A couple of months ago, I took out an Elev-8 quadcopter that I built and modified for a fun flight outside the front of my house. For those of you who are unfamiliar with the Elev-8, it was a kit that I bought from Parallax, a company in California that sells kits/parts for people who want to learn about robotics. Anyway, I modified the original quadcopter by replacing it's basic flight controller with an APM2 F.C. with GPS and telemetry. The resulting aircraft allowed me to select any of three flight modes at a time (I can choose from a dozen or so and put any three on the aircraft). It had so many features that I won't go into, as many of you are familiar with the APM which has been around for along time. Here is what it looked like: I loved to fly this thing! It was stable and fun to fly. Then, one day, a couple of months ago, I took it outside for a short flight. It flew flawlessly as I expected. I decided to give it full throttle to see how well it would accelerate vertically - just as it rose about 20 feet, I heard a loud crack and it pitched over and crashed in the street. I thought there was a mechanical failure, but saw nothing come off the aircraft as it fell. It was totaled. I was going to trash it, but decided to gather it up to see what I could salvage. In the meantime, my wife and I decided to sell our house and move to Colorado. I brought the crashed remains with me. After getting settled in our new house, I set up a work area in the basement and unpacked the pieces: Looking around, I found lots of spare parts that I had ordered at various times to repair this and two other Elev-8's I had. After conducting an inventory, I decided that I had enough spare parts to rebuild this aircraft But before I begin, I had to try to salvage some things - the wires going through the booms from the motors to the ESC's which were mounted on the center chassis, etc. I also decided to remove and replace the ESC's and while doing so I made a discovery. The ESC for the #3 motor had a bad solder connection - the bullet connector came right off the wire. The #3 motor is the left front and it suffered the most damage - it came down on that boom and cartwheeled so that the left rear boom/motor took most of the remaining shock and damage. The other two booms and motors seemed okay but on closer examination, one of the remaining booms was slightly dented. Here is the suspect - note the missing bullet connector on the red (power) lead: These were 40 Amp ESCs and I decided to replace them with the stock 30 amp devices that came with the kit. But after awhile I began to wonder about changing motors. I have four brand new KA outrunner 1050Kv motors, but I also have a bunch of Tarot 4006/620KV motors. Hmm, maybe I can use these... There is a dirth of information on the Tarot motors and lots of bad reviews. but hey, I've got some and might as well use them. so, based on info I gleamed from other forums, here's what I'm expecting. After searching through my bag o parts I think I have pretty much everything I need to rebuild the aircraft. I did decide to order a new set of ESC's - will wait until they arrive. Here are the parts laid out: I'm hoping that the all up weight of the final aircraft to be around 5 - 51/2 pounds. At 50% thrust, I'm expecting to get around 700 gms thrust per motor using 13x5.5 props => 6lb 2.75 ou. I'm expecting to draw 3 A per motor, so with a 5000mah lipo I could get over 20 minutes flight endurance. This will be a running thread - I hope to add to it as I get into the build and document my progress. At the end, I weigh the aircraft and conduct some endurance tests to see how far off I am with my expectations. Feel free to comment - if you think I'm off on my numbers then please, let me know!