Problems with First Quad Build, Can't Take Off Without Full Throttle

[alm865]

Hi All,

I've been stuggling to get my Quadcopter up in the air for the past two months and need some help. It's a long story so I'll try to keep it short!

Basically I started with a F450 frame, A2122 930kV Motors, 1045 Props, 30A ESC's, KK2.1, 3S 35C Lipo Battery, and a 6ch Tx-Rx.

When I put it all together I had issues calibrating the ESC's, bascially the instructions were in chinese but I managed to find someone to translate them for me and they are all good now. The ESC's are calibrated to the flight controller and they all startup at the same time.

So my first few flights were pretty bad, three props down and it still wasn't stable. I tweaked a few PI settings on the KK2.1 and it's now getting airborne but I need full throttle to actually get off the ground and it really stuggles to balance because it's using all it's power to keep it in the air.

My first thought was that I was overpropping the motors, so I bought 8050's and 9050's props to test, the Quad doesn't even budge off the ground with the smaller props at full throttle.

I've since checked that the throttle is actually sending full throttle to the KK2.1 (i.e. 90), ESCs are calibrated to the KK2.1, Motors are spinning in the correct direction (i.e. it actually does take off but only at max throttle), only the first ESC power is connected to the KK2.1, props are tight and aren't spinning on the motor shaft (no evidence of scoring/rubbing either), and heaps of other stuff.

I've ordered gear to flash the ESC's with SimonK firmware (yes I know what I'm doing ;-) , and I'm going to flash the KK2.1 to the latest version too. It's going to be a few more weeks until they arrive though.

My Quad is pretty bare, I have nothing extra on the frame, it's basically all motors and battery.

So does anyone see anything obviously wrong with my setup? Everything seems okay, motors/ESCs don't get hot, battery charges okay... Why can't I get off the ground without full throttle?

 

[alm865]

Nobody has any suggestions?

Are 930kV motors on a 3S Lipo battery fast enough for 10" x 4.5" props? I was thinking of getting 1200kV motors to see if that helps things.

In a few weeks I'll have flashed my ESCs with SimonK firmware and have the latest KK2.1 firmware (like I said, waiting on bits)... Any one else flashed with SimonK? What's the before and after like?

 

[alm865]

 

[GJH105775]

930Kv is usually 12'' props. I am using 1400kv for 9'' props, but that is really pushing it. If you want 10 then I'd get 1000kv. You should be able to just buy bigger props if your frame will allow it. You can also adjust throttle limit and scaling up, but you can burn your motors doing so.

 

[GJH105775]

If you post a new thread and are looking for a quick answer you can also pm Me or someone else for example Holtneil. Usually forums are answered a little faster, but I missed this one in the new post. SimonL makes throttle and other things more smooth ((less jumpy or jittery). Here is a basic static thrust calculator. Can you provide a link for your motors? I am guessing your frame could handle up to 17'' props, but your motors around 12- maybe a little higher depending on what motors you have.

4.5'', 4.7'', and 6'' are the pitches you can choose from. Depending on what your motor will handle, the higher the more thrust and speed.

 

[alm865]

Hmm, 12" is pushing it but I might be able to fit them. It might be easier for me to get 1000kV motors though since I'd prefer agility over stability (I've heard big props can be sluggish at accelerating).

My motors are cheap ebay A2212 930kv (I think they are knock offs of another brand...). I've got heaps of spares, I swapped out a few I thought were getting warm but it made no difference to the lack of lift. I have no way of confirming that they are indeed spinning at the proper speed though. I may be able to test lift since I've got a spare dodgy arm with an ESC and Motor already attached, I won't be able to do it until Sunday though, even then it'll probably be subjective since the prop will be in ground effect.

According to the calculator link above to I should get about 1.2kg of lift per prop, I can't remember the exact weight of my craft including the battery but it was around the 1kg mark (something like 800g?) so I should be able to easily lift off at full throttle but it's struggling at the moment.

Ah okay, I think it's a good upgrade going with the SimonK firmware anyway, I've already spend about a week trying to match my ESC with the pics to work out exactly what model I have... I'm just waiting on the programmer then I can Flash away!!

It's all good, I've been watching the forum over the last day and there are heaps of posts, mostly about the same things. I can see how some are missed.

