zonker123

My Feedback: (21)

OK not new to helies but new to the electric aspect of the sport. Got a TREX less motor for Xmas. There are so many choices for motor /pinion combos that my head is really starting to hurt. Local HS as the new EFITE hackers in stock, these are 400 size motors. One is rated at 3700 kv and the other is 4900 kv. My battery choice is TP 3S2100s gen II. I will do some moderate 3d but nothing beyond basic flips, loops, and rolls. Please tell how to determine the best way to fiqure the starting pinioin size in assciation with the KV rating of the motor. I know the head speed for aerobatics needs to be in the 2200-2400 RPM range. Just looking for decent performance with decent flight time with out burning something up.

I guess a need a primer in brushless motor application education.

thanks
zonk

VinceHerman

fxaeromodels.com has a pinion calculator that takes all the information that you gave and tells you what to expect for head speed.
I have a new TRex, with a mega 16/15/3 and plan on using a 3 cell LiPo. The Pinion calculator says that I can expect 2442 head rpm with an 11 tooth pinion.

I do not know how accurate that really is, but I am starting assembly today, so I will find out soon enough. (oh, ok, I have not ordered the berg receiver or the gy401 gyro yet, so it still will take a while)