Originally Posted by andy120
Working from Motocalc i have come up with 2 motor/gearbox sets for my 69" BT spitfire driving a near scale 16.2" prop.
Scorpion S2-5525-210KV at 1.25:1 and a Scorpion HK5020-450KV at 3:1.
Is there a prefered ratio region?
Having gone through a number of Astroflight brush type geared motors, and the pain in the
they represent, can you simply go to a direct drive motor?
I've got a $$$$ Hacker A50-16S motor that turns a 16X12 APC-E prop direct drive from a 6S2P A123 battery pack. That A123 battery pack would be close to a 5S 4000 Mah LiPo. Perhaps other less costly motors can also do the job? This A50-16S motor turns my 16X12 prop at about 6000 RPM while pulling about 55 Amps, and 1000 Watts.
Hacker has a number of different motor "winds" on the same size motor frame for use with different number of cells in your battery pack.