Maiden flight

Today was the big day, the maiden flight of the ascending aid. I choose a small hillsite near Toledo (Magan, Cerro del Aguila) for this first test as the height is only 90m and I had to go back by walking with 15kg of equipment and 4kg of motor/battery.
The wind direction was perfect for this site, north-west with about 5-8 km/h. The test was conducted with the old battery set and the 30" propeller with 10kg thrust.
The ground handling is very easy, the battery pack does not disturb too much. The start procedure is like a normal paraglider. The motor is switched on when airborne to prevent any hazzle with the lines. The motor is also switched of before landing for the same reason.
I flew 2 nearly parallel tracks to compare the sinking speed with and without motor. You can see the details in the track log. The 10kg thrust gives me a ascending rate of about 1m/s. It could not compensate the 1,2 m/s sink rate at this moment, but it would have made the flight much longer if I wished.
Next time I will try the 40" propeller with 15kg thrust. In this configuration, a positve ascending rate should be possible.
Here is the link to the video :

And here the track log:

Arrival of new batteries

Today I received also a new battery pack. The new Turnigy Lipos are 15C rated and weight a little more than the first ones (only 10C). Now I have 6 x 8000mAh 6s batteries. Next test will be conducted to compare the performace of each one. With all batteries I should have a autonomy of about 20min full power. The battery weight is 6kg and the housing motor 2kgs as before. Here a photo of the two battery types:

New BEC

Today I got a new BEC to power the Arduino. The former setup was a smaller BEC rated 6s, which burned down after 5 minutes. Than I installed a 9V battery. with the new beter BEC I do not have to check for the voltage of the 9V battery. as far as there is a 6s 24V LiPo connected, the Arduino has power. Here is the photo of the old and new BEC (old, small one is already junk):

Ground test with video

In this viedo you can the the assembly of the eHayabusa to the standard harness Swing Connect Reverse. The test was conducted with the 30" propeller. Than I tried the 40", which gives >15kg of thrust. But in this configuration the heating of the wires is to much, after 60 seconds I stopped the test. I will install a new software version for the 40" propeller to limit time of full throttle to prevent any overheating.

https://www.youtube.com/watch?v=C8QBHXXR0wA

Continous run test for 6:00 minutes

One of the most important test was conducted today, the continous run test. I started full throttle with nearly full batteries to check the power consumption of the motor and the heat dissipation.

The result is very convincing: at full throttle with the 30" propeller I operated the motor for exactly 6:00 minutes. The cells were depleted afterwads to 22.7V that means 3.78V (LiPo 6S).

That is a fairly good value and there would be still some reseserve power. As the cells had seen some short tests before, I estimate the total operational time of about 7:30 minutes.

That is also more than initially expected.

The ESC has a shut-off controll for low voltage to protect the battery, so there is no problem of damaging it with to low voltage depletion.

Another important point is the temperature disipation. I checked with an infrared thermometer and the motor housing is getting to 78ºC at the end of the test. The power cables are also getting warm, around 40ºC. The battery itself only changed to 35º, also the electronics is not getting any warmer.

Static thrust on ground

I measured the static thrust on ground with a normal digital scale. The measured result was 10.1kg with the 30" propeller and unbelievable 14.9kg with the 40" propeller.

From the photo you can see that the axis has a inclination of about 25º. That means the real thrust in propeller direction is about 10% higher: 11kg for the 30" and 16,5kg for the 40".

That is far more than I expected for the 40".

Measurement setup with a sand bag to avoid the movement of the housing on the scale:

Propeller

The standard propeller for this electro  motor is a 30x8 inch plastic propeller. That is a diameter of 80cm. As the effectiveness of a motor depends on the propeller diameter, a larger one would be more apropriate.
For this reason I converted a 30 inch propeller with carbonfiber tubes to a 40 inch propeller, 101cm.
The thrust of the 30" should be about 120 N, increased with the 40" to 150N, nearly 15kg.
The propeller is well balanced and does not produce vibrations at higher RPMs.
Here is the comparative photo: