Thread: New Product Hobby King EPP FPV plane
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Old Jun 17, 2012, 05:35 PM
wingsnapa is offline
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Australia, VIC, Metung
Joined Oct 2008
670 Posts
Prop choice

I might be on the wrong track here but I after using many 10 and 9 inch props I settled on one that only peaks at 30A.

This is because i divided the thrust into amps to compare props.

For example if my motor drew 30A @ 1000g of thrust, that would be 3A per 100g thrust rating.

The next tested would would give me 58A @ 1700g which is 3.4A per 100g.

So using the example above, which is more or less what I observed when testing, if I know I can maintain altitude at 7A, that means I'm needing 233g of thrust to stay in the air at 3A per 100g. If you need more amps to produce the same 233g of thrust, then your flights are shorter.

So sure, the second tested prop produced almost double the thrust, but was far more inefficient at doing the job. This is why I'm running a 9x4.5SF as it gave me the best efficiency rating for my motor.

I'm looking for duration in the air, not raw power.

The problem is that these are all static ratings and at full power too. The figures would be different if compared at 50% throttle and with the prop unloading at 40kph.Thoughts?
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Last edited by wingsnapa; Jun 17, 2012 at 05:52 PM.
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