CIM motors RIP?

Would you say that CIM motors are no longer relevant in FRC with better option like the NEOs or Falcons? I’m pretty sure there are a lot of team making the switch, the questions is what todo with your CIMs stock? Would selling them be a good idea taking into consideration that it might not be smart for an FRC team to invest in them… what are your thoughts

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CIMs are pretty tough. And they’re cheap. (And there’s power conservation arguments to be made as well.)

They’re definitely relevant still.

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I’d say atleast for now they still have a place, especially with people able to reuse old motor controllers, and anyone trying to save a little bit. But in the next few years, they will presumably be phased out basically.
The current brushless are lighter, don’t have as much degrade on performance (so I have been told), and will hopefully push to get more motors coming out.

All and all brushless finally hitting FRC is only a positive note as it helped lead to many new tools available, just compare to something like 2014 to now and many changes and advancements have been made, even by just pushing some of the current hardware. While cims do still have a place, it is going to get smaller and smaller, with lighter and more compact motors around.

CIMs are still really useful for a couple things. First and foremost is that they’re easier to test and prototype with than any brushless motor. You can plug the motor straight into a battery and it’ll spin. Adding a drill or potentiometer to this setup makes it even more useful as you can control the input voltage (speed). You can even through a fuse in line for added safety. Brushless motors, however, absolutely need a controller and a bit of software (unless you use a controlling device like the one @pfreivald linked further down this thread) to function. If you have a test bed set up with the controller and software ready for testing this point is invalid.

The other things CIMs have on brushless motors is that you can still them for pretty much the whole duration of a match and they’ll be fine once they cool off. I don’t know how Falcons deal with stalling (probably a lot of breaker trips?) but NEOs die after about 2 minutes. Of course, stalling motors to hold position on mechanisms isn’t the best design practice but it works and is the most accessible option for teams lacking in the software department.

If your team can afford to build up a stock of brushless motors, go for it. Don’t throw all your CIMs out though, because they’re definitely still useful. You can also always bring a few to competitions in case a team needs a replacement, and I would wager that the large majority of the motors used on FRC bots are CIMs.

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From a power conservation standpoint, using a brushless option is much better. They are more efficient by a wide margin, so you can run them at lower amperages and get the same mechanical power output.

We’ll see less and less CIMs used over the next decade, but unless the rules ban them I’d be very surprised if they go away entirely in that time.

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Pretty much this. Four of them is fine for the kit drivetrain, and a 6-motor gearbox adds a healthy-enough chunk to the BOM to rule that out.

Once brushless CIM-class motors become cheap enough to implement as the rookie kit default, I think we’ll really see them die off. Right now, one CIM with a Victor SPX is $82.98 retail, and the cheapest brushless alternative (NEO with SPARK MAX) retails for $115 retail. So there’s still a little room to go.

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There’s still like a team or two using Jaguar motor controllers even. CIMs will take a long time to disappear.

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For FRC purposes CIM’s are still relevant, but their power density and weight are making them less and less viable. I think the brushless revolution is here to stay and we will see less and less CIMs as time goes on, especially if weight limits for FRC robots start decreasing.

I designed a few tools/machines using CIMs knowing our stock of them would mostly go to waste otherwise this past off-season. With a simple AC/DC converter, a pot, and a switch, you can make a handful of really simple machines and tools. Still haven’t made any yet, but I think they could be really useful in some shops. If you have CNC capabilities making the parts for these are fairly trivial, but if not it is still quite simple to make.

Here is a quick example of a CIM belt sander:


Onshape:

It’s probably easier and definitely cheaper to just buy the harbor freight version, but this was a fun design exercise, and I have no doubt this one would last longer than the one from HF.

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Now you have me wanting to make one with a Falcon. All I need is a PDP, a Main Breaker, an RSL, a RoboRio, and I should be good to go.

There is something to be said for the simplicity of wiring up a CIM, and the lack of computer control needed to run it, especially for small projects and prototyping.

CIMs are still relevant. There are will probably be less CIMs and more brushless as time goes on, but CIMs still have a place in FRC. Heck my collegiate robotics team uses even older motors that still work. (mostly not FRC legal but…)

CIMs are easy, just need a motor controller and your pretty good to go. For brushless (NEO, for instance) needs a brushless motor controller that’s more expensive.

I would say keep those CIMs, I would bet they may still be handy for you.

Technically speaking all they need is a battery.

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You don’t need software. This little beasty (https://www.amazon.com/WHDTS-Generator-1-Channel-1Hz-150KHz-Adjustable/dp/B07NJ1SL3N/) plus an old PDP and some CAN (or pwm) wire is sufficient to get a decent level of control out of a Falcon 500. I believe the AndyMark “Thrifty Throttle 3” is the same idea.

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While I have a very loving relationship with my neo’s (they can dodge bullets), I don’t think that my teams are going to get rid of our Cim’s anytime soon. They are still great beater motors for testing, or for mechanisms that are going to experience a lot of abuse or don’t need that light of a motor. My teams are definitely starting to use some of the new brushless motors, and we probably will be using them more and more, but we still have a place for our good old Cim motors.

Dude, that is pretty sweet.

I wasn’t aware of these. Thanks for the correction. I’ll edit my post accordingly.

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Of all the brushed motors, CIMs (and more accurately miniCIMs) will be the last ones to die out of the FRC ecosystem. Their durability and consistency is still very good, and not everything needs absolute max power density.

Plus teams are slow to adopt and have to deal with budgetary constraints. My team this year is using all brushed motors for those reasons. We’ll probably be okay.

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I was just about to bring up budget.

Many smaller younger teams will take years to accumulate brushless motors.
We spent a lot of our budget years one and two getting a solid supply of motors and controllers, some are still brand new in the box. When we need a smaller motor to achieve a task we will shell out, but until then we have to stick to CIMs.

I think a decent amount of teams will be in the same place.

Anecdotal experience here, but we managed to smoke one after about 2 minutes of stalling.

Cant say the same, I have done somewhat of the same thing and it lasted for a very long time.