Motor comparison

1717-03 Motor (distributed by WES-technic, Faulhaber or Micro-Mo) - Indicative price: 33 US$.

Motor 1717-03				Prop. WES 26x12				Gearbox 1 / 7,5
Rotation speed			rpm	1400	1800	2200	2400	2700
Measured voltage			V	3	4	5,1	5,9	6,6
Measured current			A	0,28	0,45	0,66	0,84	0,98
Electrical power			W	0,84	1,8	3,37	4,96	6,47
Motor 1717-03				Prop. WES 23x12				Gearbox 1 / 11,8
Rotation speed			rpm	1300	1900	2200	2400	2700	3000
Measured voltage			V	4	6,2	7,2	7,8	8,8	10
Measured current			A	0,13	0,27	0,36	0,42	0,52	0,66
Electrical power			W	0,52	1,67	2,59	3,28	4,58	6,60
Motor 1717-03				Prop. WES 23x12				Gearbox 1 / 7,5
Rotation speed			rpm	1400	1900	2200	2400	2700	3000
Measured voltage			V	3	4	4,9	5,4	6,2	7,2
Measured current			A	0,23	0,37	0,51	0,59	0,75	0,91
Electrical power			W	0,69	1,48	2,50	3,19	4,65	6,55
Motor 1717-03				Prop. WES 23x12				Gearbox 1 / 6
Rotation speed			rpm	1600	2100	2200	2400	2700	3000
Measured voltage			V	3	4	4,2	4,8	5,5	6,4
Measured current			A	0,34	0,54	0,59	0,71	0,88	1,1
Electrical power			W	1,02	2,16	2,48	3,41	4,84	7,04

MK426A Motor (origin TAIWAN) - Indicative price: 2$ (yes, two bucks!).

Motor MK426A				Prop. WES 26x12				Gearbox 1 / 6
Rotation speed			rpm		1800	2200	2400	2700
Measured voltage			V		4,4	5,7	6,6	7,9
Measured current			A		0,5	0,74	0,86	1,05
Electrical power			W		2,2	4,22	5,68	8,3
Motor MK426A				Prop. WES 23x12				Gearbox 1 / 6
Rotation speed			rpm			2200	2400	2700	3000
Measured voltage			V			5,1	5,8	7	8,4
Measured current			A			0,48	0,56	0,74	0,89
Electrical power			W			2,45	3,25	5,18	7,48

DC 5-2.4 Motor (distributed by WES-technic) - Indicative price: 26 US$.

Motor DC 5-2.4				Prop. WES 23x12				Gearbox 1 / 7,5
Rotation speed			rpm			2200	2400	2700	3000	3200
Measured voltage			V			5,3	5,7	7,2	8	8,8
Measured current			A			0,52	0,63	0,82	1	1,2
Electrical power			W			2,76	3,59	5,90	8	10,56
Motor DC 5-2.4				Prop. WES 23x12				Gearbox 1 / 6,7
Rotation speed			rpm			2200	2400	2700	3000
Measured voltage			V			4,9	5,5	6,6	7,5
Measured current			A			0,61	0,74	0,94	1,2
Electrical power			W			2,99	4,07	6,20	9,00
Motor DC 5-2.4				Prop. WES 20x10				Gearbox 1 / 6,7
Rotation speed			rpm		1900	2200	2400	2700	3000	3300	3600
Measured voltage			V		3,5	4,2	4,9	5,6	6,5	7,2	8,4
Measured current			A		0,3	0,4	0,5	0,62	0,76	0,89	1,1
Electrical power			W		1,05	1,68	2,45	3,47	4,94	6,41	9,24

1319-03 Motor (distributed by WES-technic, Faulhaber or Micro-Mo) - Indicative price: 44 US$.

Motor 1319-03				Prop. WES 20x10				Gearbox 1 / 6,3
Rotation speed			rpm		1900	2200	2400	2700	3000	3300	3700
Measured voltage			V		3,2	3,7	4,3	4,9	5,4	6,1	7,2
Measured current			A		0,3	0,4	0,5	0,6	0,7	0,82	1,1
Electrical power			W		0,96	1,48	2,15	2,94	3,78	5	7,92

Servo Hitech 605 BB motor - Indicative price: 18 US$.

Motor Servo Hitech 605 BB				FF white Prop. 25 cm				Gearbox 1 / 6
Rotation speed			rpm			1600	1700	1800
Measured voltage			V			7	8	9
Measured current			A			0,86	1,2	1,4
Electrical power			W			6,02	9,6	12,6

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Some additional comments:

- All values presented hereabove are actual measured values. The rotation speed is the speed of the propeller.
- All above set-ups give nice flights with the XXS-Hi-tech (between 2000 and 3000 rpm with 1717, 1319 et DC 5-2.4 coreless motors and MK426A standard motor and between 1600 and 1800 rpm with servo 605 BB standard motor).
- At a given speed and a given propeller, any increase of the gear ratio decreases the motor current (and therefore increases the flight duration with a given battery) and increases the required voltage for that speed (and therefore the rotation speed of the motor shaft).
- For indoor use, motors are overrun, with a very short life time as a result. High current (motor over heating, especially at collector and brushes level) and high motor rotation speed (2 or 3 times the maximum value given by the manufacturer) are the main reasons for wearing. However, in my opinion, brushes wearing due to overheating (too high current) is by far the main cause and, other things being equal, we should use a gear ratio as high as possible (compatible with the maximum voltage of the battery).

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My own conclusions:

Taking into account all the above, I use now the following setups:

- DC 5-2.4 motor (mass: 10 g) - prop. WES 20x10 - gear 1/7,5 - 7 x 50 mAh cells: for indoor less than 100 g. You could be tempted to overrun this nice little motor, light and powerful. By experience, it seems mandatory to limit the flight duration to 3 to 4 minutes (50 mAh max. battery) otherwise brushes will not resist for long. Field life times vary from 4 hours to 30 hours depending on use... A good alternative option would be the 1319-03 Faulhaber motor (same mass, similar specification) which should be more robust but more expensive.

- 1717-03 motor (mass: 17 g) - prop. WES 20x10 or 23x12 - gear 1/7,5 or 1/10 - 7 x 120 mAh cells: for indoor between 100 and 200 grammes. I now use this setup on my own XXS-Hi tech.

- MK426A motor (mass: 18 g) - prop. WES 26x12 - gear 1/6 - 7 x 120 mAh cells: A setup almost as powerful as the previous one but much cheaper, for indoor between 100 and 150 grammes.

- 1717-03 motor (mass: 17 g) - prop. WES 23x12 or 26x12 - gear 1/10 or 1/11,8 - 7 x 120 mAh cells: for indoor between 150 and 250 grammes.

- Mabuchi FK-180SH motor (mass: 33 g) - white or yellow FF propeller - 7 x 250 mAh cells: for indoor between 220 and 350 grammes. It is what I use on my Drosophile.