Quad wont lift off...

H

hug_dealer :D

Active Member
Hey guys... first time i fired the quad up all is well.... but it wont lift off...

Using emax 935 kv motors with 10x45 props. (Yes they are mounted in the right direction!).

My battery is the 3s tattu 5100mah 10c lipo. Could it be the c rating (so there isnt enough current) i have 4x20A esc's so i assume i need 80a... whereas with this i have 51 amps... any battery reccomendations? Want one to have good flight time
 
Are you bound to rx & have Aux switches setup eg. Arm & modes.
Are endpoints set on both config tab in betaflight & in blheli config on the esc's.
Do the inputs work in the rx tab in betaflight. When move sticks do the ranges move.
 
hug_dealer :D said:
3s tattu 5100mah 10c lipo. Could it be the c rating (so there isnt enough current) i have 4x20A esc's so i assume i need 80a... whereas with this i have 51 amps..
Click to expand...

You use the motors, not the ESCs for your calculation. 51 / 4 = 12.75A each.

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Looks like plenty. What is the total weight of the quad?
 
Do the props actually spin & you just can't get it up? I'd check prop direction again it maybe pushing into the floor.
4 emax 2205 can pull a kg easy.
Just one lifts my 600g wing easy.
So should your setup. try a higher c rate but I use some 20C compared to 40-75 there is not a major difference.
Just a bit less bite.
 
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Here's a simple test, set the quad on a flat surface, put some corn starch under each motor, run the quad. If the corn starch blows out and around, you've got the props in the right direction. If the powder blows up or not at all, you've got the props on wrong. My granny taught me that for some reason or other.
 
Yeeeaaahhh Cowboy.
What if he wants or needs bigger esc's in future.
I got loads of spares but if I was going to buy any more I'd get 30amp as I'm wanting to try some 2306 soon.
640g per motor on a 1.2kg quad
Maybe the chart got lost in translation in Chinese & it wrong. Is that 640g at full throttle , mid stick is half of all 4 motors thrust, which about equals the weight.
Did the op get to full stick.
Somthing is fishy.
 
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Yeah if you flip any two of the three phase wires you will flip the direction the motors spin, it could be all of them are going backwards relative to what they should be, seems pretty unlikely but there's a 1/8 chance of having all 4 going the wrong way so it can happen. You can either swap two out of three of each motors phase wires or switch reverse the direction with the ESCs configuration tool (know it can be done with BLHeli configurator and the suite has more I don't know anything about KISS but imagine they have something similar to reverse direction).

Would just feel for if the breeze is in the air or on the ground like LoneRC said basically.
 
mozquito1 said:
Yeeeaaahhh Cowboy.
What if he wants or needs bigger esc's in future.
I got loads of spares but if I was going to buy any more I'd get 30amp as I'm wanting to try some 2306 soon.
640g per motor on a 1.2kg quad
Maybe the chart got lost in translation in Chinese & it wrong. Is that 640g at full throttle , mid stick is half of all 4 motors thrust, which about equals the weight.
Did the op get to full stick.
Somthing is fishy.
Click to expand...
Managed to get to full stick and quad started shaking. Motors are spinning righy directiom do maybe props? Also what c rsting do u reccomend?
 
You don't need high C rating to swing larger props. The battery isn't your problem. If it's just shaking, it's either 1 or more motors are rotating in the wrong direction or your props are on wrong. Can you post a pic of your setup
motor.jpg prop.jpg
 
Bad pid setting cause oscillation or shaking. Higher C rating does give more bite.
I can tell & feel the difference on a turnigy 20C to a 40-75C.
Like Renov8r say not really needed but will provide extra power if needed.
I only use 3S now for groundstation equipment
 
The C rating shouldn't be much of an issue just for lift off. The amount of torque or force the motor can drive with will depend on how much current can be delivered from the batteries when you get to that limit but unless you are already drawing 100A+ or whatever your batteries support they aren't the limiting factor. If the batteries are too low C rating you would basically cook them by drawing more out of them than their internal resistance is rated to supply. Drawing more from the batteries than they are designed for will cause them to overheat and possibly puff, if these aren't things you're seeing wouldn't suspect the battery.
 
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