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Old 03-11-2015, 01:51 PM
Ochroma Pyramidale Tekton
FlyWheel's Avatar
Join Date: Jul 2007
Location: Blackstock, South Carolina
Posts: 3,029
Thumbs up Thanks for y'alls help!

I finally decided on the Hyperion HP-Zs2213-22. It's not as powerful as even the lowest Axi I had posted, but it should certainly be good enough for the coolliner E-glider I'm planning to build. It's also smaller (28MM vs. 35MM) and the resulting plane will be even lighter. Which is better for a glider!

Sorry Larry, but I couldn't get the $16 one you lead me to as their payment page kept shutting down my browsers. I tried four times, but neither Explorer nor Chrome could deal with it so I got one from National Hobbies instead. I also ordered a Jeti 30A ESC from Esprit. Again, 30 amps is probably more than this Hype will ever pull, but I figured better safe...

Best result I got from MotoCalc on this motor was from 3 cells and a 10x5 prop (I can also use a 10x6 if that's not enough). I can get those from my (NS)LHS

Originally Posted by MotoCalc (abridged opinion)
Airframe: Skimmer 600; 532sq.in; 32oz (guesstimated) RTF; 8.7oz/sq.ft
Motor: Hyperion Zs2213-22; 862rpm/V
Battery: 3 cell Lithium
Prop; 10x5 direct drive.
Stats: 59 W/lb in; 48 W/lb out; 15mph stall; 19mph opt @ 68% (29:41, 73F); 23mph level @ 80% (22:38, 76F); 626ft/min @ 21.7

Power System Notes:

The full-throttle motor current at the best lift-to-drag ratio airspeed (9.6A) falls approximately between the motor's maximum efficiency current (6.4A) and its current at theoretical maximum output (44.4A), thus making effective use of the motor.

Possible Aerodynamic Problems:

The static pitch speed (34mph) is less than 2.5 times the stall speed (15mph), which may result in reduced performance at typical flying speeds and a low maximum speed. This situation is usually acceptable for an electric sailplane or other slow-flying model.
Pitch speed can be increased by using a higher pitched and/or smaller diameter propeller, a higher cell count, or some combination of these methods.

Aerodynamic Notes:

With a wing loading of 8.7oz/sq.ft, a model of this size will have very sedate flying characteristics. It will be suitable for relaxed flying, in calm or very light wind conditions.
The static thrust (23.5oz) to weight (32oz) ratio is 0.73:1, which will result in very short take-off runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and steep climb-outs.
At the best lift-to-drag ratio airspeed, the excess-thrust (11.4oz) to weight (32oz) ratio is 0.36:1, which will give strong climbs and rapid acceleration. This model will most likely readily loop from level flight, and have sufficient in-flight thrust for many aerobatic maneuvers.
SO... I have my motor, my ESC, battery, prop, receiver and servos. All before I even started building. That's a first for me!

Last edited by FlyWheel; 03-11-2015 at 02:23 PM.
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