up a market for these gearboxes after the fact—a market in which delivery time might be improved, but sufficient supply is very uncertain. Bad as BaneBots order fulfillment history is with these gearboxes, I find it hard to believe that this will be much better, especially given the possibility of uneven demand for certain gearboxes.

As a summer project we are going to look for mass produced off the shelf alternative gear boxes. Mainly power tool and automotive units. Every one should be familiar with the Devault hack. We are looking to do the same with others. I found a seat positioning motor gear box that looks to be adaptable to a RS540 - RS550 motor. Well constructed unit and looks like a plate and pinion change is all that is needed. Also, the mini cordless drivers look promising. We used 5 banesbot gear boxes this year. While we did not break any , there were to many problems, shipping delays and substantial cost. Got to be something better out there. I found some surplus precision servo motor gear boxes online for 33$. List price is around 310$. Could we account for them at 33$ on the BOM?

Gdeaver if you do find gearboxes that work it would be great if you could post them for the rest of the community. I worked with Joe P when he was writing the Nothing But DeWalt paper and I know how much it helped the community. One thing you might also want to look into is gearboxes from power wheels type toys like the fisher-price gearbox. I believe that 1114 had great success in using different gears from those gearboxes to quickly make custom gearboxes for their robot this year. I did some hunting in the past and found a couple that use the 775 can motors I never bought any to test but this could be a interesting option and they were under $30.

It looks like I found something great!

This site has a comprehensive drill gearbox modification how to.

A lot of the Banebots issue is they way they build every transmission to order. I’m wondering if they could instead give teams the option of buying the stages and housing in kit form so we could assemble them ourselves. Usually Banebots shipped in a day or two anything they didn’t have to assemble.

You can do this now by ordering all the parts seperately but that’s pretty tedious.

This. When we ordered replacement/upgrade parts for our P60s, we always got them with a good leadtime. This in the midst of the 1 month P60 backlog.

I’m convinced that BB’s problem isn’t inventory or part supply, but assembly time. They’ve so far insisted on shipping their gearboxes “pre-assembled” with no grease. So you have to disassemble them anyways to grease them. Meanwhile, they have to have people spend something like 15 min or more per gearbox assembling it, leading to ridiculous leadtimes when they get hit with orders for thousands of gearboxes.

If they simply offered an unassembled kit form of the P60s, everyone would be happier. They’d save time and labor costs. We’d get gearboxes faster. And there wouldn’t be this pointless wasted time of assembling gearboxes that will just need to be disassembled again. They could even make things easier for themselves by packaging things in complete planetary stages. A bag for a 5:1 to 5:1 stage, a bag for a 5:1 to 4:1 stage, and a bag for a 4:1 to 4:1 stage, and bags for the 5:1 and 4:1 output stages. Shipping an order would be a simple as grabbing the appropriate stages and tossing them into a box with the correct ring gear, mounting block, and output shaft. And then you fire it off to another satisfied customer. The only real obstacle to this is writing some assembly instructions so people know what order the stages go in.

Sage advice. I hope some operations people from Banebots are listening.

I do recall at least a few teams buying P80 gearboxes as stacks of replacement parts that they later assembled on their own. (At least one such team posted a picture of their pile o’ parts here on CD.) While I can’t be sure of their motivations, I’d assume the absurd lead times that developed brought them to this solution.

If any team does decide they ‘need’ to stock gearboxes, I’d definitely do it in unassembled parts. That way, you can pick and choose to get the gear ratio you need. Also, when the motors change (and yes, as noted, they change quite frequently) you don’t end up with a pile of spoiled inventory. While it’s a pain to list out the BOM for each gearbox yourself, it’s just paperwork. You could purchase those parts now for either the P80 or P60 that Banebots offers. If a motor changes next year, you should just have to buy a new motor plate for the gearbox to get everything working nicely.

Even if the parts won’t be put in inventory, there’s still something to be said for buying unassembled gearboxes. You get exactly what you need (shaft length and all). You avoid a greasy mess (if you had naively purchased a greased P80, for example). And, you get a great teaching tool for how gearboxes work. My team is seriously considering this approach going forward.