Jeff - the rule of toe is - on a given motor the larger the prop, the slower it will spin and the higher will the current draw be...

For ANY motor you expect to find three pieces of info to guide you:

1. Voltage range - x cells to y cells (where x < y)

2. Prop range - AxB to CxD (where A < C)

3. Kv - rpm per minute per input volt

When behaving like a decent human being (i.e. not killing motors), you normally choose the LARGER prop with the SMALLER cell count.

Example:

http://www.hobbyking.com/hobbyking/store/__18121__turnigy_aerodrive_sk3_3548_1050kv_brushle ss_outrunner_motor.html

1050Kv, 3 to 4 cell battery, and (prop data not there, but I know it) 11x5.5 to 14x7 prop range.

You expect to normally see this motor on 3S with a 13x6.5 prop give or take for 3D and 12x8 for sport flight. You expect to see this motor on 4S with a 12x6 or 12x4 for 3D and 11x5.5 or 11x8 for sport.

---MAV

Marc A Volovic

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