CIM Quiz 2

Does not compute.

For the FP @ 10.5 volts and 35 amps it says
0.222 Nm, 623.7 rad/sec… = 138 watts, not 180 watts.

The spreadsheet is pretty busy. Am I reading it wrong?


cim w/ 1:12 gearbox, fp w/ 1:6

How did you come up with these numbers?

my head, since the RPm of an Fp motor is roughly double that of a cim, the cim will have to travel twice as fast

CIM max power is 337 watts @ 2655 RPM
FP max power is 184 watts @ 7500 RPM

Total max power is 521 watts
sqrt(521*81500) = 6516.25

6516.25/2655 = 2.45
6516.25/7500 = 0.869 = 1/1.15

But why increase either motor’s speed by a factor of 6? What led to that decision?

(though it’s worth noting that it’s closer to 3.5 times…

15600/5310 = 2.94


Looks good.

The data I have here shows the FP max power 184W at 7800 rpm. The FP would draw slightly less current and run cooler if geared for 7800 instead of 7500.


I just noticed: how did you add 337+184 and get 674 ?


… Ill advisedly.

Wow. Not sure what happened there. I’ll have to check the excel sheet I made, tomorrow.

Edit to add:
Apparently I mis-clicked in excel, and selected the CIM motor’s output power twice. Oops!