I just love building these flying machines. Here is my latest, a mini tricopter using the CC3D board.
I initially had an issue with the servos which would drift off center all the time. I couldn't even get it off the ground without it going into a wild spin, servo would just kick left or right. Researching this, I found that it could be a reversal issue, either in the software or the tx, or both, but this did not solve the tail wagging problem.
This no doubt will help a lot of people. What you need to do is zero the " i " value in the yaw PID setting. Do this for both rate and stabilize or attitude mode rather. This completely eradicated the problem and it is now 'locked in'.
I decided to power the servo from the UBEC and not from the CC3D board. The signal wire only is plugged into port 4. CC3D is powered from the Rx which gets its power from the UBEC. The servo actually gets its power from the a spare Rx channel because it is a common rail. This elimanted having to splice into the cable from the UBEC in other words eliminating a Y-harness.
This setup functions perfectly.
Some specs. The craft weighs 392 grams with the battery.
Frame: Pine and G10
Battery: 1300mah 3s Tattu Lipo
Fc power supply: ZTW ubec at 5 volts
Escs: ZTW 18amp opto without heatsink or capacitor
Motors: DYS 2300kv
Props: 5x3 Gemfan
Tail servo: Savox SH0254 metal/nylon gear
A couple hundred small zipties
Accessories: Low voltage alarm
Flight time: 6-8 minutes.
Without much tuning, she is flying very well. Absolutely locked in and stable. I will in time tune it up to perform flips and rolls much like my other mini multirotors.
I am very happy with the overall design and the LED lights really help for orientation. I would consider this a near perfect build, in my opinion :)
Yes, it does look a little messy but it is really difficlult to fit everything in whilst trying to maintain neatness, all components are well secured.
Check out my page for all my other builds, plenty of photos and videos and you may possibly find a solution to some of your own build related problems.
Whilst flying it on the weekend, I really planted it into a tree at high speed. It sounded like a gunshot when it hit and when I retrieved it I couldn't even find a scratch, as if nothing had happened. No bent props, no sign of it having hit the tree. Incredible!!