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Help with V Tail quad !! issues with lift off and flying

#1
Hi Everyone

Im new here but i have been lurking around the forums looking for answers but cannot seem to find any.
I have just finished building a V tail quad just like Davids but i have used a little different specs on motors and ESCs.
i got - KK2 board, Hobbyking 30A ESC 3A Ubec and NTM prop drive 28-26 1100kv/300w short shaft. And im using a HobbyKing 2.4Ghz 4ch Tx RX v2 and im using 8 inch props on all fours.

I really need help with this as i have searched the net and all around, but still having issues on the quad not flying straight or NOT hovering in one place. It tends to drift to the left. I have used the same specs that is on David's V tail quad scratch build. stick scaling, motor mixer, PI editor, whatever needed to be done has been done and tuned to the same specs David uses. And my KK2 is still on the 1.2 version
Please Help!!!
 

xuzme720

Dedicated foam bender
Mentor
#2
First thing with drift is to check that the board is calibrated with the copter on a level surface. Also, check with receiver test that all channels are zero with sticks at neutral (throttle all the way down), and that you are getting about 100 at full throw. Adjust your radio's subtrim to zero the channels and endpoints on your radio if you aren't getting 100 at full deflection. If you still get drift, check that the front motors are level and the rear motors match each other exactly. Also check that the copter is balancing at the KK2 board. Move your battery around if it isn't.

And since you are on 1.2, don't use the autolevel.
 
#3
i have done those things, but it still drifts hard, i want that nice hover as soon as it launches. im not even using autolevel at all.
i even tried to calibrate the ESCs with the kk2 board just now. ANy other settings i need to do?
 

xuzme720

Dedicated foam bender
Mentor
#4
Are you in an open area? The rotor down wash can do funny things to stability, especially in an enclosed area.
However, since you are getting a constant one direction drift, I would look for the mechanical stuff(so to speak) like alignment of motors and balance laterally. Are you finding any of your ESC's or motors getting hot? That could be another sign of one set of motors working harder than the other to offset some factor you are not seeing.
Some video might help us diagnose your issue a little better. Right now we are just shooting in the dark...
 
#5
hi ,
I'n no expert on this. I startet with my tricopter 2 weeks ago. Had massive drift-problems in the beginning too.
I used auto level... upgraded firmware on kk2 board to 1.6 and things started to get really smooth ... perhapes it's worth a try
 

Johan

Senior Member
#6
Here is a nice video tutorial about the self level settings and adjustments you can make:


This guy takes the time to explain and show you the possible corrections
If you are in a hurry and want to skip the general description and flashing to 1.6 part, go to around 6:30 in the vid

The part before that contains some good explanation what Auto level does and also what it does not:
don't expect position hold or something like that, that is not part of Auto-level :)
 
Last edited:

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#7
Azkikr,

If you're in acro mode, the multirotor needs to be flown -- it won't fly itself. If you have autolevel on, it'll seek what it thinks is level, but even then it's not going to cancel momentum or hold altitude.

You see David, Chad or Bixler pop up and hold a hover and it looks like the board does everything for them -- it does a lot but not everything. You rarely see the sticks to see how much or how little they have to do. It's very doable, and very learn-able, but you have to learn to hold that hover with just a light touch.

To make it easier . . .

- flash 1.6 and turn on autolevel -- yes it's a crutch but it will really help you get the feel.
- fly with *LOTS* of open space until you get the feel of it.
- turn *DOWN* your stick scaling. this will limit what the throw is on your radio. hard left isn't as hard over as it used to be, and full throttle won't launch it into orbit anymore -- as you get better, start turning it up again. until you feel got good throw, and you're spending almost all of your time in the center.

*IF* you're still worried somethings wrong with your copter, set it on a flat table, and measure the distance from the prop to the table on each prop at the four cardinal positions(ok, left, right, forward, back instead of N-S-E-W). while each prop might be different, each measurement should be the same on one prop, otherwise, the prop isn't level with the table. If the table is level and all the props are level, run the ACC calibration again. After that any drift is offset in your TX, or you're doing it yourself.
 
