Most powerful 550 size motor

[martin417]

Which FRC legal 550 size motor can deliver the most raw power? It used to be the Fisher Price, but that motor is no longer legal. Is the BB-550 really a 250 watt motor at 9,600 RPM as suggested by Ether's motor calc app?

[JamesCH95]

I would take pretty much anything Ether publishes to the bank. However, I would be suspect of how long a 550 could last at those power levels...

We have found the RS775-18 motors to be very robust, provided they are mounted in such a way that they are electrically isolated from the chassis.

[gpetilli]

JVN has done a great job tabulating the motors in his JVN-DesignCalc.20130105 spreadsheet. He shows the RS-550 as 245W however the 550 uses an internal fan and you must keep the input and output vents clear and it does not last long at stall (peak power, slowest fan). The CIM, Mini-CIM and Bag motors are sealed with no fan (last year some teams reported bearing issues with the Bag motor that is reportedly resolved).

The 775s are also air cooled, but have significantly more surface area and I believe they are more rugged. The 775-18 is 266W. Note that all motors over 120W must be on a dedicated speed controller - so the best option might be 2x RS-545-12 (2 x 73W), but you still have the fan problem.

[Alan Anderson]

The 2014 Motor Performance Data document might be a good reference for you.

Find it on the FIRST web site's Technical Resources page.

[Joe Ross]

Originally Posted by gpetilli

Note that all motors over 125W must be on a dedicated speed controller - so the best option might be 2x RS-540-12 (2 x 122W), but you still have the fan problem.

You might want to look at R51 again.

[gpetilli]

Originally Posted by Joe Ross

You might want to look at R51 again.

My bad - the 540 is in the same category as the CIM with 1 per controller. The 545 can be two per controller (2x 73W) which may still be a good tradeoff. The 775-12 (not -18) is also okay at 2x 82W but obviously physically bigger.