February 12, 2015

Last parts for the Trifecta just arrived

It's not because it took a long time to ship them but more because it took a long time for me to decide to finally order them. The two last pieces for the Trifecta just came in the mail. First off is the video transmitter. There isn't much of a choice here considering limited space on the frame. I've had great experiences with the Skyzone TS5823 before and I'm going to use it again on this frame. I see no reason to use the expensive and clumsy Fatshark and ImmersionRC transmitter when not flying at long distances.

The second part is more of a test. It's the simple antenna mount from HobbyKing, I think it will come to good use since there's otherwise not many opportunities to attach the antennas on the frame. I'm stuck with long antennas due to the choice of a Futaba telemetry receiver, otherwise I would have picked a parkflyer receiver with a short antenna.

Skyzone TS5823 and antenna mount

February 7, 2015

Easy to use LEDs for 3S LiPo

I read a post on LEDs a while back and someone advised the OP to buy a set of QAV250 LEDs. Those LEDs are purpose built to fit the power distribution board of the QAV250 but they can be used for so much more. Being small, rigid and designed for 3-4S usage they are perfect for little add-ons to any build. I just got a pack of them from banggood yesterday and it's looking great. They are more powerful than I thought and for the price they're great. They also comes in packs of 5 and 10, even a little bit cheaper.

I'm feel some regrets that I didn't include this in the build plan for the Trifecta. Maybe I'll go back and make a place for them anyway...

February 6, 2015

Don't fly with worn out batteries

I have a worn out battery that I use on the bench for testing the parts of the machines that shouldn't consume that much. I've used the battery for this for quite some time and apparently I've forgotten how bad it really is.

Because today I tested out the settings of the CC3D in the Ghost 250 quad. And it didn't turn out that well. I noticed early that one motor was lagging and that full throttle did not punch nearly as much as it should. And after a few seconds the quad was having problems flying at all. And then one motor died.

I didn't have telemetry logging enabled. And stupidly enough I hadn't set up the voltage alarm neither. The only thing I know afterwards is that the smallest voltage reported was 6.5V. For a 3-cell. Well, I 'm surprised it flew that long. Check out the end of this video, and you'll see what happens when the battery runs out faster than you expected.


February 4, 2015

Unisense-E

I got the telemetry sensor for the Trifecta the other day. This time I wanted to try out the Unisense-E instead of the usual e-fuelgauge that I have gotten used to. The main advantage of the Unisense-E is that it contains a vario. The vario is a air pressure sensor that reports relative altitude and rate of ascent/descent. Additionally, the sensor measures motor RPM using a connector to one of the motor leads.

Unisense-E
Sensor with CC3D and Receiver for comparison


The device is very small considering the three built-in capabilities and the additional programming connector. However, it is offered with a few connector options, which makes it clumsier. Optionally you can get it with a hefty 4mm² wire which is only necessary for really high current installations.

I'm going to pull some 25A through it so I had to take it apart to replace the wires with lighter ones that are easier to fit inside a small air frame. Here's what's under the hood.

Unisense-E
Unisense-E the shunt resister sensor and signal connector


Unisense-E
Unisense-E processor and configuration port connector