#8
Thanks - Xuzme, ill make a vid in an open area and post it up here


Are you in an open area? The rotor down wash can do funny things to stability, especially in an enclosed area.
However, since you are getting a constant one direction drift, I would look for the mechanical stuff(so to speak) like alignment of motors and balance laterally. Are you finding any of your ESC's or motors getting hot? That could be another sign of one set of motors working harder than the other to offset some factor you are not seeing.
Some video might help us diagnose your issue a little better. Right now we are just shooting in the dark...
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#10
Can't open the link where I'm at right now, but any working USBasp devise should do -- it's a really common programing tool used by electronics hobbyists.

Just make sure you pick up the 6 pin adaptor, if it's not included. The standard connector is an 8 pin, and won't work without a little re-routing. If all else fails, you can build your own adaptor, but it's easier/cheaper to buy one ahead of time, in most cases.

BTW, when you get it, unplug your ESCs and recever before you connect up the USBasp -- Having them connected durring re-flash has caused brownouts, and a brownout durring a firmware flash will usually brick the board.
 
#12
Dan, thanks for the info and support all you guys are awesome and look out for members. I appreciate all these advice. Dan can you guys send me a link on where i can download a reliable 1.6 FW upgrade?




Can't open the link where I'm at right now, but any working USBasp devise should do -- it's a really common programing tool used by electronics hobbyists.

Just make sure you pick up the 6 pin adaptor, if it's not included. The standard connector is an 8 pin, and won't work without a little re-routing. If all else fails, you can build your own adaptor, but it's easier/cheaper to buy one ahead of time, in most cases.

BTW, when you get it, unplug your ESCs and recever before you connect up the USBasp -- Having them connected durring re-flash has caused brownouts, and a brownout durring a firmware flash will usually brick the board.
 

Craftydan

Hostage Taker of Quads
Moderator
Mentor
#13
Dan, thanks for the info and support all you guys are awesome and look out for members. I appreciate all these advice. Dan can you guys send me a link on where i can download a reliable 1.6 FW upgrade?
Glad we can help!

LazyZero's Flash tool: lazyzero.de/en/modellbau/kkmulticopterflashtool

nice little tool -- will pull up a current list of his repository of accepted KK2 and ESC roms, link to each rom's homepage/thread for you to review, download whatever rom you've selected, and flash it to the board.

Rolf's (the KK, of KK2) 1.6 version is a good rom, however there are a few other options worth investigating. I'm currently enjoying 1.6++, rev1 by RC911 for a traditional receiver -- It has all the upgrades of 1.6 plus many new features. The linked threads in the flashtool can fill in the details.
 

Johan

Senior Member
#14
Can't open the link where I'm at right now, but any working USBasp devise should do -- it's a really common programing tool used by electronics hobbyists.
Just make sure you pick up the 6 pin adaptor, if it's not included. The standard connector is an 8 pin, and won't work without a little re-routing. If all else fails, you can build your own adaptor, but it's easier/cheaper to buy one ahead of time, in most cases.
Dan is right: Make sure it has the 6 pin ribbon cable as well, I bought the wrong programmer (USBISP instead of USBASP), although it was advertised as the same, but it almost fried my KK2 (messed up the fuse settings).
Luckily kkmulticopterflashtool also has an option to fix the fuse settings, if it would ever happen to you there is an option to fix it, provided you have the correct flash tool.

Not trying to scare you, the tool look Ok :)
 

xuzme720

Dedicated foam bender
Mentor
#15
I think it's the same one as I have, but mine was only the 8-pin adapter, not the 6-pin. Just double check that the pinout is the same as what you need. I had to do my own adapter so it was easy to make sure.
 
#16
Dan, Johan and Xuzme720, i thank you and appreciate all your advice, i have not been messin around the Vtail yet, but i think i may have managed to calibrate the ESCs using the 1 and 4 buttons on the KK2. I have just ordered the USBasp so i will wait for that and upgrade my firmware.

thanks guys !! atleast i know i am not alone here
 
#20
Guys!
i flew the drone few days ago and it started to go forward and corrected it and so started to left and i got a bit nervous cos it went up high, i was happy atleast i know it flies :) i just need abit of practice. so i killed the throttle and it dropped and its a good thing the landing took the impact and broke. But everything else is fine. Dan i got my USBasp so i will need your help when it comes to updating my KK2 to a 1.6, i hope that will help stabilize my drone.