First Build, First Post, First Questions - Tarot Ironman 650

Greetings - Jeremy from Las Vegas checking in.

I've been coerced into building a quadcopter. I am coming from this from a complete non-existent knowledge base regarding quadcopters, but I am a licensed pilot and know a little about flight dynamics and such - but I learn quickly and I tend to dive into things head first and learn how to swim later - just my personality...

Anyway, I decided not to start small and purchased a Tarot Ironman 650 FPV frame to start my build with.

After approximately 3 days and nights of studying, learning math, power curves, propeller efficiencies and such, I've come up with a list that I ---believe-- to be what I want that can perform the way I want it to:

Tarot Ironman 650 FPV
-- extended 500mm arms for added width
Sunnysky x4110S 340kv motors
DYS BL30A Speed Controllers
1 Lion Power 6S 25C 10400 mAh battery
Pixhawk PX4 + NEO-MN8 Telemetry OSD (will utilize mission planner)
Fatshark 600TVL 100 degree CMOS camera
Boscam TS832 for Video TX

What I haven't picked yet are the propellers - and I won't until the quadcopter is ready to fly as I am preventing myself from either cutting off a finger, being stupid and flying it in my living room, or being too anxious and flying outside before --I-- am ready to fly it.

My questions should be easy, if not, my apologies in advance:

1) All of my math is saying that I will have +/- 40 minutes of flight time (18" propellers) with this configuration - does that sound correct for the parts list above?

2) Did I goof by using a 30A speed controller instead of a 40A? Seeing as how this will primarily be used with programmed missions and very little joystick control I opted for the 30A...was that a mistake?

3) Are there known issues in communication with the Pixhawk and the DYS BL30A that I haven't found yet?

4) I am planning on running 18" propellers, which is why I stretched the arms to 500mm. With the 340kv motors, will I, in the real world, see an increase in efficiency by moving to 20" blades, or just stick with the 18"s?

5) I am also looking for an object avoidance module and have run across the eBumper, but no integration for custom builds. Other than a very expensive LIDAR solution, what other object/crash avoidance modules exist that will effectively communicate with the Pixhawk controller?

Thanks in advance and again, apologies if my n00b questions are annoying.

 

Thanks for the reply!!!

As far as payload, I'm (as of now) thinking of just a gimbal and a gopro. At least that's all that it will be for the beginning. Maybe later I'll think of something else for the quad, but as of now, just that.

I've tried eCalc (the paid version) and I was less than thrilled with it. The selection of items in the battery and controller drop downs didn't contain either my battery or ESC that I wanted, and the custom data entry is suspect. But I've used it to make sure there isn't a red flag in the setup somewhere.

USPS Tracking shows that the frame is being delivered today.

WhoooooT!!