Can CIM's compete anymore?

With the release of the falcon, can CIM’s even compete? They are considerably less powerfull than Neo’s already. The falcon makes Neo’s looks like a joke (on paper). So for poorer teams that cant afford either, or shifting gesrboxes how much of disadvantaged will be seen? Neo’s and shifters were king last year. How can teams that can’t afford either get there hands on some? I hope some falcons come in the KOP. But I doubt it.

Very little. The biggest real advantage to the new motors is weight for the power provided. A 3 CIM drivetrain is realistically going to perform very similarly to the new fancy motor drivetrains.

For our team, literally the only reason we used NEOs last year (and are considering Falcons this year) is because we’re always up against the weight margin and we don’t reuse old motors anyway. If we couldn’t afford them, we would deal with it and build with less weight.

At the end of the day, the drivetrain’s job is to make sure you don’t lose matches. This is the same reason it doesn’t make sense for most teams to do mecanum/H-drive/swerve – it adds extra complexity and expense, and you’re not super likely to win more matches just by adding features to your drivetrain.

If you don’t have that much money and are trying to maximize competition performance over everything else, spend the money where it counts (your mechanisms). Equally importantly, make sure you build within your means – for teams with relatively little money, that means minimize robot functions (and therefore, likely weight too). This will remove a lot of the advantages teams with more money will have over you.

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+1
I was literally just typing the same response

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@plusparth pretty much nailed it. That last few percent of power and efficiency might make a difference on Einstein, but things like strategy and driver practice are what get you to Einstein.

Only this year, where having a lot of pushing power mattered, and even that isn’t nearly as important as the wheels used and, as you said, drive skill

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This won’t change a thing for ~90% of teams in FRC.

That’s a generous estimate.

As always, as the market matures, so will the prices as initial production costs are absorbed.

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I’m going to guess that at most events next year, there’s going to only be 1-2 teams with Falcons. Maybe 15% of the teams will have brushless motors in any capacity unless they show up in the KOP with an associated controller.

For the next few years, CIMs will work. By the time they’re horribly outdated, I suspect they’ll be cheap enough and distributed enough through the KOP and FIRST Choice that it won’t be too big of a deal.

We swapped from 6 minicim to 4 neo drive between regionals and champs last year. The robot went a bit faster and had a bit more pushing power, but the big advantage was having more weight to improve our cargo intake, which led to another 1-2 cycles a match. If we weren’t at max weight, it wouldn’t have made much of a difference.

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1293 has more or less abandoned the CIM. For the last two seasons, we ran Mini CIMs (four in 2018 when we were idiots, six in 2019) and it is the default choice for our 2020 drivetrain motor because we prefer to implement mature products rather than chase the ragged edge of performance. As others (shoutout @Paul_Copioli) have gushed about in the past, we’ve found it makes a noticeable difference in performance and leaves more room inside the robot.

The main thing that would be the nail in the coffin of the CIM is a cheap upgrade to a 3-CIM gearbox for drivetrain. Yes, this is me campaigning for a 3CIM4U revival again.

The good news is that brushed motor controllers are generally cheap and abundant, and teams transitioning over to NEOs and Falcons will increase the size of the “yeah, we can give that to a team needing them” pile. Combine with a solid understanding of how to use 775 motors effectively, and you can build a robot that will see Saturday afternoons.

There are definitely advantages to the brushless motors, but the difference is still small enough that game design variance year to year can essentially erase that difference with more bounded fields.

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I have to say that we would have killed for Falcons on last year’s robot. We were hard up against the weight limit and had to use miniCIMs on the drivetrain (mecanum.) We still had a lot more pushing power than other teams assumed we would, since we were running 12:1 planetary gearboxes on each drive motor and that gave us more push than is usual with mecanum. But the ability to cut out the weight, add considerably more power (and higher RPM on the output), and have a built-in encoder (we already use Talon SRXs with mag encoders) would have simplified and lightened the whole drive/control system in ways that would have been very useful. As it was, we were shoving around WCD and tank drive robots, despite the supposed disadvantages of our drivetrain. With these beauties, we’d have been that much faster and harder to push and could have upped our cycle time by another hatch or two per match. We’d have also been able to cut the weight of our climbing mechanism by another 6 pounds. I’d call that well worth it.

I’m sure for a lot of teams, these motors won’t make a real difference. But I also know that for our team, we’ll be ordering several in the next few days.

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Nope, they are obsolete. Please send your old useless CIM motors to my PO box so I can properly dispose of them.

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We used cims in 2018 and 2019 and are now switching to the Falcons as we want to upgrade to the latest and greatest. Neos are still a very viable option for teams.

And for the majority of teams that only use 2 CIMs per side on their drivetrain? How will they compare?

There’s more than one way to be good. We ran 6 mini CIM single speed gearboxes in 2019 and it’d be hard to argue that NEOs would have made a positive difference in robot performance. Identify what resources you have and focus on maximizing return on investments.

Edit to add direct answer: Yes, CIM’s can compete just fine.

These graphs were generated using a Release Candidate of 2020 changes to my drivetrain simulator and are representative of a cycling game like 2019.

TL;DR: The KOP drive train is more suited to every game than anyone gives it credit for. Kudos to AndyMark for consistently nailing it!

4-CIM 2019 KOP drive train @12.4V (10.71:1 ratio with default “long” configuration) with no current limit (theoretical 13.0ft/s @ 12V):

4-NEO configuration geared for 13.0ft/s @ 12V (theoretical), with a 56A current limit and blue nitrile 4" wheels:

4-Falcon500 configuration geared for 13.1ft/s @ 12V (theoretical), with a 58A current limit* and blue nitrile 4" wheels:


*NOTE - CTRE’s current limiting algorithm is not quite the same as REV’s, so the throttle responses may differ slightly.

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For reference, according to the usage reporting from FIRST, 18.6% of teams had a SPARK MAX object in their code, which is probably a solid proxy for how many teams actually used NEOs on their robot last year.

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Even if you can’t afford a fully decked out Falcon robot, you can for sure use them smartly in 1 or 2 places and get 95% of the robot performance compared to someone who has a fully decked out BLDC robot.

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This year, sure. The Falcon hardware seems great. But, how does the software work? That always seems to be the lagging component of new motor controller hardware. And, will they be available? In the last few years, we’ve definitely seen issues with vendors not having enough stock of new components to supply demand. There’s a lot of risk there.

Our first use of Falcons will likely be in an off-season robot build. If they work there, then we’ll probably buy a supply to have on hand at the beginning of the following season.

You could have used neos…