Need Help! I just won't fly!

Ben Mac

Member
Hi guys,

I just recently got in to building drones and started my first build, I was 100% new at all this and rushed in with no real planning or thought, I new what I needed to get a drone to fly and that's about all. Now as the title suggests it won't fly.
For my school project I built a self designed 3D printed model. I am on a really tight budget so a hexacopter seemed the best design cause it was different and I found a good deal on motors. I bought a set of 6 DYS 1806-2300kv Brushless motors. 6 BLHeli 20 Amp ESCs. I'm running 6045 3 blade props and have a KK 2.1.5 HC flight controller. I have two batteries a Turnigy 3 cell 4000 mah
And a Redback 2200 mah 3 cell.
I have a PDB but can't remember which one. And am using a TGY i6s transmitter. After heaps of work cause I'm not the smartest at this stuff, I set up my drone, all the motors spun and I though I was going great, I programmed the ESCs and then I attempted lift off.
I got about 20 cm of the ground at 100% throttle. My drone weighs about 800grams so these 6 motors with these props should lift it easy! As I tested more to find out my issue I recalibrate my ESCs. I discovered two motors were spinning excellently, out performing all he other 4 motors, lifting almost half the weight on there own! The other 4 motors were performing poorly. Anybody have any ideas as to why I this is?
I did use a mix of both 60/40 solder and 50/50 which may be the issue but I have tried nearly everything apart from resoldering the lot and I can't find a single solution! Any help would be greatly appreciated! I'd rather not spend too much money but if I have to I will.
 


Ben Mac

Member
It weighs 800 grams
I can take another photo of the wiring too if that helps
 

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How hot are the motors getting. 6045 Tri props seem a little stout for those small motors but maybe

What I am wondering is if those motors are so overloaded that they cannot get up to speed to generate the trust you need.

How are you determining that 2 of the motors are doing most of the work?

Make sure your screws are not too long into the motor base, that could be causing problems if 4 of the motors are struggling. Depending on motor design, you don't always get a lot of room to run screws in.
 

Ben Mac

Member
How hot are the motors getting. 6045 Tri props seem a little stout for those small motors but maybe

What I am wondering is if those motors are so overloaded that they cannot get up to speed to generate the trust you need.

How are you determining that 2 of the motors are doing most of the work?

Make sure your screws are not too long into the motor base, that could be causing problems if 4 of the motors are struggling. Depending on motor design, you don't always get a lot of room to run screws in.

Thanks for the quick reply. I also tried the 5045 props with 3 blades which are the ones in the picture and they had the same issue.
When I was calibrating my ESCs two motors gave much more thrust than the other motors nearly lifting the whole weight! I calibrated them manually so each one was done individually, but exactly the same.
The screws were a huge issue for a while so at the moment the motors have an adhesive the holds them to the plastic, I did that to eliminate the issue.
 

Check your channel travel in the kk2, make sure when you throttle up that you are getting full travel (near 1900?), it is possible that your transmitter is only giving you 50% travel range on the throttle channel based on the manual esc calibration you are doing.

How are you doing the manual calibration?

Are you able to get into BLHeli suite to verify the programmed throttle points?

What version of KK2.1.5 firmware on you running? I think previous I was using 1.18 Pro by Steveis. If you were to upgrade to this version, you would be able to use the KK2 passthrough to calibrate ESCs if your current version doesn't have it.
 


Ian Kistler

New Member
Hi guys,

I just recently got in to building drones and started my first build, I was 100% new at all this and rushed in with no real planning or thought, I new what I needed to get a drone to fly and that's about all. Now as the title suggests it won't fly.
For my school project I built a self designed 3D printed model. I am on a really tight budget so a hexacopter seemed the best design cause it was different and I found a good deal on motors. I bought a set of 6 DYS 1806-2300kv Brushless motors. 6 BLHeli 20 Amp ESCs. I'm running 6045 3 blade props and have a KK 2.1.5 HC flight controller. I have two batteries a Turnigy 3 cell 4000 mah
And a Redback 2200 mah 3 cell.
I have a PDB but can't remember which one. And am using a TGY i6s transmitter. After heaps of work cause I'm not the smartest at this stuff, I set up my drone, all the motors spun and I though I was going great, I programmed the ESCs and then I attempted lift off.
I got about 20 cm of the ground at 100% throttle. My drone weighs about 800grams so these 6 motors with these props should lift it easy! As I tested more to find out my issue I recalibrate my ESCs. I discovered two motors were spinning excellently, out performing all he other 4 motors, lifting almost half the weight on there own! The other 4 motors were performing poorly. Anybody have any ideas as to why I this is?
I did use a mix of both 60/40 solder and 50/50 which may be the issue but I have tried nearly everything apart from resoldering the lot and I can't find a single solution! Any help would be greatly appreciated! I'd rather not spend too much money but if I have to I will.


When you did your calculations, did you figure for 50% or 100% throttle. Helped University student build a large platform quad and they did all their calculations at 100% when we hover at 50%.
 

Assuming you are getting the motors to spin up, each one should be producing at least 300 grams of thrust I would think, I didn't check those motors but just as a rough guess...but even if it was 250 grams, with 6 motors that would still be 1500-1800 grams of thrust. For a 800 gram drone that is not terrible to the point it won't lift off but would be under powered. Seems like when it gets away from ground effect it just has nothing left.
 
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Ben Mac

Member
Well I did my calcs for both 50 and 100 so it should be fine, which it now is. I hadn't set the throttle travel correctly on the KK, once I changed that it worked like a charm
 

Out of curiosity what did you adjust on the kk? I would have guessed it an adjustment on the remote but not familiar with all of the firmwares for the kk.
 



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