Legally Increasing Motor Performance

[kiettyyyy]

Originally Posted by JesseK

I heard a rumor from a fellow mentor, who heard it from a well-respected team. It's actually pretty ingenious if it's true, and it's legal as far as I can tell. I'm somewhat skeptical though since I didn't hear the info first-hand and won't have the time to test it for a couple of weeks.

Does running a DC motor in water, specifically a TETRIX motor in de-ionized water, clean out its internal windings enough to noticeably increase its performance? If so, does anyone have relative performance gains?

We definitely ran our motors underwater.

Prior to the Los Angeles regional, we ran our motors on a variable power supply set to 15 volts, current limiting to 3 amps. The motor was run for roughly a hour and a half till its free spin current(comm was coupled to a .25" shaft supported by a Tetrix bushing) dropped under .25 amps.

A couple weeks before the championship event, we heard about the water break in method.. After googling for a bit, we came up with this link(http://www.wattflyer.com/forums/showthread.php?t=7409) in addition to a few youtube videos of RC competitors breaking in their motors underwater.

We went ahead and used a 3 to 1 ratio of deionized water and 99% isopropyl alcohol(helps get rid of the water inside of the motor after we're done with the break in). After submerging the motor underwater, we turned on our variable power supply and let it run at 15 volts for roughly 15 minutes. At the end of the 15 minutes, we dried the motor and put it back on the power supply to measure free spin current. We were able to drop the motor's free spin(without shaft) to 0.09 amps at 15 volts. Attaching the motor to a shaft and running it at 15 volts resulted in having a current draw of 0.18 amps.

We also attached reflective tape to our minibot shafts for testing of motor speeds via contactless tachometer. Without either break in, we were coming out to roughly 9200 RPM at 15V. After the break in, 9800 RPM at 15V.

There was a significant performance increase. I'll post a few videos of our minibots(before and after)...