"Battery,
battery wires and/or current/voltage sensor,
power distribution board and maybe another voltage regulator board if you need 5v for cameras and don't want to run them off of the pixhawk's…"

"The Y6 uses an autopilot system called Pixhawk, which uses Arducopter firmware.  Pixhawk is very similar to the ArduPilotMega, or APM flight controller/autopilot.  So, any programming or testing you need to do will be covered in instructions for…"

"I was pretty sure everything after a DX7i allowed you to program the outputs from the transmitter's own menus, right?

If you want to do it in the Pixhawk itself, then look at the RC Map options:
http://ardupilot.org/copter/docs/common-rcmap.html"

"The center of gravity should end up at the center of the three arms.  If you draw a straight line along the center of each arm, you can find the intersection of those three lines.  I took a silver paint pen and put a tiny dot at that point on the…"

"I do not.  I believe compass calibration shouldn't have to be changed unless perhaps if you travel to a different launch location that is very far away from where you first did it.  I have calibrated my machine in East Texas and taken it to New…"

"Thanks.  Good info.

I got 6 modes working, but I was after the elusive 7th channel."

"Am I just remembering this incorrectly?  I thought home was reset to where the machine was last armed, not where it was powered up?  "

"Does anyone have a link to a good write-up of what's involved in using the NEO-M8N?  I'm not finding much concrete beyond specs on it."

"Another way to do something like this would be to use gas engines. There is a racing quad that uses one gas engine and four variable pitch props. That is probably something that would scale up nicely. The problem with scaling up a normal quad or x8…"

"Late hit here, but I'm interested in where you put your ground shield, and how big you made it.  Any other posts or info you would care to share on this?  Thanks."

"Good advice all around.  Don't worry about attaching a gimbal or camera until you have the thing pretty well figured out, or unless your wallet can accomodate a desire to get lots of great crash footage.

Learn about battery voltages (i.e. how low a…"

"I think the rule of thumb is not to use a battery below 80% of its capacity if you want it to last a long time.  Leaving 20% of 4000mAh would have you enter a value of 800mAh.  You might want to leave more to make sure it can complete its RTL, or…"

"The improvements made to this are now part of #1406.  Any testers out there.  

https://github.com/diydrones/ardupilot/pull/1406"