Frame: Hobbyking Y650 Scorpion
I will be modifying this frame to be a quad.
Motors: KDA 20-22L x4
ESC: Turnigy Plush 30 x4
Battery: 5000mAh 3S1P 20C
Radio (will upgrade) HERE
I have heard people recommending you start out small but as fare as the most expensive part (the flight controller) goes going with a cheap (just gyro) one would just make it harder to fly.... No ?
Please comment, I need advise.
I know this thread is getting a little old, but I'm just in the process now of working out the best way to use my DT750 motors with the Y650 Scorpion frame.
After much mucking around and evaluating the benefits in the past of using zip-ties (cable ties) to secure the motors on my V2.5 tricopter it looks like the best way is to drill four holes through the motor plates (two each side of the boom) and attach the DT750 base plates that way. Since the stupid base plates have unevenly spaced holes, one side will have the holes further apart and the other closer together. I fed the largest zip-ties that would fit through the DT750 base plate holes. Seems to keep the top and bottom motors in place and you have the added benefit of the zip-ties snapping off in a decent crash to absorb the force of the impact. I've stacked the Tricopter a couple of times now and the zip-ties just break clean without anything on the motor or prop getting bent out of shape.
I've also stuck with the Turnigy 18A Plush ESC's I had been using on the Tricopter as they hardly get warm with the DT750's swinging GWS 1047 slow fly props.
Can I also say that the cheap HK props have always been well out of balance and do not track straight. Not the same issue with any of the GWS props I've purchased in the past. The GWS props look cheap but they track straight and do not require much tape to get the balance right. Barely any vibration from them.
Balance on the motors and props will be even more critical now that this thing will be swinging six props rather than three.
As far as stable controllers go, my MultiWii Paris V4 with Sirus IMU (gyro, accelerometer, mag and pressure sensor) is just as stable as my APM V1 board. The MultiWill suffers from the same oddities with the magnetometer enabled as the APM board. The KK board was nice as well however you had to work harder to get into a stable hover and the onboard video was not as stable.
I also purchased the matching camera gimbal and stuck my old Futaba S3003 servo's on it. Just trying to decide which camera to use with it. Might redesign the motor/camera mount so that vibrations are isolated between them and the main frame. Single board across the underside held on with thick silicone tubing and more zip-ties in a similar way to the Tricopter V2.5 design (rcexplorer.se).
Good luck with the conversion to quad with that frame. + looks like the easier option rather than x.