Min speed on the CIMs?

[Gary Dillard]

Has anyone tested the CIMS to see what minimum speed they are capable of at no load (where the PWM frequency voltage is too low to turn the motor), or at any other known load where I can scale the performance curve?

[RyanN]

0RPM is the slowest I can get it to rotate.

Now then... I have been able to get them to spin very slowly, but I don't know the specific RPM. It all really depends on the motor and how broken in it is, or if it has any bad sleeves/bearings or whatever it has. When I was just learning C, I would bump up the PWM value from 127 until the motor would start to turn with the 884 and the IFI controller. I know the minimum throttle for the 884 is 3%, I'm unsure what it is with the Jaguar, but I doubt the CIM will turn with a 3% throttle anyway.

I probably haven't helped you a bit, but I figured I would give you as much information as I could.

[Ether]

Originally Posted by Gary Dillard

Has anyone tested the CIMS to see what minimum speed they are capable of at no load (where the PWM frequency voltage is too low to turn the motor), or at any other known load where I can scale the performance curve?

Assuming what you are asking for is open-loop motor performance curves (as opposed to closed-loop speed control capability of the motor controller), since you mentioned PWM (and not CAN)...

Note sure if this answers your question, but here is a link to CIM datasheet which has
the motor performance curves (speed/current/torque):

http://lib.store.yahoo.net/lib/yhst-...otor-curve.pdf

See attached GIF



~

[EricVanWyk]

This thread may be of interest: http://forums.usfirst.org/showthread.php?t=10182

[Manoel]

While testing the CAN-bus connected to the PC, we got a CIM motor with gearbox (~9:1) to spin with 6% output.

Not very useful data, but better than no data...

[Gary Dillard]

Thanks, that gets me in the ballpark. I know at some point the voltage pulse is just not long enough to drive the motor but I wasn't sure how low it would go; 6% is impressive, since the profile of the Jag's looks pretty linear (from Eric's post).