Well I just tried out my new Glo-Bee tach. I actually took my reading from the paddles with the blades removed. It's a bit safer that way. As a light source I used my led flashlight. I think it worked well because the tach zeroed out right away when pointed at the flashlight.

Anyway with [link=https://www.unitedhobbies.com/UNITEDHOBBIES/store/comersus_viewItem.asp?idProduct=3849]this[/link] motor my Axe's RPM's in a hover are 2880 and at full throttle 3120. [X(]TOOOO HIGH!!![X(]
I used DarkHorses BL calculator, but since the Axe isn't up there I'm thinking that to spite the fact I got the tooth-counts right I used the hornet set-up values so the gear circumferences were probably off. Anyway I'm going to try [link=https://www.unitedhobbies.com/UNITEDHOBBIES/store/comersus_viewItem.asp?idProduct=4875]this[/link] motor next and see what happens. I wish there was a better method other than trial and error.