Thanks for the reply

 

[alm865]

Also is the KV rating really that sensitive that a 1000KV motor will work with a 10" x 4.5" prop and a 930kV won't? I didn't know that was the case...

 

[alm865]

Okay, bought three sets of 12" props from China... The waiting game begins again...

 

[GJH105775]

Haha, they did not even bother to knockoff any other brand. Also the description says 1000kv and the picture 930.

Here are some relatively cheap motors that are 1100kv.
Too pricy, there are cheaper ones here
Here are the test:

Prop Tests: 8x4 - 14.8v - 251W - 17A

8x4 - 11.1v - 121W - 11A
9x6 - 11.1v - 178W - 16A
9x6 - 14.8v - 355W - 24A
10x5 - 11.1v - 200W - 18A
10x5 - 14.8v - 385W - 26A
11x5.5 - 11.1v - 200w - 20A
12x6 - 11.1v - 266w - 26A


​

 

[holtneil]

Hi mate had really cheap 2212 1000kv on a F450 with 10x4.5 props and a 3 cell 2200mah , its a rocket and flies for about 10/15 mins till the kk cuts off
As for flashing the kk wants steveis1.8s1pro its really nice and the esc are much better with simonk flashed watch this

 

[alm865]

Hi mate had really cheap 2212 1000kv on a F450 with 10x4.5 props and a 3 cell 2200mah , its a rocket and flies for about 10/15 mins till the kk cuts off
As for flashing the kk wants steveis1.8s1pro its really nice and the esc are much better with simonk flashed watch this

Wow, that's an impressive difference. I've got a bit more confidence now that flashing the ESCs might actually fix most of my issues. I almost bought some 2212 1000kV motors the other day, I told myself to stop buying stuff until I have flashed everything, I've already bought enough for about three quads trying to get this thing in the air :-/

Yeah I did see the Steveis firmware for the KK, I read somewhere that it was more stable and more responsive.

Still waiting on the programmer before I can flash anything. Should have just spend a few extra dollars and got one from Australia, China and Hong Kong are soooooo slow sometimes.

I will post back once I've flashed everything. I'm kinda in limbo at the moment waiting on parts...

 

[alm865]

Haha, they did not even bother to knockoff any other brand. Also the description says 1000kv and the picture 930.

Here are some relatively cheap motors that are 1100kv.
Too pricy, there are cheaper ones here
Here are the test:

Prop Tests: 8x4 - 14.8v - 251W - 17A

8x4 - 11.1v - 121W - 11A
9x6 - 11.1v - 178W - 16A
9x6 - 14.8v - 355W - 24A
10x5 - 11.1v - 200W - 18A
10x5 - 14.8v - 385W - 26A
11x5.5 - 11.1v - 200w - 20A
12x6 - 11.1v - 266w - 26A


​

Thanks for the info, I think I better cool my spending until the rest of the stuff that I've ordered comes in. I've got a USB programmer, and 12" props coming, the USB programmer should be here any day now.

 

[GJH105775]

Thanks for the info, I think I better cool my spending until the rest of the stuff that I've ordered comes in. I've got a USB programmer, and 12" props coming, the USB programmer should be here any day now.

I am in the same boat as you, waiting for my UAB asp I ordered a few weeks ago to flash my KK and ESCs I ordered a run cam 2or3 days ago and it may get here first xD

 

[holtneil]

Hi I am just glad the quads fly faster than the shipping

 

[alm865]

Okay!!!

I got all four ESCs flashed with SimonK firmware with avrdude. Super easy on linux, I just ran 'make all', then used avrdude like this 'avrdude -c usbasp -p m8 -U flash:w:tgy.hex'. Worked awesomely!! It's a huge difference from stock firmware. In hind sight I should have used kkMulticopterflashtool, but the way I did it was pretty easy anyways...

I got the flight controller flashed with the latest Steveis firmware (1.19 or something like that...). kkMulticopterflashtool was indispensable for flashing the KK2.1!! I literally just ran the program and pressed go and it worked!!

I did end up buying 12" props too, also a good choice, fits the F450 frame quite well despite my fears of the blades fouling.

I just have to tune the flight controller now, I did try and take off on cement and nearly snapped a prop (just broke 'the tip' for all those Archer fans out there...).

Looking very promising, it's got heaps more power, unfortunately I have to work at the moment so I won't be able to fully test until this afternoon.

