Hi fellas!

I'm considering building a powered glider, using a Supra wing. Is it complete and utter madness to do this with a direct drive outrunner?

Set up:
Weight (approx): 1600 gr / 58 oz
Wing area: 1054sq in
Motor: Turnigy C3548 approx. 600W 11x8 prop

All input is most welcome!

Cheers
Patrik

Originally Posted by century_series

...... Is it complete and utter madness to do this with a direct drive outrunner?.....

Not at all. It's about the same weight,wing area as my Bird of Time. I'm running a Scorpion ESC with a RimFire 35-48-1300KV Outrunner turning a 12 x 8 folder pushing 690 watts in direct drive. Works very well indeed.

Thanks Leadchucker!
Forgot to mention it's an 800kv motor. When it sat in a Pitts it was best suited with an 11x8. I'll try some different props but the main question is answered, it'll work.
Maybe this will turn into a build log...

/Patrik

All depends on what kind of climb you want, what battery you plan to use and how many amps the motor will take.

Using a 4S on an 11X8 prop that motor should pull about 32 amps/460 watts for about 100 watts/pound at 70 ounces all up weight. That seems more likely for an electric Supra. 60 oz would be about right for a supra in pure glider form.

It will give you about a 70 to 80 degree climb.

1800 mah pack would work, but I would target a 2400 mah pack. That should give you 6-8 climbs/reclimbs with a little reserve.

I am putting a Supra E together with an MVVS Glider electric motor -- it is an outrunner where the outrunner part is inside an external case. Real slick, but not very cheap.

I have been flying a Hyperion 3025-06 in my AVA-E with a 3S battery and a 13x7 RF prop. Climb rate with a 42mm hub is about 3500 fpm (straight up like a rocket). The plane weighs about 55 oz.

I have bench tested a new Hyperion 3025-08 with a 3S battery and a 16x8 prop and it pulls about 100 oz static thrust. 600+ watts. Based on experience and interpolating my data with Motocalc, it should pull your Supra up at rates exceeding 2500 fpm -- maybe as much as 3000 fpm.

These Hyperions are real gems for powered gliders. They are outrunners with tapered nose pieces which both fit narrower glider noses and which support the rotor a little better. In a narrow nose, however, you will still have to make provisions to lead the wires past the motor. Either with some kind of bulge or by simply leading the wires out and then back in behind the motor. I have used both on various outrunner motors.

Unless you are looking for the absolute maximum power system efficiency of a geared inrunner, these motors are hard to beat. And for what you get, they are not very expensive ($90 or so). One source is allerc.com.

While most of us do not need FAI rockets, I have found that the little added power these motors add results in gliders which will fly straight out of your hands in any conditions with no muss or fuss. Launching AVA is pretty well a hands-off affair. You hold it over your head, turn on the motor and let go. No toss, no problem accelerating to airspeed -- just let it go and fly.

Happy Landings,

Don

Thanks guys!
I just realized I should have looked around for e.g. MotoCalc and done a little more research. Thanks for sharing your experiences!
I will definately continue with this concept and start initial sizing of tailplanes et cetera. Also lengthen the pod a bit to enable a longer, wider and stronger "stand" for the wing.
More CAD-pix to come...

Cheers
Patrik

Don,

Remember that AMA imposes a 250 mph speed limit.

Originally Posted by century_series

Thanks guys!
I just realized I should have looked around for e.g. MotoCalc and done a little more research. Thanks for sharing your experiences!
I will definately continue with this concept and start initial sizing of tailplanes et cetera. Also lengthen the pod a bit to enable a longer, wider and stronger "stand" for the wing.
More CAD-pix to come...

Cheers
Patrik

If you are interested, you can buy wing cores or finished bagged Supra wings and tail from http://www.stealthplaneworks.com/Suprawings.aspx

Originally Posted by aeajr

Don,

Remember that AMA imposes a 250 mph speed limit.

Ah, I bet that doesn't apply to swedish airspace!

Originally Posted by aeajr

If you are interested, you can buy wing cores or finished bagged Supra wings and tail from http://www.stealthplaneworks.com/Suprawings.aspx :

Yes I saw that and I'm tempted going for the cores. But I'm also going to try running a few sims in XFoil with an HQ airfoil. If that doesn't work I'll go for the cores.

Cheers
Pat

Originally Posted by century_series

Ah, I bet that doesn't apply to swedish airspace!

Pat

You need one of those Saab Vigen motors.

Hi together,
just maidened my e-supra yesterday ! Wonderful !
set up:
-Plettenberg 220/30 (460k/v) with 270gr
-Neu 2200 60C lipo 4s
-CC 100 ICE light controller
-RFM 21X13 prop with 38mm spinner
-all up weight 2420gr (10gr lead in the tail required to get cg at around 93mm )
-100 amps gives 1500watts for wonderful verticals !
Dreamplane for me with a huge flight envelope !
see you
Hans

Originally Posted by aeajr

Don,

Remember that AMA imposes a 250 mph speed limit.

What?

Originally Posted by aeajr

You need one of those Saab Vigen motors.

Hmm, do I connect that to a "LiPo" or "LiFe"!?

Hello. Jag asked samma thing för my Ava-E and mitt result blev very bra, so här is tråden: http://www.rcgroups.com/forums/showthread.php?t=1284580