I'm building one just for ArduPilot, and starting with brushless..
I have a Castle Phoenix-25 and Meag ACn 16/15/4 (2200kV) motor.
I ran an APC 6x4 Electric Pusher prop on the bench, and it's hitting 28A on a 3S battery. That doesn't seem good. I dialed the ESC down to mild (0) motor timing, and it still went to 27A. It moves a lot of air, but the ESC will quickly overheat if it's tucked away in foam.
I tried an APC 5.5x4.5e pusher prop, and that seems to cut the current down to size.. 22A at peak.
I know static (bench) current is different than flying current, but I'm wondering if most people are running 6x4 and getting away with extended full-throttle?
Is my ESC undersized? Are you mounting it outside the foam for cooling? The motor is only rated for 25A anyway. I don't expect I'd be running it flat-out much or at all.
Really, I'm looking for the "most efficient" setup in terms of distance for mAh. I don't mind if the peak power is lower, if it means longer runtimes overall.
Any idea if a 6x4 at reduced throttle is as efficient as a 5.5x4.5 running faster?
Am I overanalyzing this?
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It's clear that the ESC is going to need free-air cooling. It heats up fast.
I'll fly the 5.5x4.5 prop for now, ESC external, and order a bigger ESC if I need more power. I'm guessing this will be plenty of Go for UAV flying.
Once I get all the UAV goodies together, I'll get a dedicated CC-BEC for them. Seems like it's worth measuring too. A pair of Hitec HS-64HB working overside control surfaces non-stop.. doesn't leave much for computing and video.
Thunderbird 36 is $43, with a 3A BEC.
Phoenix-35 is $85 with a 3A BEC
Phoenix Ice Lite 50A is $85 with a 5A BEC
The CC-BEC is 10A for $22.
So it looks like CC-BEC+Thunderbird or Ice Lite 50A is the way to go. Maybe there's something to be gained from keeping the servo power separate from the UAV/XBee/Video power?
A better prop for the /4 in the EasyStar is the 5.1x4.5 if you can find them. It has rather more curved blades with much more blade area. If not, then the 5.5x4.5 is probably going to be better for you in the long run.
Whatever you do, don't bury the ESC in the foam. Particularly if you aren't going to use a separate BEC - the autopilot will work your servos much harder, meaning more load on the 5V supply. Cooling is very important.
When I use a 6 X 4 APC prop with my 2200kv outrunner on my EZ* I use a Thunderbird 36 ESC and it works fine. Your CC Phoenix 25 will not cut it unless you go back to a 5.5 X 4.5 prop.
Just a thought.
Regards,
TCIII