Air Craft Data Sheet - BL4-15 Series 6-Pole Brushless Motors

RCer
BL4-15 Brushless
WARP 4 Series
Pricing HERE

The New Rcer WARP 4 Hi-Torque 6-Pole Brushless motors are the new power king in their class. Rugged construction, 400 and 480-class mounting positions, and near identical dimensions and weight to Speed 400 brushed motors all make the WARP 4 a "drop-in" replacement for Speed 400-480 direct drive applications. The 2-turn and 3-turn are excellent in ducted fans, and their higher Kv also makes them well-suited to geared applications, such as 2M gliders or large E3D. The 3-turn is also a favorite for direct drive super-fast models at up to 26A continuous on 3S lithium*. The 4-turn to 6-turn are usually run direct-drive in 300 to 480-Class airplanes. 3.5mm Gold Bullet Connectors, 3ea Male/Female, are included with each motor.

See video of the 3-turn motor in a F22 foamie pusher jet here (BL4-15-3, PQ-2600-3S, GR 5.5x4.5 speed prop)

The F22 pilot remarked "During a five-minute flight similar to the one in the video, the F22 lands with the motor just warm to the touch!"
[note: this is not necessarily a green light to ignore the manufacturer max ratings... says NipponDave]

The power advantage enjoyed by the BL4 15 Series motors is due to carefully shaped silicate-iron stators - which maximize wound copper and minimize magnetic shorting between the plates - plus extremely powerful, optimally-shaped magnets on the rotor. Kevlar sleeve on the rotor allows the BL4 16 series to turn up to 40,000 rpm continuously.

It is easy to see the Warp 4 advantage, when you notice that the internal resistance of the motors is identical to other 6-pole motors in the same class, but the Kv is much lower due to the stronger magnets. That's why the Warp 4 motor can turn a larger (or higher pitch) prop than the competition at the same amperage and voltage. Larger props add even more to the overall effciency of a power system.

Not only are the Warp 4 the most efficient motor in their class, they are also the shortest, at 34.5mm, and lightest, at only 73 grams (without connectors attached, to compare with other brands).

The hard 3mm output shaft is suited to rough landings in direct-drive models. Pinions for the Maxon 4.4:1 Ceramic gearbox are available for the BL4, along with new 68mm high-performance EDF fans with 3mm adapters.

The BL4 come with two sets of mounting holes, to cover all applications:
* 2x M2.6 holes@16mm spacing (400 spec)
* 2x M3.0 holes@19mm spacing (480 spec)

Specifications:

Turns	Kv	NoLoad Current	W	Max RPM	Weight (grams)	Click Links for Test Data*
2	3880	4.10A	0.012	40000	74.5	Prop Tests 2-Turn
3	2580	2.00A	0.026	40000	74.5	Prop Tests 3-Turn
4	1810	1.30A	0.045	40000	74.5	Prop Tests 4-Turn
5	1430	0.95A	0.068	40000	74.5	Prop Tests 5-Turn
6	1190	0.80A	0.110	40000	74.5	Prop Tests 6-Turn

Note: Prop tests which show amperage exceeding spec are for your information only, but not recommended for that combination of battery, propeller, and motor.

*Adobe Acrobat Reader required for PDF Format Test Data Files

Ratings:

Turns	Max A Continuous	Max W 5 minutes	Max A 20 sec	Model Type / Example Setups
2	32A	260W	60A	Insane EDF, Pylon APC 4.1x4.1 30A~43A 1.5-2.0M LMR Glider w/4.4:1 Maxon 35A~60A
3	26A	260W	40A	EDF, Pylon 4.7x4.7 20A~26A Very Fast Models - Pusher Jets, etc 1.5-2.5M Gliders w/4.4:1 Maxon Gearbox 35A
4	22A	260W	30A	Fast Models 400g - 750g PQ-1800-3S, APC E 6x4, 15.6A
5	18A	260W	24A	Fast to Medium-Speed Models 400g~900g PQ-1800-3S, APC E 7x5, 16.0A 1.5M Gliders GR 8x4.5, 9.6V KAN 1050 16A
6	14A	260W	18A	Medium-Speed Models 400g~1000g 9.6V KAN 1050, APC E 9x6, 13.0A 1.5M Gliders 9.6V KAN 1050, GR 9x5, 13.3A 8160rpm

Note that all the BL4-15 Warp4 motors have the same max power(W) rating for 5 minutes, of 260W. While this is accurate in fact, in practice we usually limit input voltage in models of the 400-480 class to 12 volts (10 cell NiX) or 11.1V (3S Lithium). To go higher than this voltage is ONLY recommended when the speed controller BEC is disabled and receiver and servos are powered by an additional 4.8V battery or switching power system (S-BEC). Most users prefer the simplicty and light weight of the speed-controller BEC, so let's assume that 12V is max voltage for all of these motors, for most applications. In that case, the 6-Turn motor would be limited by available voltage (12V) and the max continuous current rating (14A) to:

12V * 14A = 168W

That's still a LOT of watts for a 400-480 class model, and is delivered with high final efficiency since the 6T motor can turn a relatively large propeller, which minimizes losses at the prop itself. Large diameter / high pitch props turning slowly lose less than small props turning very quickly...

Likewise, note that the 2T motor is rated for 32A max continuous. At 12V, however, the max continuous amperage would be limited by the continuous rated power of 260W, like this: 260W / 12V = 21.66A. Since the motor is really quite efficient up to and even beyond 40A, its best used in 2S Lithium or 7-cell NiX applications direct drive, or as a geared limited-motor-run setup in gliders for absurd power/weight performance in 20-second bursts.

So it's best to avoid the misconception that high Kv motors necessarily mean more power, and much better to choose the propeller size that matches your model type first. Next determine which motor can turn that prop, using the battery you've chosen, at the amperage which suits your battery. For high-quality 1000mAh-class NiMH, like KAN 1050, the most effcient amperage is around 12-13A continuous, up to 17A or so for models using of throttle management. For lithium batteries, you'll get best performance overall, in terms of delivered voltage and charge cycles, if you choose a propeller and motor combination to draw 70%~80% of rated continuous current. [for a 2000mAh pack rated at 10C (20A), for example, best practice is a continuous current of 14A~16A]. These recommendations may seem conservative, when compared to user reports, but they are intended to deliver both very strong performance, and long battery life. Of course, you can use batteries at their rated maximums, but in most cases it is not necessary if the battery, motor, and propeller are properly matched to the model you fly...

Suggested 3mm Prop Adapter for Warp4 motors

----------------------------------------------------------

All the content on this page is the sole property of Air Craft and may not be distributed, copied, paraphrased, or used in any way by any other commercial entity - (May 24, 2004）