Those on the Beginners Forum told me those on the Electric Flight Forum know more about this, so here goes.

OK, I read & follow all kinds of posts, different forums, several mags, helpful info on dealer sites and much more, and I still don't know what all the number mean. For example, 20, 40, 60, 90 all relate to size of Planes and Heli's. Those number do not mean a thing to me as I find no relationship to any real measurement. How or where can I learn how to relate these numbers to some real life specific measurement.

Next, is motor or engine designations. I understand (basically) about KV (RPM per volt) I think. However I see numbers like 2800/12 or /10 and on and on. Are these only a manufactuers designation of a specific product ie: size, power, etc motor or engine? How can we new to the hobby beginners learn about such information? Where do we go? How do we calculate the power needed to fly a given model and the power of any specific powerplant? Some motors are 21mm, 28mm who knows what else? I understand these are metric measurements and lengths are also in mm. I can convert and measure these any way necessary. My problem is that I can't relate these figures to what may be needed for a specific application. How does anyone compare two or more items when totally diferent number are used to describe them? Makes no sense to me.

I have for example exchanged a GWS 400 motor for a 200W motor from another maker for my new plane. I am told it is intended for my plane, but what does 200W mean in terms of power, KV, Amps and any other related term? How does it stack up to the EP400 from GWS? I am thoroughly confused at this point. I would like to find answers to these questions and learn to work all these numbers into a single related, useful and understandable system as much as possible. I know different Mfg's may have different ways of ID'ing their products but AXI, Neu, Medusa and all the rest are related and I need to somehow make sense of it all.

If there are places to go to learn more about these things I would appreciate knowing. I am sure others are in the same boat. It is all very confusing, but fun anyway.

I know it will come with time but I hate to just have a blank stare when some one reels off the numbers for their Plane, Heli or Sailplane. I'm impressed all to heck when a guy tells me I have a 30 at home, also a 90 Heli and I'm building a 50 scale using a 3700KV motor. What?