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Help! Spruce Gosling by FoamyDM

What should I name this project?

  • Bloody Goose (no Change)

    Votes: 0 0.0%
  • Pop-top Goose

    Votes: 0 0.0%
  • Pop-top Gosling

    Votes: 0 0.0%

  • Total voters
    6
  • Poll closed .

Mid7night

Jetman
Mentor
#21
This project looks awesome! I love multi-engine designs, especially of big planes like the Spruce Goose.

That said, I hate to be a wet blanket, but I need to point out the very serious concern I have with your intended setup of running two motors from one ESC, times 4.

I have used HD servo wire for the motor leads without problem (see my B-52), HOWEVER: You really should use one ESC per motor. I did some quick searching, this question has been asked many times, and while it has been shown to "work" - that is, using one ESC to power two motors simultaneously - it is not in any way efficient or reliable, and could result in frying the ESC altogether.

Obviously I know cost is a concern here, but I'd rather see you wait while you save up some money and get the ESCs to do it right, rather than let it go and watch you smoke the four you have.

If you only need the power of 4 motors to fly, you could just power the inboard 4 motors and let the outboard pairs freewheel.
 

FoamyDM

Building Fool-Flying Noob
#22
Thank you @Mid7night I will put more on order... It makes sense, that the spike Amps (which can be high) would be Doubly high.

I will be using a 2S battery to start (and see if the plane moves.) I have a 5000 Mah 2S for RC cars I was going to use.
I will make a promise that I will not attempt a 4S run on 4 ESCs unless I am done having fun with the current model and am looking to potentially fry the ESCS...

or I will test them well before field use on 4S.
 

FoamyDM

Building Fool-Flying Noob
#23
last night I did a couple tests of the electrical system for this project and found that it's not as successful as I wanted which is not a big deal and I think I just need to put in the ESC on each individual line. which means midnight 7 is right. Time to wait for some low-cost escs

Electric system update: nothing successful. I divided the split servo wire from the ESC so it's just one line. Same thing. Worse with other escs.... :cautious:.

Quite dismaying.

ElecLayoutDiagram.PNG
 

FoamyDM

Building Fool-Flying Noob
#24
Does anyone know how to test that an esc is working right?
I'm not sure my 30a ESC work right at all. and I have 4 more on the way.

After looking around un-surprisingly I found this on the topic of two motors, 1 esc...
"Very bad idea - don't do it !

Brushless ESC's are not like the brushed ones, brushed controllers are dumb and just output pulses to spin the motor(s).

Brushless controllers are active. they listen to the motor so that they can time the next pulse - this is how they work. if you have two motors the timing will go out and you will have a fire !


if you want two motors, use two controllers (ESCs) and parallel the radio wires and battery wires, then disable one of the controllers BECs."

I have a number of 12A escs on their way and will be perfect for a 3S situation. right now, that's my plan for this project. as it stands the are being processed in china distributing post.