Get Adobe Flash player
Banner
Error
  • Delete failed: 'joomsef.cache'
  • Delete failed: 'cache__0482d012660b2620d029b0faa9b8f06b'
  • Delete failed: 'cache__074ec921d137ae5c864de73abd89406c'
  • Delete failed: 'cache__0c7d3cd64e9a8145ffa536554d7f3606'
  • Delete failed: 'cache__0d09950006d2d4d9d7cbf9d307dbee1f'
  • Delete failed: 'cache__0deb5218b5a94ff4643fe8a44ce0af52'
  • Delete failed: 'cache__15206fda057623f6ac7232383c82fa59'
  • Delete failed: 'cache__1965e8ff15caec7d575876a0838f4e42'
  • Delete failed: 'cache__1b1fde0e2ca55b22209751e7d3a8d33c'
  • Delete failed: 'cache__1d83a35e54bfafa4795d2b4d62abcc2f'
  • Delete failed: 'cache__220c94a0180046235e76b4eb6a0043bf'
  • Delete failed: 'cache__229c9a0e6b2ce7108ae64d8c10d885d3'
  • Delete failed: 'cache__2379b1c3230a3e844191002be5785f34'
  • Delete failed: 'cache__25aa8d4e0962d64ff54b0b944835ceba'
  • Delete failed: 'cache__2df841c66e38f9e148f51b472d4f70df'
  • Delete failed: 'cache__2e7dca24b073c2d1e9542e933ef020eb'
  • Delete failed: 'cache__2f43826e644bd53b88d58d9581857392'
  • Delete failed: 'cache__31be10e778f1a76e4ac179be5a67925d'
  • Delete failed: 'cache__3bc462edd477cc130de98cec877163ae'
  • Delete failed: 'cache__3f8f99b2905d72bd9e9ddbb68905275f'
  • Delete failed: 'cache__405f08078954ec6dff65d93d5bc6be16'
  • Delete failed: 'cache__4080216f498116668921fdf5c2b2f04c'
  • Delete failed: 'cache__409fbd4f9bd684958d59fb315fcf621c'
  • Delete failed: 'cache__42379a05b2f55c2fed97acdcce09cc91'
  • Delete failed: 'cache__4516a0fb9c3683e5968a5e6bc9ca6407'
  • Delete failed: 'cache__49c80b1df49a4817d5f506cf18cc8024'
  • Delete failed: 'cache__4ce13c65ca3185402f75b67f0d0fd104'
  • Delete failed: 'cache__4ef11a48e80d4165facef79617d853d7'
  • Delete failed: 'cache__4f45e9df8df65a3c05bc4c214b306760'
  • Delete failed: 'cache__51d61599e786ba3812d16f85a205bb5d'
  • Delete failed: 'cache__590e78641472e960d63f40b62c0076b7'
  • Delete failed: 'cache__5997b3c37b73750fca1a1c0be2798c34'
  • Delete failed: 'cache__59e300644b6146b4d249fd20499badde'
  • Delete failed: 'cache__5a7fea53c586b6ea81ad78d9d90cd4fe'
  • Delete failed: 'cache__5b6de05d88255a996c4667ed6ce23fac'
  • Delete failed: 'cache__5cda0b7faeee11fab1c9f0b65c5b490d'
  • Delete failed: 'cache__5ed516b504c8b1f3a8b128a5ddd99538'
  • Delete failed: 'cache__6338aca1f4c0b048cbb19a0bf0fd1e23'
  • Delete failed: 'cache__6484c800a9dfdd098b6b84717ee0f031'
  • Delete failed: 'cache__6a84ad70d16687dc05b879775a2cfa5a'
  • Delete failed: 'cache__6bc5317055e2eb09470d5752784e51d5'
  • Delete failed: 'cache__6c6d1f45c33b7958bb5404ec6a9b9b87'
  • Delete failed: 'cache__7212917447b342e32644519e5ffabe37'
  • Delete failed: 'cache__738e543a3bc0f2a04b51dba2a82c3ef0'
  • Delete failed: 'cache__75b9883e6e84121c231fa3f697af2ae3'
  • Delete failed: 'cache__7627e3ae0680e262194e692d9e585aca'
  • Delete failed: 'cache__76e22fa1abeadea6ed25016b05dade54'
  • Delete failed: 'cache__7862109043b4e4560e439430b6bbf672'
  • Delete failed: 'cache__7f044b9858bedc8d27a3642aa90dd446'
  • Delete failed: 'cache__7f4f6d676584d4ea6ad6d7b4a3459810'
  • Delete failed: 'cache__7fde12ba2801f73d48f68aa14a3fde6c'
  • Delete failed: 'cache__93016dfdd114cbb603aadd164e9d4d3b'
  • Delete failed: 'cache__9a342c0fee331af73c9eb29e76224efa'
  • Delete failed: 'cache__9ded8c75eb4091f2a60a416a6e45d6de'
  • Delete failed: 'cache__9f8bd4e8fc6ed8b07945cf19d26dd349'
  • Delete failed: 'cache__a218ef0dc2a9df18e24398fce94a52cf'
  • Delete failed: 'cache__a9589137de428d087cf7d890afcec836'
  • Delete failed: 'cache__b14527d981f6aaa8b825ab61c047191d'
  • Delete failed: 'cache__b588f2f3b1c446cd987cb18ceb57b651'
  • Delete failed: 'cache__b9349ab54b150e89816f49979eab3baa'
  • Delete failed: 'cache__ba955b54c1c3b386f53813a32435fb76'
  • Delete failed: 'cache__babb14759344e231d655ab90f78192f0'
  • Delete failed: 'cache__bc0af921c7f0e53487e90427ea464b99'
  • Delete failed: 'cache__bd33fb7f339358fbfc1b3719e86d208e'
  • Delete failed: 'cache__beb2c1f164a818eb30f184118b00a491'
  • Delete failed: 'cache__c8b34566dad6456764e591ff80c458e9'
  • Delete failed: 'cache__d0b46c2feb9f407139f471cecba02de0'
  • Delete failed: 'cache__dc862fd4397cd77bd16012d5c36d761f'
  • Delete failed: 'cache__e190556de9df697aa63e87d676c0f47d'
  • Delete failed: 'cache__e2bf3c6a2852d5a630414700cc351abc'
  • Delete failed: 'cache__e6c9490fedb01eca0a4942ae20c8d528'
  • Delete failed: 'cache__ef90670a54b3858bf84e8fbb8f1b75b8'
  • Delete failed: 'cache__f95c9feb3b0efc9f461cc57a8969a942'

