Originally Posted by crashawk
most people around here can't use formulas, it's easier to remember what the max watts recomended by the manufacturer is, and most have a max wattage, not max amps since if they rated it at x amps for say, 2 cells someone would try to run it at the same amps on 4 cells and very quickly burn it up. it's all in the watts. lol.
either way you look at it though, I still recomend a meter if you are going to experiment. a good way to measure the temp of the stator is a good idea too if you are really going to push it.
I'm sure it works for you if you are guided by Watts. That is a safe method and there's nothing wrong with that. But... there are some of us who like to push our motors and how do we know what the limit for a motor is? We go by the amps, since amps determines the heat generated in a motor - not Watts! As stated before, the other determining factor is Rm (motor resistance). Finding (or winding) a motor with low Rm is of utmost importance. That is what drives the guys on this forum: http://www.helifreak.com/forumdisplay.php?f=291
These days I often run my motors at double the specified "max Wattage" by using more cells, but staying within the amps limit. Obviously, it often means using a different motor with lower Kv, depending on the cell-count and prop size I want to use.
When I started learning about electric motors, I was also stuck in the "Watts-way of thinking". But fortunately some motor manufacturers stated max amps (not max Watts). That got me thinking and then I finally started understanding how a motor really works. So give it time -You'll come around (hopefully).