Hey
Can spmeone explain how AXI number their motors?
cheers

Why don't you email Hobby Lobby, they should be able to give you an explaination.

If memory serves, the first two digits are diameter, the next digits are length of the magnets and the final two digits are the number of winds. They seem to keep this a secret.

Thanks!

So, with all those numbers there is still no information on the power out-put?

For good information on AXI and other motors see the Great Electric Motor Test at http://www.flyingmodels.org/index_en.htm

Hi
I looked at the great motor test. What is the Effect (w) column? Is that the draw? What relation does it have to thrust?
cheers

W is Watts which is equal to Amps x Volts.

Watts is a metric unit of power. One horsepower = 746 watts. In the United States it is mostly used to measure electrical power but in the rest of the world, the power of gas engines is also rated in watts or kilowatts.

The definition of a watt is one newton of force x one meter per second. There is a common misperception that electrical units define the watt. Instead, the watt is used to define the volt. The definition of a volt is the amount of electrical potential that caused one amp of current to deliver one watt of power, thus you can measure watts by multiplying amps times volts, as long as you are dealing with direct current. Things get a little more complicated with alternating current and a non resistive load.

Thanks

Definition:
One watt is one joule of energy per second.

1 W = 1 J/s = 1 newton meter per second = 1 kg·m2·s−3

Origin:
The watt is named after James Watt for his contributions to the development of the steam engine, and was adopted by the Second Congress of the British Association for the Advancement of Science in 1889 and by the 11th Conférence Générale des Poids et Mesures in 1960.

MWe, MWt ---

Watt electrical (abbreviation: We) is a term that refers to power produced as electricity. SI prefixes can be used, for example megawatt electrical (MWe) and gigawatt electrical (GWe).

Watt thermal (abbreviation: Wt). This is a term that refers to thermal power produced. SI prefixes can be used, for example megawatt thermal (MWt) and gigawatt thermal (GWt). For example, a nuclear power plant might use a fission reactor to generate heat (thermal output) which creates steam to drive a turbine to generate electricity. See nuclear proliferation for discussion of a reactor that generates 200 MWt (50 MWe), and another reactor that generates 800 MWt (200 MWe).
__________________________________________________ _______________
The joule is a derived unit defined as the work done or energy required, to exert a force of one newton for a distance of one metre, so the same quantity may be referred to as a newton metre or newton-metre (also with meter spelling), with the symbol N·m or N m. It can also be written as kg·m2/s2. However, the newton metre is usually used as a measure of torque, not energy.

As a rough guide, 1 joule is the absolute minimum amount of energy required (on the surface of Earth) to lift a one kilogram object up by a height of 10 centimetres.

One joule is also:

The work required to move an electric charge of one coulomb through an electrical potential difference of one volt; or one coulomb volt, with the symbol C·V.
The work done to produce power of one watt continuously for one second; or one watt second (compare kilowatt-hour), with the symbol W·s

So basically its the power output of the motor?

Yes.

> So basically its the power output of the motor? <

I think it is power into the motor, not the output.

When comparing the power of an electric motor to that of a gas engine, keep in mind that when a manufacturer claims one horsepower for his .40 size glow engine, what he most likely means is that somewhere, on a cool crisp day, one of his engines managed to peak at one horsepower with an open exhaust and a tiny pylon racing prop that let the engine spin 17,000 rpm and it did it exactly one time in a row. There is a lot of pressure from marketing to inflate the rating as high as possible because the competitors are also doing it. Some engine makers, notibly Jett, simply don't give a horsepower rating because, to put it in Jett's words, "it's hard to beat the first liar".

Electric motor power is more of a "redline" than the absolute maximum. When a manufacturer rates his motor at 200 watts, it means that it is safe to use a prop and cell count that causes it to draw 200 watts of power. It can draw more for a short burst. Electrics also often use gear reducers to deliver their power to a slower turning more efficient prop. Because of this, you won't need a 746 watt motor to replace a plain bearing .40. 400 to 500 watts will do nicely.

I usually am sceptical about using mathematics to rate the output of any motor or engine. The reality is how many RPM can we get out of a prop. That is what power is all about. This is the most accurate manner in which we see manufacturers like Jett have used. BLE is most correct.

However the manufacturers rating in electric motors are rather more 'accurate' and the output is more 'realistic' than what we get in glow motors.