The Ultrafly "A" series motors benefit from the natural torque and cooling advantages of the Outrunner motor design. However, the Ultrafly motors are also wound with low-resistance wire for higher "Kv". That means that, compared to other Outrunners, they can sustain higher current levels at higher efficiency, and take advantage of further gains from gearing. The Ultrafly gearbox supplied with the motor & gearbox sets (pictured right side above - does NOT include prop adapter, use MPJ-8030 or MPJ-8031) offers these features:

• Four Spur and Pinion Gear Sets Included - Ratios:1.93, 2.38, 3.0, 3.89
• Front and Rear Ball-bearings
• Super-hard 3mm output shaft
• Heavy-duty Gearbox Frame for 10x10mm Stick Mount

The UltraFly gearbox measures 31mm across at the widest point. The "P" pinion for 3.89:1 ratio (widest pinion), measures 29mm across.

Here are some weights for comparison:

Ultrafly A/30 + Ultrafly Gearbox            =  70.8g  (160W max in)
GWS EPS-350C Motor + Gearbox          =  61.8g  (65W max in)
Hacker B20 S Motor + EPS-350 Gearbox =  59.4g  (100W max in)
Hacker B20 L Motor + EPS-400 Gearbox =  91.3g  (180W max in)
GWS EPS-400 Gearbox alone                =  22.6g

So you can see that the Ultrafly set nicely bridges the gap between the low-power brushed 300 and highest power "400-class" set, in terms of weight.  Replacing an EPS-350C set with the Ultrafly, for example, would only add 9g, or less than 3% to the all-up weight of the model, while allowing up to triple the power output at the prop, given that the A/30 has both higher efficiency and max power input rating.

While the Ultrafly "A" motors are intended primarily as geared solutions, the A/30/24 (Kv 2400) can also turn up to a 6x4 propeller on direct drive. We haven't tested the A/30/29 (Kv 2900) direct yet, but it is likely a bit too high in Kv for all but very small, very fast models (pylon!). Here's some preliminary data for the A/30/24 direct drive (with soft timing):

A/30/24 DIRECT

And here are some numbers on the 3.89:1 Gearbox. This data is from the factory, using a lab power supply. For Lithium polymer 3S, average the 10V and 9V data to estimate amperage. We'll have motor constants and more prop tests soon.

Ultrafly A/30/29 KV=2900   3.89:1 Geared

Ultrafly A/30/24 KV=2400   3.89:1 Geared

Use and Notes:

Gearbox assembly: The motors with gearbox are supplied with gearbox unassembled.  Click here for instructions.

Speed Controller: You must use a brushless, sensorless speed controller.  We recommend the Castle Creations Phoenix 25 to Phoenix 35, or Jeti ADVANCE 18-3P to 30-3P.  Use MP Jet 2.5mm Gold connectors between motor and controller. (Jeti 30-3P comes with 3.5mm Gold female connectors attached, so you need only the matching 3.5mm Gold male - 3 pcs)

Cooling: You must provide proper cooling to avoid exceeding the 100-degree-celcius limit. Overheating will damage magnets and windings, and is not covered under warranty.

Over current: Use an ammeter to check for appropriate battery cell count and propeller size. When changing gear ratio, propeller size, or battery type you must measure the current. You must limit current to the “continuous” specifications above, or less, to avoid damage to the motor. Reduce prop size or battery cell count to reduce current.

Rotation: Switch any two of the three wires between speed controller and motor to reverse motor direction. NEVER reverse polarity from battery to speed controller.

Limited Warranty: Ultrafly brushless motors have a one-year, limited warranty from date of purchase. All motors are guaranteed to be free from manufacturing defects for one year.  The warranty does not cover over-current, over-temperature, or crash damage. The customer must properly cool the motor and keep the current and input wattage within specifications. Improper use of the motor can be determined in service and will not be covered in the warranty.