There are many different computer programs out there that are useful for predicting how your power setup will perform.
One good one that I use a lot is www.motocalc.com
. Problem is, these programs are only as accurate as the specifications that are provided by the motor manufacturer.
Case in point is my new Hyperion ZS3025-10 motor. Running this motor through motocalc showed results very close to the Hyperion 3025-10 motors published performance data.
Problem is, in the real world, the 3025-10 performance is far off from actual results. With the 12X6 prop recommended by Hyperion, the current and watts pulled is off by some 40%.
So, what to do???
I just ran some tests on this motor, with a 13X6.5 Prop, powered by a 5S1P A123 battery pack. The results were plugged into motocalc. The Hyperion motor specs were tweaked to match the actual performance data. Next, further tests were conducted with an 8X5 prop, and no prop. Results are attached.
The original Hyperion KV spec was 775KV. Tweaking that KV number to 640KV resulted in the motocalc predictions being within about 5% on the prop sizes tested.
So, if you have a no-name motor, or a motor whose specs are quite a bit off, just tweak the KV rating spec of the motor, and this will provide some guide on how different sized props will work. If you've got a motor mfg that does not provide the motor winging resistance, that can really provide problems with these computer programs.