Monday, June 11, 2012

Turnigy Talon V2 Build: Part 3 - First Flights!

Final Hardware Setup
Late last week the APC 10 x 4.7 SF pusher props showed up at the local hobby store, so I was able to finish up the quadcopter and try some first flights. I used a pair of velcro cable tie straps to hold the battery in place.

I marked the "forward" legs of the quad using white electrical tape. Hopefully this will give enough visual definition- if not I'll have to find some colored props.

ESC's zip-tied in place
Velco Cable ties on the bottom for the battery

Hobbyking Multi-Rotor control Board v2.1 Firmware Update
I was able to take off, but flight was a bit sketchy, and the platform did not seem very stable at all. I've read quite a bit on RCgroups about kapteinkuk's updated kk board firmware and decided to make the upgrade.

The instructions that hobbyking includes in their instruction manual isn't the easiest in the world to follow. Luckily Flitetest has a great video to walk you through the process.

Following their instructions, I was easily able to download and install the driver for the Hobbyking KK board programmer.  The next step is to download and install the actual software for updating the board's firmware. This is where I ran into a bit of trouble. I tried downloading it several times, and even following Flitetest's instructions to the letter, I could not get the KKmulticopter flash tool software to run. After digging through the flash tool software website's help, I found an explanation about the Java version required to run the software. It turns out if you have a 64 bit flavor of windows (which most is these days), you might need to have both 32 bit AND 64 bit Java installed. By default the 32 bit is installed, but it won't run the flash tool if you have a 64 bit system. So, I downloaded and installed Java 64, and sure enough it worked. After that upgrading the firmware was a snap.

I chose to install Kapteinkuk's 4.7 x-copter software. This also required rewiring each of the motors because the rotation direction changed for each prop. A quick tip I learned is to leave the ESC leads a bit long to allow easy reversal of motor direction.

Before doing anything else, I ran out and tried to fly... I found out immediately that the yaw gyro was reversed- as soon as the landing skids left the ground the entire aircraft started spinning like a top. No good there. So I located the instructions online on gyro reversal, fixed the yaw axis, and also followed the instructions to recalibrate each ESC. After all of that, the update seems to have really helped.

Another note is that zero on the pots seems to be full CCW not CW as discussed on some locations online. Even without spending much time yet tweaking the P and I terms for pitch and roll, and the P term for yaw it is already much, much more stable than the stock firmware and enormously better than my old tricopter.

I'll be posting the terms once I figure out what works best for my setup.

I've copied some basic setup information from KapteinKuk's and other's posts on RCgroup's for easy reference:

Roll pot now controls P-term gain on roll/pitch axis.
Pitch pot now controls I-term gain on roll/pitch axis.
Yaw pot controls P-term on yaw axis as before. Yaw axis I-term is fixed at 0.2

X-mode setup:
Motor 1: front left, CW
Motor 2: back left, CCW
Motor 3: Front right, CCW
Motor 4: Back right, CW

Suggested initial setup:

P pot at 50%

I pot at 0% (it can be left at 0% since it does not have a secondary function.

Yaw P pot at 50%

Trim it level.

Adjust P (roll/pitch) to your liking.

Add I until it flies straight forward without pitching up.

;---- Gyro direction reversing ----
;---- 1: Set roll gain pot to zero.
;---- 2: Turn on flight controller.
;---- 3: LED flashes 3 times.
;---- 4: Move the stick for the gyro you want to reverse.
;---- 5: LED will blink continually.
;---- 6: Turn off flight controller.
;---- 7: If there is more gyros to be reversed, goto step 2, else set roll gain pot back.
If you move the throttle in the step 4 above, you will reverse the pot direction.

;---- ESC Throttle range calibration. This outputs collective input to all motor outputs ---
;---- This mode is entered by turning yaw gain pot to zero and turning on the flight controller. --- 

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