Quad wont lift

Hello!

I need your help please.

I have SK450 with Deadcat kit + Gimbal Tarot 2D + Gopro 3 Black

APM 2.6 with Fatshark 250mw kit + 915 telemetry kit.

Motors Turnigy D2836/11 750KV

ESC 30A, Simons flash.

Battery NANO Turnigy 4000 3S up to 90C discharge rate.

Weigt about 2-2.2kg (with battery)

And i've Got Etype Carbon Fiber 10x5 propellers.

And Quad wont lift off the ground.

I try to put Slow Fly cheap plastic 10x4.5 - and lift up with very high throttle.

What changes do u suggest for my current project so I can fly easy with full load weight.

Thanks,

Norm

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Replies

  • Thanks Michael!

    I found this awesome motor for regular drive: SUNNYSKY X2212 Brushless Motor 980KV but it also might not work for heavy lift.

    I try to play with ecalc - different batteries, motors, propellers.

    And so far looks like my Turnigy D2836/11 750KV with 11x4.7 or maybe even 12'' propellers would be the best. But I notice comments - bigger props got more vibration.,

    What would be equivalent to my engine in smaller props - any idea?

    Ans I'll go with carbon/nylon propellers.

    SK450 Deatcat kit for heavy lift will not work as well because I'm not able to put 12'' propellers - thats why i need to stick max with 11' or, get new motor with more kv & less propeller or change back to stock SK450 frame with less room. Or maybe get the new frame, but now I have another problem: I want something universal - i like fast and aggresive fly like 450 frames are getting really acrobatic, but also I want sometimes to use as areal filming with gimbal and gopro.

    Any suggestion for multi purpose frame?

    Thanks

    • Hi Norm,

      You have to find out what is the thrust of the motor (combined with the prop), and also depends on the battery 3S vs 4S

      For example, my Hexacopter is a DJI F550, I am using NTM Prop Drive Series 28-26A 1200kv motors, with 8x4.5 props, and a 5000 mAh 4S battery... the total weight it should be between 2 to 3 Kg

      Researching on the net, one motor gives 990 grams thrust (at max speed) (with 8x4.5 props, and 4S batt). So times that 6, that's close to 6 Kg thrust (rounded up), and so it makes sence when my drone lifts of at about 40% throttle...

       

      You have to do similar calculation.... so with your 2 Kg quad, you need a simmilar thrust (about 1 Kg), this way you get 4 Kg total thrust so it will lift off at half throttle

       

      The SUNNYSKY X2212 Brushless Motor 980KV motors gives 870 grams for your 10x5 propellers and 3S battery; this will probably lift off your quad, but I am guessing at around 70% thrust...  so you need a motor with a little more thrust.

       

      PS. The motors that I use have very bad bearings, and I read other people posting on the net have the same problem with this motor, so I don't recommend it. When I have more money, I will be searching for a better quality & equivalent motor.

  • Anybody?

    • OK, since nobody is replying.... first of all I am no expert; I am still struggling with my Hex...

       

      I think for your 750KV motors you need bigger props, maybe 12 inch?  or... get motors with higher KV, probably between 900 and 1000 KV...

      But... if you check the HK comments on the motor, there is one that says "the max thrust is achieved with 3S (11.1 V) and 9x6E propeller", this is contrary to what I learned so far, because I always thought that with lower KV you need bigger props, and higher KV motors you need smaller props; and that actually makes sense...

       

      On my Hexacopter I am using 1200 KV motors, and with 8x4.5 props, and I get lift off from about 40% trottle

      By the way.... just for testing, dissable barometer/altimeter when you take off because I made the mistake once to enable the altimeter at the same time I arm the hex, and it did not lift off because the altimeter was actually overriding my input to keep the Hex at the same height it started... and that was... on the ground!! LOL... so I learned that I actually have to take off, then after a certain height, then enable the altimeter... 

      • Thanks for answer ;) 12'' most likely will not fit. But I order 11x4.7 carbon/nylon and should be fine.

        Which motor in a range from 900-1000km do u recommend?

        I looked at ecalc and my motor with 1500g weight and 9x6E propellers - result (The airflow at the propeller blade will stall. Therefore a calculation for hovering is not possible! Reduce the propeller pitch.)

        • By the way... I did a quick search on what other ppl use for your frame, and I found this:

          https://www.youtube.com/watch?v=F3uHAJunC9o

          If you look in the info / about (click on "Show more"), they use Turnigy D2836/9 950KV (the same one I suggested a few mins ago), and lower in the info, they say "8x4~10x4.5 Prop"

          So it looks like the 950KV is the one for your frame...

        • Well, I don't think you should place your order based on what I said, after you get your order, and replace motors, if it's still not working, I don't want to be blamed for it, LOL.... as I said before, I am no expert, I just started into drones also... and it just hapened that I chose the correct motor/props combination :)

           

          Anyways... I took a second look at your motor, and it says "Prop size: 7.4V/12x6 11.1V/9x6", so with your 3s battery and 10x5 props, theoretically it should lift off... do the motors get hot?

           

          As for higher KV motor (for your 10x4.5 props), maybe this one: http://hobbyking.com/hobbyking/store/__18968__Turnigy_D2836_9_950KV...

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