Andreas's Posts (8)

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APM enhances Father's day

3689530285?profile=originalIn FBW mode, the APM turns almost any plane into a perfect trainer. My two older daughters (9 and 7) were able to confidently circle over the Berkeley marina. Despite the 10-15 knot winds the Bixler2 behaved very docile and controllable. I had them completely ignore throttle and only focus only on the aileron.

I was amazed on how stress-free the flights turned out. After a few minutes of practice I felt confident enough to stop watching the plane and take some pictures of the young pilots.

Besides getting cold from the wind they enjoyed it and want to come back out to the field with me. I'm thinking to let them practice a few times in FBW (to get used of the correction when the plane flies against you) and eventually graduate them to stabilized mode.

3689530107?profile=originalHard to spot the plane, but it is there ;)


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Drone shot down by police

While filming the protests at Taksim Square, Istanbul Turkey, a DJI Phantom is brought down by police. I'm surprised that he managed to keep the footage. Many people arrested at the protests report having their memory card wiped.


Yes I made that headline as sensationalistic as possible ;)

Polisin vurarak düsürdügü helipoterden görüntüler! / Footage from Police shot helicopter! [HD] from Jenk K on Vimeo.

Polis kameralı helikoptere ateş etti / Police shot RC copter @ Taksim Gezi Park from Jenk K on Vimeo.

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RCTimer Brushless Gimbal and Controller

It's amazing how quickly BLGs went from a novelty and costing thousands (zenmuse) to something you can get for $172 shipped!


I received my RCTimer Brushless Gimbal (BLG) and controller (Martinez v1) yesterday and of course had to try it immediately. Mark came over and helped with the build and documentation. The kit does not come with any instructions, so the RCGroups thread is the best source for build info.

Overall the quality of the RCTimer kit is not bad. There was one missing screw and a few things we had to alter to make it fit (see the build log link below for details). But the material is easy to work with. The default firmware and settings on the board seem to be pretty decent for a start. We initially had the IMU orientation and motor connections different, the result of that was shaking in the pitch axis. Once positioned and connected as shown above, it started to work fine without any parameter changes.

Build log with many detailed pictures:

Video showing connections, start-up sequence and motion test:

Time lapse build video:

Next up: Connect to the GUI (no luck so far), connect the RC, fly...

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Drone vs. Drone

See what happens if two APM powered quads get too close to each other.

The innocent ArcticCoper was in loiter, the TBS Discovery was in stabilized trying to get close up. Slow motion footage shows how one motor of the AcrticCopter completely stops after hitting the TBS Discovery quad. The damaged propeller then drags one arm down of the TBS Discovery, you can even see the propeller bend.

Both quads survived, only damage was a clipped prop on the ArctiCopter.


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FPV Video with failsafe demonstration


First off, nothing bad happened. In a recent FPV flight at Berkeley Marina, I inadvertently triggered my remote’s failsafe mechanism four times. You can observe the failsafe kick in at 1:04, 1.54, 2:34 and 3:02. Each time the plane banks sharply towards the launch position and the throttle increases aggressively.




The remote is a Turnigy 9XR with the FrSky transmitter module and receiver. On the transmitter I use the range enhancing FrSky patch antenna. The flight controller is an APM 1.5 with the latest ArduPlane 2.70. The failsafe mode is set to 50% throttle and Return to Launch (RLT). The plane is a Zephyr II with a NTM 35-30 1800KV motor and a 3300 mAh 4S battery.




As you can see from the map, some of the FS points are actually not very far from the remote at all. The mistake I made was that I pointed the patch antenna to the ground instead of the plane. But this mistake is hard to “see” when wearing FPV goggles.


Key takeaways:

  1. It’s important to own a remote with failsafe capability.
  2. If you own a remote with FS, it’s equally importance to setup the appropriate failsafe operation.
  3. All this could take a turn for the worse if GPS was not initialized properly, never take off before a GPS fix is established. Also a good idea to switch to the mode to see that it acts correctly after takeoff.
  4. Even a good remote can have limited range if the situation/arrangement is not ideal.


Fly safe!

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The $10 Hexacopter Frame


Frame Material:

3/4" x 3x4" fir stick for the arms  (8 feet is enough)

Plywood for the center plate (~ 6"x18*)

Machine screws & bolts

6 Wiffle balls

Lots of cable binders


26" Motor to motor (can fit 10", 11" and 12" props)

6" Hexagon as the center plate (3 times)

Finished weight is about 5.5 lbs. (With my quad and the same build method and motors I was able to lift 8 lbs payload using 4S).

Build time for entire copter: 4 hours



9x with FrSky module and receiver

2x 4000mAh 3S, one powering 3 ESCs each (in a triangle, I'm hoping it could fly with only 3 motors in emergency)

6x 40A Turnigy Plush

6x NTM 35 1100 KV

10"x4.5" Props

Center plate pattern, drawn with Visio:


Pattern is super-glued on plywood and used to cut plates and glue arms in correct position.

Arms with center plate sandwich:


Power distribution level, will be covered with a third center plate:


Finished Hexacopter, maiden flight in the basement was successful. Will need some PID tuning. The noise is quite something ;)



Print hexagon pattern with arm orientation
Glue pattern on plywood
Use miter-saw to cut hexagons
Cut arms, one 28.5", four 13.5"
Super glue arms on one plywood plate matching arm pattern
Super glue second hexagon plate
Drill holes for machine screw and fasten
Drill holes for motors, 2 holes for each motor make sure distance to center is equal
Build power distribution with spider method (strip cables in middle, pull one cable through the other and solder. This yield a 4-end distribution, perfect for the hexa, 3 for ESCs and one for the battery, build 2 each)
Cover power distribution layer with another center plate
Attach motors, ESCs
Insert APM, receiver and batteries

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