Quadcopter Post Trial Flights Mods

(To see a list of all my Quadcopter blogs, click here).

As I mentioned in the Edits of my last post on the quadcopter, I had a few problems during the Trial flights. Primarily, I have a bad tendency to overreact if the QC gets in a position I don’t like. That finally resulted in a crash that tore the antenna off and ended the trial flights.

The first thing done was to fix the antenna. The wire tore off right next to the receiver. I ended up opening the receiver, removing the tiny bit of wire left, cleaning up the wire to the antenna and resoldering it to the receiver. It was a fairly delicate operation and I was fully expecting to have to buy a new receiver but the operation was a success. The antenna is now strapped to on of the engine supports, rather than just hanging down as I’ve seen done in some videos.

I recently received a bunch of 3 pin servo female to female jumpers. While I had the receiver out, I replaced all of the single wire jumpers with two of these, leaving just one single wire jumper. When the quad crashed, minor damage was caused to a single pin on the FC (it was bent). Using 3 pin jumpers would distribute the force across more pins reducing such a failure in the future.

I also change the battery mounts. I started off with velcro straps, but I didn’t like them because the battery was sliding a bit no matter how tight I tried to get the straps. I saw someone simply use velcro tape on the battery and the bottom of the QC. That seemed to me to be a good solution and that is what I was using during the trial flights. However, when the QC hit the ground hard, the battery dislodged. Though I didn’t feel that was particularly bad at the time, I decided just velcro tape was not secure enough. I kept the tape and added the straps back. Now there is no lateral movement of the battery and the straps guarantee the battery will not come off.

Another item I had neglected was to get the battery monitor running. Honestly, I omitted this from the initial build because the instructions I had seen required soldering the flight controller board and I really didn’t want to do that right off the bat.

After realizing I could have lost my QC when I was messing with it with basically no antenna, and reading a guy who said his simply flew away never to be seen again, I decided I better get the battery monitor on. This has become a fairly expensive project and I don’t want to loose it to something stupid like loosing power unexpectedly.

Turns out the KK 2.1 has pins for monitoring the battery, and I already knew that the power distribution board I have has pins on it to provide battery status. I simply connected 2 pins of one of the 3 pin jumpers properly and now I have battery status. I followed these instructions:


Finally, I have read various websites indicating that it is a good idea, particularly for beginners, to reduce the maximum control input for ailerons and elevator so the operator can’t be too aggressive. Just what the doctor ordered (in my case)!

I first noted that the max values for ailerons and elevator (using the receiver test on the FC) were -120 thru +120 for both. I then set the transmitter to only transmit 50% of the maximum value to left and right aileron and forward/back elevator. After making that setting change, the FC now reports maximum values of -60 thru +60 for both ailerons and elevator. Hopefully that will allow me to keep the QC under control even when I panic.

The following discusses this setup (step 8):


I’m ready to try again. Unfortunately it has snowed nearly constantly for the past two days and there are no warm days in sight. Another test flight any time soon looks unlikely.


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