rsrogers

My Feedback: (10)

Hey guys I'm new to electrics & just got my first one flying (foamy) and have a question concerning the AXI motors.

When I purchased my set-up I went soley on recomendation from the guy at the hobby shop. Now that this stuff has impressed me I want to know more!!

The motor I have is the AXI 2212/26 and my qusetion is how do you size (??) these things as in what size for what application.

Does the 22 , 12 , or 26 or all three have something to do with it?

For most this may be a simple question but please fill me in!!

Thanks,
Steve

BadSplice

My Feedback: (1)

Im not real familliar with AXI, but as I understand it the 2212 is the size of the motor, maybe even the dimentions, and the 26 is how many windings in the coils. less windings =more power. more windings =more efficient

gwh

In your example of a AXI 2212/26, the 22 is the diameter of the Stator in mm, the 12 is the length of the stator in mm, the 26 is the windings. The lower the winding number the higher the Kv rating will be. Thus a 2212/24 has a higher Kv than a 2212/26 . The higher Kv motor is sometimes referred to as being a hotter motor or hotter wind.

Kv is the numbers of rpms per volt. For example a motor with a Kv of 1000 will spin 5,000 rpm on an input voltage of 5 volts (5v*1000rpm/v=5,000rpm).

A good start for sizing motor and plane is to use a rule of thumb of 80 watts/pound for a trainer, 100 watts/pound for a sport plane and 150 watts/pound for 3D.

Take the max volts * amps that your motor will handle this will give you max watts. (v*A=watts) Now divide this by the proper power loading and you will get the maximum weight for your plane.

As a general rule the 2208 series replaces a speed 400 direct drive motor or .049 glow motor.
As a general rule the 2212 series replaces a speed 400 geared/480 direct drive motor or .10 glow motor.
As a general rule the 2808 series replaces a gearged 480 geared motor or .15 glow motor.
As a general rule the 2814 series replaces a speed 500 direct drive motor or .20 glow motor.
As a general rule the 2820 series replaces a .25 glow motor.
As a general rule the 2826 series replaces a .35 glow motor.
As a general rule the 4120 series replaces a .45 glow motor.
As a general rule the 4130 series replaces a .61 glow motor.

All glow motors referenced are 2 stroke.

rsrogers

My Feedback: (10)

Thanks guys this is a tremendous help.

Jean13704

There is a lot of useful info on each of the Axi motors on this web site.

http://www.modelmotors.cz/index.php?id=en&nc=produkty

rsrogers

My Feedback: (10)

Good Site!!

Bob757FL

My Feedback: (15)

Don't feel like you are the only one that doesn't have a clue but wants to! I had exactly the same questions until reading this. Many of the older guys at the field feel inimidated by all of it. Its like a different language when speaking electrics. The ones who have jumped in are having a ball. I'm going to figure enough out to do the same thing. Good luck and thanks for posting your question.
Bob

rsrogers

My Feedback: (10)

Good luck yourself Bob.

What would we do without the GREAT people in this hobby who unselfishly share there knowledge???

ddub23

Thanks for asking the question Steve. I'm using the SXI 2212/34 on my foamy and have always wondered... Too embarassed to ask [sm=wink.gif]

Great info gwh! Happy flying

Derrick

Matt Kirsch

My Feedback: (21)

I hate to complicate things, but oversimplifying like GWH did can get you into trouble. That is, you've spent beaucoup bucks on this razzle-dazzle LiPoly and brushless setup, and the plane will barely taxi, for example.

To say that a motor in and of itself is somehow "equivalent" to a glow engine is misleading. That often misleads people into thinking that the motor is equivalent to a glow engine regardless of prop size or battery. If you look at the charts for the 4120/14, for example, they show a wide range of power outputs, from around 300 Watts to over 700 Watts, IIRC. On a typical 6lb .40-size sport plane, that would give you a power loading of 50 W/lb (barely climbs) to 115 W/lb (highly aerobatic)

The truth of the matter is that the battery is the most important piece in the puzzle. Volts are your cubic inches. You can have the biggest, heaviest motor in existence, but without enough power going to it from the battery, it's a paperweight.

You can go with GWRs recommendations, as long as you keep it in the back of your mind that there are caveats.

rsrogers

My Feedback: (10)

Thanks for that input Matt. I pretty much new that part but hopefully it will benifit others.

Matt Kirsch

My Feedback: (21)

I hate to complicate things, but oversimplifying like GWH did can get you into trouble. That is, you've spent beaucoup bucks on this razzle-dazzle LiPoly and brushless setup, and the plane will barely taxi, for example.

To say that a motor in and of itself is somehow "equivalent" to a glow engine is misleading. That often misleads people into thinking that the motor is equivalent to a glow engine regardless of prop size or battery. If you look at the charts for the 4120/14, for example, they show a wide range of power outputs, from around 300 Watts to over 700 Watts, IIRC. On a typical 6lb .40-size sport plane, that would give you a power loading of 50 W/lb (barely climbs) to 115 W/lb (highly aerobatic)

The truth of the matter is that the battery is the most important piece in the puzzle. Volts are your cubic inches. You can have the biggest, heaviest motor in existence, but without enough power going to it from the battery, it's a paperweight.

You can go with GWRs recommendations, as long as you keep it in the back of your mind that there are caveats.