After the motor failure that was experienced in the first test flight a more comprehensively documented electronics brand was selected to wholly replace the previous motor and speed controller setup.

 

The documentation supplied with the new speed controller indicated that installation should be done in such a way that the heat sink will have a consistent flow of air across it. The base of the speed controller was quite uneven so a small plate was made out of carbon fiber and epoxied to the bottom of the speed controller.

 

The speed control was then secured to the plane using velcro.

 

Bench testing was then undertaken to verify the new power system's stability at a variety of duty cycles. The plane was secured to the bench and current measurements were taken using a clamp meter and temperature measurements were taken using a non contact thermometer.

 

Clamp meter

 

Overview of test setup

From the documentation provided by the motor manufacturer a 10x7 triple blade pusher propeller was selected to give maximum ground clearance for the propeller during landings, for larger propellers a folding design must be employed. As I am using a triple blade propeller and the manufacturer data is for twin blade propellers a rough conversion from triple blade 10x7 to twin blade equates to a 11x7, thus the following test results (highlighted in yellow) are expected.

           Scorpion SII 3026-890KV Prop Data
     Motor Wind - 7T Delta           Motor Kv  No-Load Current  Motor Resistance
(21 Strands of 0.25mm Wire)     890 RPM/Volt      Io = 1.90 Amps  Rm = 0.014 Ohms
Prop Prop  Input  Motor Watts  Prop Thrust Thurst Thrust
Manf. Size Voltage Amps Input RPM Grams Ounces G/W
APC 9 x 4.5 10.5 13.7 143.85 7850 850 29.98 5.91
APC 9 x 6 10.5 16.9 177.45 7750 950 33.51 5.35
APC 9 x 7.5 10.5 22.13 232.37 7575 975 34.39 4.2
APC 10 x 5 10.5 19.21 201.71 7700 1150 40.57 5.7
APC 10 x 7 10.5 24.39 256.1 7550 1175 41.45 4.59
APC 11 x 5.5 10.5 25.02 262.71 7525 1500 52.91 5.71
APC 11 x 7 10.5 31.6 331.8 7325 1600 56.44 4.82
APC 11 x 8 10.5 33.81 355.01 7300 1675 59.08 4.72
APC 11 x 8.5 10.5 37.78 396.69 7175 1600 56.44 4.03
APC 11 x 10 10.5 45.08 473.34 6950 1450 51.15 3.06
APC 12 x 6 10.5 35.21 369.71 7250 1975 69.67 5.34
APC 12 x 8 10.5 41.76 438.48 7025 2050 72.31 4.68
APC 12 x 10 10.5 53.4 560.7 6750 1925 67.9 3.43
APC 13 x 6.5 10.5 46.47 487.94 6950 2400 84.66 4.92
APC 13 x 8 10.5 50.24 527.52 6800 2325 82.01 4.41
APC 13 x 10 10.5 68.23 716.42 6325 2100 74.08 2.93
APC 14 x 7 10.5 58.43 613.52 6575 2800 98.77 4.56
APC 14 x 10 10.5 71.73 753.17 6225 2700 95.24 3.58

 

 

Test conditions and equipment

Battery PQ-6000XP 11.1V
Air Temp (degC) 15
Motor Scorpion 3026-890Kv
Speed Controller Scorpion 90A
Power wire gauge 12
Connector type EC3

 

Measurements were taken at the end of the "test run time" whilst the system was still running at the nominated duty cycle. Steady state was assumed after 5 minutes of continuous operation.

Duty Cycle Test run time (min) Amps drawn from battery Battery temp (degC) Connector temp (degC) Wiring temp (degC) Motor temp (degC)
50.00% 5 15.2 23 19 18 25
60.00% 5 18.6 23 20 18 28
70.00% 5 23.9 25 24 19 29
80.00% 1 33.5 27 24 20 31

Note: no wind speed recordings were achieved due to bearing failure in the wind speed meter.

These test results correlate with the expected data and no high temperatures were recorded anywhere in the power system. Thus the new system is acceptable for flight testing.

Finnaly an endurance test was performed by setting the throttle to 70% duty cycle and measuring the elapsed time until the low voltage cut on the speed controller is triggered (9V).

 

The low voltage cut was triggered at 19min and 44 seconds so from this data a flight time of approximately 15 minutes will be observed.

 
Banner
Banner