X8 just use top motors for takeoff and Land possible?

Hey guys,

I want to build an X8 with the 7“ Armattan Chameleon. In this configuration, the tips of the lower motors would act as a landing gear. So it wouldn’t be very smart, if the lower motors spin during take off and landing. Is it possible, to shut off and turn on the lower motors by a switch for these sequences?

Thanks for any help :-)))

Yes, itis possible to disable some motors on a switch. But do you have enough thust to takeoff with only four motors :thinking:?

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Also; the lower motors will still windmill unless you have the option to configure a sufficient holding current.


Good point @Andre-K
More characters

@amilcarlucas Yes, it will be way overpowered and the extra 4 props are more or less just for safety. eCalc says, that it will be slightlier efficient - 2-3 minutes or so.

And how do I configure that? What’s the approach? Do I cut the pwm to the escs? Or is there an extra function for that?

Thanks :-)))

Isn’t there a function for the escs to „break on stop“? I use that for my planes for gliding, but with iNav. But I thought it was an esc Setting.

Thank you both for your answers and thoughts!

I‘m pretty sure, that a freestyle quad has brakes on motors for better and quicker response, no? I think, even if the was windmilling, it wouldn‘t be too bad, since the contact to the ground would stop them. So that‘s not a major concern :slight_smile:

What do you mean by „more characters“?

Even when you think you gave all information, there are still questions. Hehe.

So the whole project is gonna be a 4 arms X8 7“ longrange freestyle copter based on the armattan chameleon, carrying a GoPro 8.
X8 just for efficiency and safety reasons.
X4 would do an excellent job as well…

FC kakute H7 BT 50A Stack (incl. two Tekko 32 F4 4in1 50A)
T-Motor F90 1300 kv
Crossfire system (the big one)
Matek GPS & Compass M8Q 5883
Molicel 21700 P42A as a 6s1p or 2p (Test)

Total weight 1169g - so plenty of lifting power

All but the reason for doing it. What’s the problem with landings legs? I have used them on frames like that.

Well, I would have to design and print long spider legs to compensate for the narrow body. I also wouldn’t like the look of it. Weight is an issue, and it‘s a unibody. And I don’t want to drill holes in it.
Also, I like to think out of the box and the idea of controlling the motors and using them as a landing gear…

@Imme The ESC’s need special configuration to hold instead of just stop.
Stopping the propellers requires continuous power, (and produces heat)
Most ESC’s that have this feature does have “sane” holding power - not : “let me stop the propeller, regardless of 8cm above, there is another such propeller that works even harder that they both did”

When holding, the heat is not distributed evenly, and air flow thru the motor is reduced, compared to normal operation.
I suggest that you research ESC’s capability to hold “that strong” - or else - you will end up modifying ESC firmware yourself.
-you can start by checking out VESC or BLheli ESC firmware - maybe one already offer customizable breaking
-then you need to find out whatever it’s enough to stop it with the other motor running at much higher power. If you do get it it to work: post a video :slight_smile:

Hmm hmm I See, I See. Thank you very much, Andre. I will definitely do my best, since I would prefer them to fully stop. But windmilling would be ok too. As long as they don’t spin by themself.

I start ordering parts in two weeks, when I’m back home and then build it. So a Video may take a bit but I’ll post my result! Promise :-)))