Aeronavics / Droidworx Droidworx AD-3 Specs vs. eCalc

[BrundleFly]

This may be idiocy on my part, but I would like a learned opinion from a kind veteran, if I may.

Got the Droidworx AD-3 Standard Lift frame and AXI 2217-20 motors, SimonK-flashed DYS 30A ESCs and plan to run it on one or two 4000mAh Turnigy Nanotechs, 4s, 25-50c. The last part is the only difference to the data entered below, the nearest option being "35/50c". Will hang an AV130 off it with a 200g point and shoot. AUW should wind up at 2.2kgs, max. Importantly, I was going with the recommended 11" Graupner props. These specs give me this:

(DISCLAIMER: I know it's not a hexa and that this calculation doesn't take into account the potentially lower power the co-axial config might imbue.)

View attachment 6719

Surely this can't be so. Yet it likes 10" props....

View attachment 6720

Am I doing something wrong, here? I don't wanna blow any(more) of this expensive higher-end equipment I find my evil other buying these days. I'm sure I must be missing something very simple, is all. The blurbs say 10 or 11 inch Graupners. WaddaIknow?

Cheers

 

[jes1111]

Ignore the second "C" figure - that's the burst rate (and as such more of a marketing claim than a reality). Select a 4000mAh 25C pack from the list - the lower C rating means the pack's voltage will sag slightly more under load - that should squeeze you in under the limit

 

[BrundleFly]

Thanks Jes. It does, at that! But when I choose 2x4000mAh batteries, it goes back into the red... I didn't think that would matter.

 

[jes1111]

Are you switching between one and two packs and adjusting the AUW appropriately? You have it set to "including Drive" so it won't automatically recalculate the weight as you have it. Best is to subtract battery, ESC and motor weight from your current AUW, then set that top line to that weight and "excluding Drive" - then you can easily change the number (or type) of packs and eCalc will adjust everything accordingly.

 

[jes1111]

Remember, too, that eCalc only claims to be accurate +/-15% (as one would expect for a straight mathematical calculation when there are so many real-world variables).

 

[BrundleFly]

Thanks. I tried your suggestion and it makes for interesting tweaks on the set-up, but all in all - even given the +/-15% margin for error - it seems to be cutting it too fine. Yet these are the recommended components for the frame. I reckon I'll run it on 10"ers first. Thanks for the input, Jes. I mostly wanted to check that I wasn't missing an important link in the chain. Now I feel more comfortable also inquiring with droidworx as to their thoughts on this.