Over two years have passed since I started this thread... In 2012 I flew a glider mostly, so I didn't played with multirotors much... then In the autumn 2012 I've build all-aluminum H-Quad with KK (v1) board (basically all the electronics from the tricopter above)...
http://forum.flitetest.com/showthread.php?2357-H-Quad-Scratch-Build&p=33892#post33892
It worked... a bit, but I crashed it before I even learned how to fly it well and it was hard to repair...
In the meantime I took an Georgia Institute of Technology internet course on control of mobile robots and learned alot about all the things needed to understand how the flight controllers work (especially about PID regulator and all the math).
Then I finally decided to buy ArduPilot Mega 2.5 with uBlox GPS. I've installed it on my old tricopter frame (with minor modifications) - and wow what a stability (compared to the old HK KK boards). I finally learned how to fly multirotors.
My scratch built tricopter with APM 2.5 (David's frame design mostly):
Plush 40A ESCs, HK Metal Gear Analog 9g Servo, DT750s and 11x4,7 or 12x4,5 Props. 2x1300mAh in parallel or 1x2200mAh 3S packs. Around 8-10 minutes of flight (with camera on board).
Some video footage:
It flew like a charm even without PID tunning at all.
Later I added an UHF telemetry module.
Finally last October I decided to dismantle it.
I designed a better frame and got it CNC cut from 1,5 mm black glass laminate.
I did a minor mistakes in this design but refined the flaws and now I'm pretty satisfied with the final product (I already got even more refined version in the CAD files).
As you can see it still has DT750's from my first tricopter, same ESCs etc.
It's also equipped with a BL gimbal with martinez controller. I just ordered bigger batteries because it's heavier (still hovers at 50% throttle though).
I already flitetested it - some minor tuning is required (small oscillations).
It's also very easy to convert it into Y6 copter (which I might do this spring - finally getting rid of DT750s and using SimonK firmware ESCs).
My other plans include a hexacopter - either based on the 550 V2 HK frame (or similar DJI clone with integrated PCB) or custom build frame (I have some crazy ideas for this frame).
Also I would like to build some smaller quad - like TBS Discovery Pro (which unfortunatelly is way too pricy for me) for FPV (but first I've got to complete my FPV equipment - at the moment I miss only a camera - I have all other necessary parts including MinimOSD for APM).
