# Flywheel RPM

I didn’t see this thread anyway, so I’m going to start one. I am wondering what your team’s flywheel rpm is.

200 * 25 = 5000

How is 5000 rpm going for you? Can you turn all the flags easy?

@Joshua_L its overkill, and most of the time I tone down the power to 3500rpm

21:1 * 100 = 2100 RPM (with 5 inch wheels though)

https://vexforum.com/t/high-strength-chain-in-inventor/18913/1
This thread has 96:1 speed. I don’t even want to do the math on how fast that is. 200 rpm V5s. Is that… 19,200 rpm?
Dang! I did the math! (Maybe.)

Mine is 2 high speed motors with a 25:1 ratio to the flywheel (two 4" wheels). It works pretty well. I wouldn’t recommend anything past this as even my ratio is a bit overkill (I just like the sound lol).

Related flywheel question … Team A has two 600 RPM motors running their flywheel and a 5:1 gear ratio (60:12) on theirs that should net 3000 RPM (right?) and Team B has two 200 RPM motors running their flywheel with a 15:1 gear ration (60:12 and 36:12) that should also net 3000 RPM (right?).

Theoretically shouldn’t both of these have the same net result for torque and velocity (assuming no friction)?

Thoughts?

I may be off on this, but adding motors increases torque, not speed. Please correct me if I’m wrong.

Theoretically speaking, they should. However, internal gears tend to be more efficient than external gears, so if you can do a higher internal gear ratio, that’s better.

Yes, I think. Increasing motors increases power. Since the motors don’t turn any faster, this would give you more torque.

In this scenario both teams have two motors. Both motors start off essentially turning the same, they are just using different combinations of internal gear cartridges and external gears to get to 3000 RPMs. So, in my mind they would essentially be the same.

In theory you are correct. In theory, theory and practice are the same. In practice, well…

Personally, I think there is an advantage to having as much of the gear adjustment done inside the motor rather than outside the motor. There is less space, less weight, and potentially, less friction. There is also less to go wrong if we assume the quality of the parts inside the motors are as good or better than the parts outside the motors.

Agree with you both. Therefore (in my head), it seems that Team A has the better design. There are many other things that come into play (friction, compression of the ball, etc.) but strictly looking at the design, I’d think Team A’s design would be more efficient - but I’m not even close to a physics teacher, nor did I sleep at a Holiday Inn Express last night.

My team was running a 2500 RPM, and it didn’t work, but I think that we had a lot of friction on it. We are thinking about trying a 3500 RPM with turbo motors.

I’ve seen a 3000RPM max flywheel absolutely dominate. 2 V5s running 200RPMs on a 15:1 gear ratio. All the compression optimization and exit angle were well attended to and lots of driver practice. Shot from all over the field with an anecdotal accuracy of 80%.

Under the same conditions (load and spin time) which set of motors are cooler? If they are bout the same then few parts outside the motor is less work to maintain and less space.

2333.33 RPM on 4-inch wheels & 1 V5 motor.

We have 2 4" wheels at 3000 rpm with 1 V5 motor and it works very well

15:1 with turbo motors and two 4’’ wheels, so 3600 rpm. Its been pretty hot. Only part of my robot that isn’t usually broken.

How many V5 motors do you use?