Thanks for all the help guys! Won't be long until I'm up in the air with the rest of you

 

[GJH105775]

Nice and neat build. Yeah, I made the mistake of testing on concrete a couple times and hopefully won't anymore. Broke props faster than the motors could spin up haha.


Did you have to use Wine or a VM for Linux? It is supposed to run naively. I run a heavily modified Debian based system.

 

[alm865]

It flies!!!! Quite well too!

Turns out one of the props was spinning backwards. Just changed the motor direction in the SimonK firmware, recompiled and flashed and everything is sweet!

Didn't use a VM or Wine, the kkMulticopterFlashTool runs on Java so I guess it's kinda the same as native.. sorta... Just download the latest version, gotta open up a terminal and 'chmod +x kkMulticopterFlashTool_64.sh' before you start then just run it by './kkMulticopterFlashTool_64.sh' and bang it works! You don't even need to download any Firmware files, it does it all and gets the very latest versions from the looks of it! Super easy, the USBAsp was recognised automatically, no mucking around with drivers, just plugged it in and it was ready to go almost instantly. Just double check it's working by typing 'dmesg' in the terminal as soon as you've plugged it in to see if it's recognised.

Really happy overall, just need to buy a few more spare props because I'm gonna be chewing through them ;-)

If I build another Quad I'm definitely going to get ones pre-flashed with SimonK and update to the Steveis firmware straight away. The difference is incredible!

Thanks again

 

[alm865]

I probably should tell everyone exactly what I did for anyone in the same boat.

I bought a USBAsp from ebay, in circuit programmer for the ESCs from HobbyKing, and a 10-6pin adapter from ebay for the KK2.1.

I downloaded the latest SimonK firmware (tgy-master.zip, see Download as Zip button on right had side), and extracted it.

I'm using Ubuntu (Linux) and just typed the following in a terminal (from the tgy-master folder that is)

• sudo apt-get install avrdude
• make all (or maybe it was just make, can't remember)
  
• avrdude -c usbasp -p m8 -U flash:w:tgy.hex (or which ever hex file you need to use)

If you want to reverse the motor direction simply change this line in tgy.hex:

'.equ MOTOR_REVERSE = 1 ; Reverse normal commutation direction'

and recompile using 'make all' then flash again.

If anyone has trouble compling the SimonK firmware, here are some compiled versions (you really only need the .hex file for your board, check here, here and here to find out what ESC you have and what .hex file you need)

Pre-compiled SimonK Firmware (use at your own demise!!!)

Now for the KK2.1 flight controller, simply download the latest version of kkMulticopterFlashTool here or here (I used the second link), extract it, in a terminal type 'chmod +x kkMulticopterFlashTool_64.sh' or in properties make it executable, then run it with './kkMulticopterFlashTool_64.sh' (or you can double click on it and select run).

Then it should automatically detect your programmer, select the firmware you want, and press the little green man to run on the right hand side about half way down... done!!!

That's literally it, didn't need to install drivers, or anything else, just worked. The only issue I can see people having is if they don't have Java installed.

Really happy with how easy everything was, there is an impressive amount of work done on the SimonK and Steveis firmware. The kkMulticopterFlashTool was really impressive, my experience with microcontroller flashing tools has been pretty bad, to have a program work on the first go without tinkering or installing anything extra is really nice, I've never had that happen before! Not even the Arduino software is that good, you usually have to tell it what board it is and what COM port it is on, and that is one of the better ones I've used!

 

[alm865]

Also a word of caution, don't go randomly flashing your ESC with whatever hex file, you need to be 100% sure the picture of your ESC matches the pictures in the links above exactly! Any difference at all at you could blow up your ESC and possibly your battery if you don't have another power supply. I used my car battery just in case something went wrong.

Also just because you bought four ESCs from the same seller on Ebay does not mean they are the same. I bought 12 ESCs off eBay, same seller, they all looked identical from the outside but under the heat shrink one ESC was different to the rest and wouldn't flash, so beware...

KK2.1 is not quite as risky, everything is pretty fool proof there...

 

[GJH105775]

Thanks for the post. My USB-asp is slowly moving here.... err I think, because the Swiss Post tracking numbers never work. Also I have a bash script that I am working on for when you first install a Debian based system, in hope of avoiding you installing things as you need them for months after every clean install. Just message me if you'd like to see/use it.


EDIT:

Just got here haha.