Thread Tools
May 09, 2009, 12:29 PM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP
Thanks for the nice replies, guys! Much appreciated.

kdahlhaus, yeah, I know what you mean. Nothing wrong with high-alpha per se, but I wanted to design something that was flying more on the airfoil (more Bernoulli, less Newton) rather than primarily off of the incidence of the wing (more Newton, less Bernoulli).

I recently built a Dart, and it's definitely a cool plane, but after flying it initially in a larger space, I knew there was no way it would fly in my backyard - well, at least with my piloting skills (which admittedly aren't all that great).

Hope you enjoy the BYOB when you get a chance to put one together.
Sign up now
to remove ads between posts
May 09, 2009, 11:45 PM
plane obsessed
Cody WIlson's Avatar
Very nice- thanks for sharing your build!
May 13, 2009, 11:00 AM
Registered User
Nice plane. How do you think it would do if I substituted FFF for the depron, using the same electronics?
May 13, 2009, 11:31 AM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP
Hi miniman - thanks for the question. A couple things:

One, I did consider a FFF version of this plane. I don't think the same size using the same electronics and just simply switching to FFF would work too well though, for a couple reasons. A.) it's heavier and B.) it's much thicker than most of the Depron used in the plane, which is going to substantially increase drag, so the little 10g outrunner may not be able to overcome all that extra weight and drag. Now, in VERY calm conditions - it might. So I'm not saying "no, it won't work" - I'm saying I don't think it will work very well, having never actually tried that.

(A good point to keep in mind is that our foam planes will "just barely fly" at 30 watts per pound, and fly minimally at 50 watts per pound. Having tested my 500mAh battery recently - which is dying - I realized I was only getting about 35 watts per pound of thrust at the tail end of each flight. Add the extra weight and drag of FFF, and you see why I'm dubious about it's "flightworthiness" at the 26" wingspan using FFF! But I digress...)

Secondly, this would make a good plane scaled UP somewhat, I think. I intend to get to this at some point, but wanted to make a plane that can fly in a VERY small space - hence the initial Depron offering. I think scaling it up will require a larger area. Of course, I realize everyone's flying space is different than my backyard. But at a 32" or 36" wingspan, it will likely make for a very good plane using, for example, a slightly larger brushless outrunner like the little Blue Wonders or something similar.

Give me a few days to get the plans scaled up to a larger version, and I'll try and get that not only posted, but also built for a FFF version - I think I have sufficient materials laying around. But I'm not sure the present size with the same electronics will handle it too well.
May 13, 2009, 04:25 PM
Registered User
Magic, I understand all your points and concerns.
I have an area of about 80'x80' in front of my cabin that I would like to fly in. Lots of trees but unlimited vertical! I have a couple of self made CD motors would probably work in a larger size. 32" sounds like a nice size, I'll wait and see what you come up with. Maybe it's time to spring for a bit of depron.
May 13, 2009, 05:52 PM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP

32.5" FFF version NOW AVAILABLE!


Hi miniman - ok, after getting home tonight (and before dinner, no less!), I scaled up the plans by 25%, which makes for a 32.5" wingspan plane. Plans for it are posted back in post #1. I figure that the AUW should be about 6.5 to 7 ounces for ideal "floatiness." But it's a full 3 square feet of wing area, as opposed to the 2 square feet of the 26" version - so it'll probably be okay up to 7.5 or even 8 ounces. That said, obviously: LIGHTER IS BETTER!

I've not made a version of this yet, so if someone wants to hack away at it and give a flight report sometime soon, please do!! Should be ideal for your 80' x 80' area, miniman. Let me know how it works for you.
May 13, 2009, 10:46 PM
If it flies I love it!
magic612, do you have un-tiled PDF versions of the plans? I'd like to make one of these on my PhlatPrinter, if you don't mind.
May 14, 2009, 04:43 AM
For us He died, in me He lives
Jimmy JFlyer's Avatar
Bravo! Magic612...Bravo.
Just what the Dr. ordered!
May 14, 2009, 07:55 AM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP
Quote:
Originally Posted by Dorsal
magic612, do you have un-tiled PDF versions of the plans? I'd like to make one of these on my PhlatPrinter, if you don't mind.
I do have untiled versions of both. I'll try to get both of them uploaded later this evening.
May 14, 2009, 10:20 AM
Registered User
Magic, before dinner? now your puttin the pressure on, let the hacking begin!!
I'll probably get started this weekend.
May 14, 2009, 11:59 AM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP
Well, in fairness, the scaling up part wasn't hard: Save new file, scale up using the "scale" button in AutoCAD, and adjust for different motor (had to add in where the 3/8" stick would go). That only took about 10-15 minutes.

What took longer was fixing all my mistakes AFTER that process!

"Oops - left some temporary dimensions on the main plan." Start PDF over
"Oops - didn't adjust the 3-view drawing to match parts." Start PDF over
"Oops - that paper line is between the wing support lines on the wing." Start PDF over

Once I got past all those dumb mistakes, it was just a matter of adding each "page" to the PDF file by appending it with each section. And I'll try and make one this weekend too, depending on how much time I have. (Gotta fix the concrete on the front porch.)

Oh yeah, and last night I designed a canard glider to work for an old GWS IPS geared motor I had laying around for which I got inspired to draw a plane, so there's that on the docket too. Nothing like trying to figure out how to make a 48" wingspan plane that will fly using a motor which only produces about 12-14 watts of power. Yay 3mm Depron!
May 15, 2009, 08:37 AM
Registered User

How about 6mm depron on the larger plane?


I have some 9gm servos, an e-flite park 300 brushless and 2s 15c 900mah batteries. What do you think? I just maidened my STC by waterdogg and it's time for another build. Thanks- looks like a great plane design.
May 15, 2009, 08:47 AM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP
Sidecar - I think the 6mm Depron would work just fine on the larger version. The only thing to be careful about is when bending the foam for the wings. Maybe it's just the Depron I've purchased, but in at the 6mm thickness, it seems to be more brittle and doesn't "give" as much. Just go slow and carefully, and it should be fine. The servos, motor and battery sound like just the right sizes.
May 15, 2009, 09:17 AM
Bernoulli+Newton=Lift
magic612's Avatar
Thread OP

Untiled plans


Quote:
Originally Posted by Dorsal
magic612, do you have un-tiled PDF versions of the plans? I'd like to make one of these on my PhlatPrinter, if you don't mind.
Dorsal - my apologies that I didn't get this done last night. Untiled versions of both plans are now available in post #1.

Enjoy!!
May 15, 2009, 10:42 AM
Registered User

Awesome, brother. Thanks for the quick reply.


I'm going to print the plans up right now.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Just got back from my first fly-in mcharles13 Electric Plane Talk 13 Jul 16, 2006 07:52 PM
Lawrence, Ks. Electric Outdoor Fly-In rreiss RC Flight Events 33 May 17, 2004 09:18 PM
Which plane can fly in the small cul de sac? csisfun Parkflyers 38 Apr 01, 2004 06:15 PM
trying to post my first ap,a gray day in my back yard steve ypsi mi Aerial Photography 6 Feb 20, 2004 09:16 PM
Kansas City Area Outdoor Fly-In (early May) rreiss RC Flight Events 9 May 12, 2002 08:11 PM