EDIT Jan 2020: Hello RotorBuilds!
I'll be honest, forgot I had made this page almost 3.5yrs ago now haha! But, as many of you know the T18 frame and Octo's in general are not common and finding any info on them is wonderful. So I am going to try to update a little bit on it! It flies wonderfully and I flew a lot while I was in college, especially for promotional events, nothing attracts people like a flying lawnmower. The FAA rules have changed so much and I have yet to do the Part 107. I am nearly to my PPL so I am just trying to figure what will be the best path. ANYWAYS, enough about my life.

What people care most about are the battery mounting plates. They are completely custom and made by me for this frame. I don't have the STLs out in the public, but do sell the mounts or can sell GCode for you to print your own. I have multiple versions of the battery plates. A clean version that doesn't have the mounting plates for the legs, and one with. (I will post some photos of the mounts in the gallery) I also take commission to edit the file if you wanted a different landing assembly to attach to them. You can direct message me here, leave a comment or find me on Reddit at r/Expensive-Hobbyist and dm me. Reddit may be the easiest way.

Lessons learned on this copter.
1) Buy the best batteries you can afford. These batteries do NOT have a high enough C rating to keep up with how quickly this beast drains them. I have puffed all 6 of my original batteries and they are the reason I have spent the most time on the ground.
2) Don't autotine your PIDs: I have seen plenty of people struggle with this. I haven't seen a controller that autotunes large octos perfectly yet, and typically they introduce more issues than they fix. There are an immense amount of Youtube tutorials on how to manually calibrate your PIDs. It is a lot more work and time, but much more worth it.
3) Keep a good wiring diagram and be as NEAT as possible when wiring. If you ever have to do maintenance, not knowing where your wires are going is a nightmare. Label all your wires and to which arm they go.
4) Buy the best FC you can afford. The OG pixhawk is fine, but is not nearly robust enough for my liking. I want to update to a full DJI kit with triple GPS, but I don't have that kind of money.
5) TAKE. THINGS. SLOW. Realisitcally this copter is a 12-15lbs flying death machine that will cost you anywhere from $2k to $5k. Be smart. Don't yank it off the ground in the first day. Figure out its ticks and its problem areas. With its weight, it does not fly like a sub 2 pound quad. It'll twist and turn if your PIDs are off. Be a skilled pilot and practice on other frames first. I realize this was my first copter, but I do NOT recommend it. It was a terrifying thing to learn on.

There was a lot of other equipment that was added to the copter after the main flight components. So if there are any other questions please feel free to reach out. Good luck and happy flying!

Original post below:

So I just got air worthy two weeks ago and have flown about four times. Its currently grounded due to not having a charger with the ability to charge my 10,000mAh batteries.

But a little background, Ive never built a drone of any type, or even something RC. I do have a small RTF racing drone that I taught myself to fly on first before I attempted this. And I spent the better part of two years doing a lot or research and saving my money.
When I started out with my research, so many people are quick to shoot people down who want to start with an octo, with good reason! But I don't like being told what I can't do, so here we are!

In the future I am working with a friend who is in college for Cinematography and we are making a company to do aerial footage. (Yes I am aware of the 333 Exception and being a pilot and such) Our primary camera/gimbal will be a Ronin M w/ a Lumix GH4 and we may get an opportunity in late summer to fly with a Red Epic Scarlet! But I have a lot of testing before we get there!
Comments, suggestions, and questions are always welcome. Thanks for looking!

Frame: Tarot T18
Flight Controller: 3DR Pixhawk w/ UBlox GPS
Motors: Tarot 5008 340kv
ESC's: Hobbywing 40a
Props: Quanum 18x5.5 CF
Batteries: 4x Multistar 10.0A 6s Lipo
-2x Zippy Flightmax 5.0A 6s Lipo
Retracts: ARRIS x5
Tx: Taranis+

Stats:
Max Flt Time: TBD (~20min no payload, ecalc)
Max AUW: TBD (~6783g, ecalc)
Max Payload: TBD (~11228g, ecalc)