Guys,

I have been working on getting the biggest prop I can on my new Excitation and have tested the APC_E 12x6 cut to 11 1/2x 5 3/4. This prop pulls and has an effective pitch of 7 @ 8600rpm. Problem is it also was pulling 54.5 amps static which is just on the edge of my A123 3s2p 4600mah pack. Well I did a little work on the back of the blade from the hub out about 2 ". There is a rather deep cup in this area with the trailing edge kicked up. The center of the blade adds very little to the pulling power of the prop and for the most part is just there to hold the outer half of the blade to the hub. This area needs to be streamlined and smooth. I sanded the trailing edge in this area to knock off this edge, it is only a small strip about 1/8" wide that gets sanded flat (not the whole trailing edge). Smooth off the edge top and bottom to remove the sanding flash and then wet sand with 600.

Result was the prop now pulls 50.5 amps at the same 8600 rpm. For me this is great and allows the full flight time.

Best,         Dennis

Hi Dennis,
My discovery has been that sometimes a narrowed prop will draw less current on the ground and almost eactly the same in the air. This has typically been in cases where I did exactly the same thing you did, by carving off the root trailing edge in a straight line from the knuckle in the APC prop to the mid span. in the wet series they used to sell a "butterknife" profile that did much the same.

Are you running at "idle" for the 30 seconds it takes to get to the handle? If not, then the change you made sure does save battery, as static current under governor mode is typically 140% of the flying current.
later,
 Dean P.