The GFS-UAV model N-01A
Flights tests Logbook
created on March 31, 2006 - JLN Labs - April 7, 2006
Toutes les informations et schémas sont publiés gratuitement ( opensource ) et sont destinés à un usage personnel et non commercial
All informations and diagrams are published freely (opensource) and are intended for a private use and a non commercial use.

• March 30, 2006 : 1st preliminary tests results in laboratory.

  

  Due to windy and stormy weather conditions, outdoor tests can't be performed. So, I have conducted some lab tests in the main lab. To avoid that the craft lift-offs suddenly in the lab and crashes on the wall, I have used a bigger and heavier Lipo battery than the normal model.

  The purpose of these tests are to :

  1. Check the effect of the anti-torque system (the 12 moving rudders controled by the piezo gyro).

  2. Check the efficiency of the yaw control while the craft hovers above the ground at very low altitude (in the ground effect range).

  3. Measure the upward trust on a balance.

  Tests results :

  1. The anti-torque system is really efficient, the gyro gain is well tuned and there is no parasitic torque induced by the rotation of the propeller.

  2. While the N-01A hovers at low level above the ground, it can be easily controlled on its yaw axis. I have noticed that the model has tendency to incline itself forward, so, I shall need soon to check the CG and the main motor axis.

  3. To measure the trust, I have placed the N-O1A on a high precision balance.
     At full power the measured trust produced by the Rex220/1300 and the 9x4.7 propeller was only 295 g...

  

  Conclusion :

  These preliminary tests have demonstrated that the anti-torque system is really efficient and the control of the model on its yaw axis works well.

  The brushless motor Rex 220/1300 is not able to provide a sufficient upward trust to provide a good lift-off. So I have decided to replace this motor by a higher power engine. I have used an AC 28/7-30 D brushless motor from MP JET.

  

  Number of cells	6-9 or 2-3x LiPol
  RPM per Volt	1100
  Maximum recommend speed (min-1)	12000
  Maximum speed (min-1)	15000
  Maximum efficiency (%)	approx. 79
  Current of maximum efficiency (A)	to 15
  Short time currrent (A)	20
  Internal resistance Ri ; (mW - miliohm)	81
  Dimensions - diameter/length (mm)	35,5/33
  Shaft diameter (mm)	3
  Number of turns	30
  Weight of drive unit (g)	56
  Recommend propeller range	APC 7/3 - 9/6 (10/4,7)

  
  The brushless motor is connected to a speed controler JETI Advance 30-3P

  
  Different types of propellers have been tested in the lab : Above a Graupner CAM Folding prop 9x5

  March 31, 2006 : Several lift-off and hovering have been done successfully with the new motor in the lab.

  
  Today, the best propeller tested is an APC Electric 10 x 7 E from Landing Products.

The tendency to incline itself forward observed during the previous test has been corrected by adding 18 g of lead to the opposite side. With such a setup the GFS-UAV has done successfully several short lift-off and hovering in the lab, but I need more space to fly at higher altitude...

Click on the picture to see the video (1.1 Mb)

Today, I recommend you to use at least a 150 Watts brushless motor with your GFS-UAV N-01A

April 5, 2006 : Improved trust and better stablity with the streamlined body around the propeller

Today, I have added a streamlined body 280 mm diameter and 60 mm height and placed at 45 mm above the hull. Wooww, the efficiency is greatly improved and I have been surprised by the sudden lift-off of the N-01A and its remarquable stability. The strealined body is made with a 3 mm thick depron foam and fixed with 8 carbon rods (2 mm diam) on the hull.

I recommend strongly to add this body on the GFS-UAV.

April 7, 2006 : Successful OUTDOOR tests flights !!!

Click on the picture to see the photos and a video of the outdoor flights.

More tests results are coming soon, stay tuned...

For more informations, please contact Jean-Louis Naudin : JNaudin509@aol.com

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