O.S. Brushless Motor 2820-950

Tower Stock# OSMG9494  •  Manufacturer Stock# 51010310
O.S. Brushless Motor 2820-950 (large view)
Notes from our tech department:
This is the 2820-950 .28 Brushless Electric Motor from O.S. Motors.


For .28 size airplanes
Stainless steel prop shaft
One front bearing
Rigid rear mounting design
Centrifugal fan design with angled ventilation holes draws air
through the motor and across the windings and magnets for improved
Two year limited warranty through Hobby Services beginning at date
of purchase


.28 Brushless Electric Motor with Backplate, four 3x4mm Mounting
Screws, 3mm Gold Plated Male Plugs attached to leads,
three 3mm Female Plugs with Shrink Wrap, Prop Adapter and
Instruction Sheet


30A brushless ESC such as the O.S. OCA-230 30A 25V, OSMM1110


Rated Voltage: 11.1
Rated Current: 22A
Maximum Current (5 sec): 30A
No Load Current: 0.9A/10V
Phase Resistance: 72 miliohms
Phase Inductance: 24
Maximum Efficiency: 80%
kV: 950
Poles: 16
Turns: 14
Shaft Diameter: 0.12" (3mm)
Shaft Length: 0.27" (7mm) front & rear
Weight: 2.8oz (80g)
Lead Wire Length: 1.6" (40mm)
Lead Wire Gauge: 17AWG
Length of Motor Can: 1.4" (36.5mm)
Diameter of Motor Can: 1.1" (28mm)
Length/rear of Motor Can to Prop Washer: 1.8" (46.7mm)
Prop Washer Diameter: 0.63" (16mm)
Thickness of Motor Mount: 0.078" (2mm)
Width of Motor Mount: 1.6" (40mm)
Height of Motor Mount: 1.6" (40mm)

Performance for this motor with different props and LiPo cells is as
follows (all data with O.S. OCA ESCs, and APC props):
Prop Size Voltage Current Watts Thrust Cells RPM
9x6E 12.6V 17.5A 221 1.07kg 3S 9,700
9x7.5E 12.6V 21.5A 271 1.06kg 3S 9,100
10x5E 12.6V 18.5A 233 1.22kg 3S 9,580
10x7E 12.6V 23.5A 296 1.29kg 3S 8,850
11.5.5E 12.6V 23.0A 290 1.49kg 3S 8,900
11x7E 12.6V 27.2A 343 1.53kg 3S 8,370
11x8.5E 12.6V 31.0A 391 1.51kg 3S 7,900
12x6E 12.6V 28.0A 353 1.71kg 3S 8,200
12x8E 12.6V 34.0A 428 1.73kg 3S 7,600
9x6SF 12.6V 25.7A 324 1.27kg 3S 8,600
10x3.8SF 12.6V 24.5A 309 1.35kg 3S 8,830
10x4.7SF 12.6V 25.0A 315 1.39kg 3S 8,610
10x7SF 12.6V 33.0A 416 1.52kg 3S 7,450
11x3.8SF 12.6V 28.0A 353 1.52kg 3S 8,350
11x4.7SF 12.6V 31.5A 397 1.52kg 3S 7,750
11x7SF 12.6V 38.0A 479 1.75kg 3S 6,870


Nomenclature is defined as follows:
0MA means 0.S. airplane motor
First two digits are the rotor diameter
Second two digits are the length of the magnets
Last digits indicate the kV of the motor

jxs 11/18/13

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