So, I installed the RC911 firmware on my quad yesterday, thought y 'all might want to know how i...

[G+_Michael Heinz]

So, I installed the RC911 firmware on my quad yesterday, thought y'all might want to know how it went. 

 

The following is a straight cut-and-paste from my log book for the flights, some of it might not make sense without reading the previous bits, but you should be able to pick it up.

 

1. During last set of flights I twice experienced a momentary power failure, once leading to a pancake in the woods. No parts damaged, though when I ran some static tests I noticed that motors 2 and 4 tended to slowly stop at low throttle levels. Afterwards, I discovered the power harness had nearly melted apart (probably from going to 100% throttle when trying to prevent the pancake) and the positive lead was no longer well attached. Replaced harness and adjusted wiring to better protect the wires from getting tangled in branches, vibrated loose, or getting clipped by the props. Since I had to remove the controller to get to the power wiring I also installed different KK2.1.5 controller to see if it would affect the "yips" (oscillation) the quad has been having since moving to a 260 frame.

 

2. Also installed RC911 firmware instead of 1.19S1 Pro, which pretty much made the results of rewiring and the new controller too hard to interpret. Default values are all very different, I suspect I need to completely retune the PI settings. The new "Initial Setup" menu is nice, makes it hard to forget a step. "Lost Model" alarm also occurs much sooner - if the quad is armed with throttle at 0 for more than 20 seconds, the alarm goes off. On-screen instructions for ESC calibration are confusing - it took 3-4 tries to calibrate 0-throttle correctly.

 

    2a. Made the minimum # of changes to the firmware settings that I had to to fly, left all tunable parameters (PI, stick scaling, etc..) at their default values.

 

3. First flights were also under gusting conditions, which further weakened any conclusions about the yips.

 

4. Programmed the Taranis to use the voice of Tiny-Tina when I go into Acro mode so I have an audible warning if I hit the button by accident.

 

That said…

 

A. HOLY SMOKES! The “SL Mix” and “Acro” modes were scary. Need to practice more with them.

 

    A1. In SL mode I tended to climb when reversing direction (as before). (Why does this happen?) In Mix and Acro, I tended to descend.

 

    A2. Moving the stick more than a small amount in any direction in Mix mode can have exaggerated effects. Banking in turns almost always leads to the quad being heavily tipped forward and banked a lot more than I intended. Still not sure if I’m not pushing the stick in the direction I think I am or something else. 

 

    A3. Recovering from problems by centering the elevator and ailerons (in mix mode) or switching back to SL mode (acro mode) was quite fast. Successfully dodged all unplanned interactions with local trees, although once I had to hit full throttle and climb to make sure I avoided hitting the tree line on the opposite edge of the flying field.

 

B. I left the firmware at initial PI settings and I still saw lots of shaking but it tended to start then damp down instead of building until broke the cycle. It’s possible properly tuning the PI settings will further improve things.

 

C. The swallows are getting angrier – I had an entire flock come to try and chase the quad copter away from the flying field. (I got one picture of them buzzing the quad enmass but it was getting dark so it's just a bunch of blurry dark pixels - you can't tell if they're birds or bugs stuck to the lens.)

 

D. Flight times were short, even with newest batteries. Hard to decide if it’s due to more aggressive flying or weather conditions or both. Batteries are rated for a 2C charge rate but it appeared they didn't accept as much energy when charging at 2C than they typically do at 1C.

 

E. If I do have a bad/slightly out of true motor, how do I identify it?

 

7 flights from the last crash.

[G+_Michael Heinz]

Agreed; and I'm not sure exactly when it occurred. The melt occurred right at the end of the JST connector, so it's possible that the wire had gotten yanked hard enough to expose a bit of wire, creating an intermittent short which is what caused both the melting and the momentary losses of power I experienced. 

 

The replacement harness is an octopus arrangement but also a heavier gauge so hopefully this won't repeat.

[G+_Michael Heinz]

Wayne, this is the main power harness and it's how the kit ships. You can see it in the pictures here: http://www.hobbyking.com/hobbyking/store/__62706__HobbyKing_Spec_FPV250_V2_Quad_Copter_ARF_Combo_Kit_Mini_Sized_FPV_Multi_Rotor_ARF_USA_US_Ware.html

 

The batteries use a male connector, the quad's power harness uses a female one.

[G+_Michael Heinz]

Battery in question: https://www.hobbyking.com/hobbyking/store/__58581__Turnigy_1000mAh_3S_20C_Lipo_Pack_AR_Warehouse_.html

[G+_Michael Heinz]

New harness: http://www.hobbyking.com/hobbyking/store/__25477__JST_to_4_X_2mm_Bullet_Multistar_ESC_Quadcopter_Power_Breakout_Cable.html