Andymark rhino drivetrain discussion

My team saw and bought two modules almost immediately after kickoff. I have seen many people mention how they are not totally necessary to over come the defenses. Post your thoughts here!

they are delayed by about 2-3 weeks, in case anyone is wondering…

We discussed numerous possibilities for wheels/traction/etc. last night - including the Rhino… There are less expensive ways to do the same thing, though we do think this is a great product…

Anyone know how fast these threads are rated for / how fast you’ve got them to go? Anyone cross 15 ft/s?

Our team has gone against them, but also discussed creating our own with the 2-3 week delay. I don’t think it would be that hard for a team to CNC frames and assemble the parts.

Just FYI belts/ pulleys typically have a 2-3 week turnaround time from most if not all suppliers. 1251 my team has done tank treads in both 2010 and 2012 so we’ve done quite a bit of prior searching.

Our second-year team purchased these as soon as they were available on Saturday and were just told they will ship by Thursday. We are a young team with limited machine shop capabilities. Rhino drive looks like it can handle any of the defenses easily depending on robot height and mechanisms.

If we were building a high goal shooter, we might want something more stable (no pivot point) and more maneuverable. For weakening defenses, should be great.

Frustrated at the whole “out of stock by the end of the first weekend” trope rearing its head again with FRC suppliers.

Look, I know it’s difficult. It’s a small market and it’s hard to predict demand, etc. But this can’t be the best that can be done. It’s hard/impossible to teach good engineering practice when you’re forced to rush to make your drive choice in the first day lest you not be able to purchase the parts you need until halfway through build season.

I understand that 2 or 3 cim motors are needed for each side of the Rhino drive.
Is each cim motor connected to its own motor controller?
How would one program this in Java?


8 inch pneumatic work fine

Yes, each CIM motor is connected to its own motor controller. The programming of multiple motor controllers is no different than controlling one motor per action in Java. You just have to make sure that every time you set the speed for one motor, you also set the speed for the other motor, in order to ensure that they are always going at the same speed.

These COTS treads ought to make for an interesting shift in what drive bases can do. I can’t wait to see how people respond to the “threat” of them appearing.

we cnc ed our own out and made our own belt. it is fast and i will try to get a fps. looking at the AM bumper kit and going to try to replicate something like it.

Could I use PWM splitters to run the motor controllers of 2 or 3 CIM motors at the same time?

Yes, I think you can, though my team has never done it before. In that case, I think you only have to control one motor controller.

R53 Each power regulating device may control electrical loads per Table 4-4. Unless otherwise noted, each power regulating device shall control one and only one electrical load.

one controller per motor is how i read it

Correct. It is 1 motor per motor controller. You can use a PWM Y-Cable (like provided in the KOP) to provide control signal to 2 motor controllers at a time.

Could I make a PWM Y-cable to control three CIM motors or really three motor controlers for the Rhino drive? Is there a better way to wire and program Rhino drive?

The simple answer to this is yes (although it is recommended you use the same type motor controller for all 3 motors, 1 motor controller per motor).

Alternatively you could use 3 different PWM ports on your roborio, and make them function the same in code.

I thought using one motor controller for three CIM motors was not allowed.