CIM Motor Sacrifice

[billbo911]

Originally Posted by onecoolc

Have any teams used two RS-550s in a CIM-U-LATOR in place of a CIM? If so, what were your results?

I've seen a lot of posts in this thread with grievances towards the RS-775 (and case shorts), so I'm wondering about experiences with the RS-550s, if anyone can share.

After testing our prototype shooter, powered by a single CIM, we decided to make a change. The CIM was more than sufficient for our plans, but we believe they are better suited for our drive train.

Based on the results of our testing, we made the following adjustments:
The single 340Watt CIM, driving 8" wheels, reduced 1.8:1 with chain sprockets will be replaced by 2 250Watt RS550s attached to a 5:1 reduction CIM-Sim from AndyMark. The output will either be direct driving the shooting wheels or go through a 1:1.8 chain sprocket increase. Either way will work out, but the 1:1.8 increase should have the motors running at about 50% power.

We plan on using and encoder and PID loop to maintain the desired RPM. Running the motors at 50% power will allow us plenty of overhead to control RPM during shots and when the battery starts to fade near the end of a match.