Motor Comparison Chart

[PowerfulKitty]

VexPro has made this handy chart to help compare most motors for FRC. Its nice having all the units the same hand having everything side by side.

For most of the motors the values all seem quite proportional: except for one. Can anyone explain why the free current for the new 775Pro is so low compared to all the other motors, even the weaker ones? Does it really matter, for all intents and purposes?

http://motors.vex.com/

[Kevin Sevcik]

Near as I can tell, it has dual ball bearings instead of sleeve bearings. So less resistance from the bearings.

[Joe Johnson]

Also, I can't remember the last time I cared about free current.

It matters most if you are doing some sort of inferred sensing (e.g. I don't have a speed sensor and I want to estimate speed or torque buy measuring current and voltage -- in this case the free current is needed to model the motor correctly).

Very nice data from Vexpro by the way. Thanks for pointing this out.

Hold Strong,
Dr. Joe J.

[Kevin Sevcik]

I think the most valuable data is the 3 minute max power and the stall torque curves. Pretty interesting that the "high power" 775s lose to mini-CIMs after just 10 seconds. They probably lose even faster if you're accidentally on the wrong side of peak power.

[FRC Warrior]

Why do 775 Pros drop max power so suddenly?

[PowerfulKitty]

The 775Pro's are intended for shooters and such, where they can run at high rpm. They are fan cooled, so if they stall they fry in 4 seconds.