[Tristan Lall]

The specifications for the FR801-001 have changed over the years, but not by much. In 2003, the first year for that motor, the free speed was rated at 5 342 rev/min (±10%). In 2005, the free speed specification changed slightly to 5 310 rev/min (±10%). Power changed from 343 W to 337 W.

There's also the matter of whether the BI802-001A (CIM's number for the BaneBots M4-R0062-12) is actually equivalent to the FR801-001. I've never seen CIM's specification sheet for that motor to confirm this, but FIRST seems to feel that they are the same, and BaneBots publishes the same specifications as for the 2005-and-newer FR801-001.

And of course, the old AP801-001 (the Atwood Mobile MPD 71119 motor from 2002) has its own set of specifications. (Free speed either 5 500 rev/min or 5 600 rev/min, depending on which sheet you believe.) The old FR801-001 was based on this motor, without the inconvenient pinion shaft.

Was this the sort of variation that you encountered, or were you experiencing much larger discrepancies in performance?

*These changes were accompanied by a design change to the motor's keyway. Old CIMs had a keyway that continued off of the end of the shaft—probably cut with a Woodruff keyway cutter, while newer ones have a keyway with two rounded ends—probably milled with an end mill.