Hello Dear Friends

I've build an Hexacopter based on Tarot 680Pro frame.

The problem Is that It doesn't take off at all (80% throttle until it actually start trying to)

I've calibrate the Remote (via Mission Planner) and the Esc's and It looks like It doesn't have sufficient power.

The Electronics Specs of it are:

6* 5008-340KV Turnigy Motors

6* Afro ESC 30Amp Esc's (SimonK firmware)  - I didn't try to reconfigure it

1355 Carbon Fiber Propellers

4S 6000mAh 50C 100C/Burst

HML 650 Carbon Fiber Folding Legs

APM 2.6 Firmware 3.2 Controller

Some lite FPV+Telemetry+MinimOSD+3 AA Battries.

Total weight about 2.8Kg

What Can be the problem for it can't lift itself at all?!?

Thank you very much

Best Regards


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Your blades and battery may be undersized for the KV of the motor.

That motor can go to a 6s battery and drive blades around 17-18 inches.

You might try larger blades first.

Dear Robert

Thank you for your answer.

Currently my Tarot680 frame will only allow bigger blades if I'll turn around 3 arms 180 degrees.

So I'll have 3 motors up and 3 motors down (the blades should be all up of course)

The blades will not be level and I'll hope to find a blades that I can install upside down on this big motor surface.

If so. would some one can recommend me on this setup?

What are the pros & cons?

Thank you all

Hi! In which flightmode does this problem exist? In Stabilize or in Loiter or other Auto-Modes? Try it..

Please ask eCalc for your setup.

5008-340KV has 700W by single motor that is too much power for the 2.8Kg hexacopter.

And also there will be synchronization issue by mismatch of ESC, motor and battery.

It will easy by change of 5008-340KV(700W) to 300W class motors.

In Stabilize it looks like the worst problem.

In AltHold it actually started to take of for 2maters for 5 sec (but than I land it since the wind was very strong today.

What can we conclude from all of that? 


eCalc has gave me "Your Setup is unrealistic and way out of Limits!" (I didn't found my motor and pick Turnigy Multistar 350kv instead)

Yes a smaller motor (700kv) gave me realistic result but the motors is the last thing I'll want to change (cost and installation time)

BTW this Hexa is for a Delivery testing so I'll put 2Kg-4Kg load on it most of the time!!!

What should I change in order to have this Hexa fly and hover in 60%-70% trorrle?

*Flip 3 arms + 15 inch props? (what pitch is the best)

*Change Battery to 6S?

*Change Esc's to 40A-50A?

Thank you all you are helping me allot to clear the duets away

No, the question is whether the quad takes off at for example 50% Throttle.
Try to go up in stabilize and then, when you are at 5 meters switch to althold. This should work. Furthermore, take a look at the throttle_mid parameter and the tutorial at the arducopter-wiki how to set this up as best.

You're definitely using the wrong battery for that motor and prop size.  A motor that low of kV must use a 6S battery or larger battery.

Right now eCalc shows your build hovering at ~80% throttle (definitely bad).  Switching to a 6S battery brings hoover to ~56% throttle, but this adds a lot of weight.  

Really you want this to be closer to 40% throttle if you're planning on adding more payload weight (i.e. camera + gimbal), but it's not critical. 

If you want to stay with the 4S battery (I'd encourage this), I'd then suggest using the Turnigy 4225-610.  This will give you hover at 40% throttle while saving you a lot of weight between battery and motors while offering a flight time around 20min.

Thank you Phillip

If I'll replace to Turnigy 4225-610 motors (with the current 4S 6000mAh & 30A ESC's & 1355 inch prop's)

Would I be able to add a 2KG payload (or even 4KG?)

What flight time should I expect?

Based on a weight of 2.8kg with your current setup, just changing the motors will reduce this to 2.3kg.

Single 6000mAh 4S battery

With no payload (AUW 2.3kg): Hover = 20min @ 41% throttle

   1.0kg payload (AUW 3.3kg): Hover = 11min @ 50% throttle

   2.0kg payload (AUW 4.3kg): Hover =  8min @ 60% throttle

   3.0kg payload (AUW 5.3kg): Hover =  5min @ 68% throttle

   4.0kg payload (AUW 6.3kg): Hover =  4min @ 76% throttle

For comparison, if you use two batteries in parallel:

2x 6000mAh 4S battery in parallel (4S2P)

With no payload (AUW 3kg): Hover = 26min @ 48% throttle

   1.0kg payload (AUW 4kg): Hover = 17min @ 57% throttle

   2.0kg payload (AUW 5kg): Hover = 12min @ 65% throttle

   3.0kg payload (AUW 6kg): Hover =  9min @ 72% throttle

As you can see, weight makes a huge difference in flight time.  People who are flying for 40min+ do everything possible to reduce weight.

I would discourage any set-up that requires more than 60% throttle to take off.

Flight times may be slightly better if you spend a lot of time moving forward at a moderate-low speed while maintaining altitude.

These numbers were generated by eCalc.ch

I'm using 2814-710 motors driving Graupner 11x5s on a simiIar frame. I'm cheap, so I got RCTimer ones, even if it's sporting a $3k thermaI camera, but one can find them from Cobra, T-Motor, KDE and more.

The bird weights 2.1 Kg and has attached a ~ 1 Kg 11.000 mAh 4S pack giving 20 minutes of soIid fIight.

I didn't test, but a 2Kg payIoad is possibIe, with dismaI fIight time - expect 5-6 min most - but care shouId be taken about pack C-rating. 4Kg is a no-no unIess trying a 10-second beerIift :) 

340KV + 13"props + 4s do not fly :D 

 I suggest you put 16" props, if necessary just alternate mounting your motors one arm- top another bottom, this way you can fit 15"-16" props on hat frame no prob. 

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