Quad barely gets 1cm above ground

Hello Friends,

I made a custom Quad (X configuration) with light weight aluminum towel rods and thin wood sheets as a center plate. I am using the tilt camera mount from Hobby-King as a base.

I am using the following components:

NTM Prop Drive 35-48 Series 900KV / 815W (191 grams each with mounting and prop accessories x4)

TURNIGY TRUST 70A SBEC Brushless Speed Contr (65 grams each x4)

Slow Fly Electric Prop 12x4.5R SF

Slow Fly Electric Prop 12x4.5 SF

ZIPPY Flightmax 8000mAh 3S1P 30C - (2 batteries in parallel for longer flight) (644 grams each x2)

Camera Mount (195 grams)

and APM2.

The total weight of my quad after assembly is little less than 3000 grams (3 Kg).

I went through the step by step instructions and mounted the props in proper directions, calibrated ESC's and I made sure everything else is proper.

When I try to fly my quad at full throttle, my quad barely fly at 1 or a couple of centimeters above ground. I suspect it is because of too much weight????

How can I modify my quad so that I can fly it normally???

In the above image, the red arrow indicates the forward direction. I made sure that the black props rotates CW and green props CCW.

Just by visual inspection, does anything seem wrong? What else can I try to solve the problem.

Thank you all for your help.

Replies

• First of all, thank you all for your response. Yes, I will post some pictures.

But what is the math behind calculating the

1.) Thrust per motor in reference to motor current.

2.) Thrust and Weight relationship.

3.) Thrust and Throttle relationship.

This might be some dumb questions, but I would really appreciate some basic explanation.

Once again, thank you very much.

• Archit

if ur multicopter flying wt is 3Kg, and u r using 35-49 motors which use 800W of power.. then that motor is capable of producing 2,000g of thrust per motor....

so something seriously wrong,

lets assume a efficiency of 70%.. so each motor will give at least 1,400g thrust X 4 motors is a total of 5,600 g thrust... at flying wt of 3,000 u should be hovering at 50% throttle...

suggest u put up some pics ,, very close up pics of ur quad specially how u have mounted the props. ur motor is capable of 80amps .. to me it appears a massive over kill for ur quad ...