rsieminski

About 12hrs in the Temporary Hobby Room, minus bathroom breaks, lunch, dinner, and a snack, futzing with a broken servo, and out comes POKEY:
48 x 11.75 Polyhedral wing, 5" Dihedral each 12" side, 33" coro 5 sided box fuse, ASP .21 on the nose, AUW 3lbs, 4oz.





I need to figure out how to make canopies. I hope the ASP .21 is enough. The wing is 11% thickness, and the spar is at 30%. I stole the dims from a simple dihedral wing that I had in the garage, but was all beat up. I remember keeping it because it flew really great (I think, maybe I just forgot to throw it away). I measured the dihedral at 10", so that's how I got 5" per side. I've never built anything with polyhedral, so I'll let you know how the maiden goes when I get a chance. The wing kinda looks like a Slow Poke, so therefore POKEY. Do you calculate wing loading by footprint, or by actual total SA? Footprint wise, I have 17.3oz/ft2. SA wise I have 13.3oz/ft2. I used 2 servos for the elevator, one per half, and I mixed some twist coupled with the rudder, via a switch just in case it was a really bad idea. I don't even know what you'd call those now? Ailerators? Initially I was going to use just 1, but they seemed too small for the SA, so I used 2, and then I thought about the mixing... maybe it'll help the barrel rolls? It took about an hr to figure out the mix, it just would not do it... Until I figured out one of the brand new servos would not move no matter what.

SemperFitz

My Feedback: (2)

Wow great plane and build. She looks pretty and like she'll fly straight. Let us know how it goes, I'm curious how the polyhedral works out, I imagine it'll be wicked stable. For your wing loading question (and math guys, correct me if I'm wrong) you will get 100% lift from the center section and then the outboard area of the wing will give you slightly less lift due to the angle. You could probably do some complicated trigonometry to figure out the exact area/loading, but that would kinda take the fun out of it. Fire her up and see what happens! Good luck!

rsieminski

You could fly her in a little league baseball field. Nice and gentle on low rates, and on high rates will nearly bite her own tail, and do violent snaps, where she'll almost stop in the air. She glides for a long time without power, was not prepared for that. I run a MAS 10x4, and vertical is unlimited. A real joy to fly. So comfortable, I mostly fly below 25 ft. I'm still breaking in the engine, so I did loop after loop, maybe 10 in a row, and she stayed right in the same place.

BIG4D

That is GREAT! What is it made out of? I mean what are the materials? IS the fuse the same materials as the wing?...

rsieminski

Yep, all coroplast

SPADinfluence

My Feedback: (1)

Sweet! Plans?

rsieminski

SPADinfluence ,
I'm flattered that you'd like plans. Wow, cool. I didn't make any, I just kinda winged it. I have the main dims in the 1st post. If you need any other instruction, I'd be glad to help, give more specifics, etc. Feel free to email me.
Thanks,
Rick

PatrickCurry

My Feedback: (20)

Yeah, that is super nice R!  I'm on my first spad right now.... I'm building a Debonair.  The Pokey is awesome though! 

rsieminski

The Deb, is one of the best trainers out there, no matter what their built out of. Welcome to the addiction!

PatrickCurry

My Feedback: (20)

Hey R, go to Walmart and find something you need in one of those blown plastic packages with ribs down the side.... you know the ones that you slide the knife down the side and half hack yourself up and they're hoping you don't return? Look around and find something that's round or with a shape that you can cut a canopy out of. Either that or wander around in the grocery section looking for a bottle the right shape and size. Cut a template and carry it with you to hold up to the bottle. People might think you're weird but that's never stopped us before.

PatrickCurry

My Feedback: (20)

You think this would work as a high wing and what would be the difference in flying characteristics?  I'm not real swuft on aerodynamics.  [&:]

PatrickCurry

My Feedback: (20)

Oh sorry, I got side tracked..... my question is about the 11% wing thickness.... 11% of chord?  How do you calculate that?  Is there a minimum or is it just related to how fast you want to fly?

MrGreenSpeed

Measure the wing cord + the ailerons and multiply by 11%

Example; wing cord 10incnes + aileron 2inches = 12 inches X 11% = 1.32 inches, almost the exact size of a yard stick [8D]

Hard to say as there are so many variables with wing design, and yes a fast wing would use a lower % of the cord.

Jeff[8D]

PatrickCurry

My Feedback: (20)

Is 11% a standard?  I mean what determines the thickness?  Why not 8% or 15%?  Sorry, I don't know how to ask what I want to know.    If I want to make just a regular ol' spad wing with the chord the same all the way out, how do I know how thick to make it?  Do I stick with 11% as I size my wings or do I use a different number?  I want to play around with that Basic Model Airplane Calculator to design planes (pretty much just plane ol' trainers and such) and it gives recommendations on sizing everything except for the thickness of the wing.  I'm just trying to figure that part out.  Pardon my ignorance.    Thanks Jeff!

MrGreenSpeed

Patrick read this page from ChrisSpads web page.
Enjoy.

How to Design Your Own Spad

http://www.chrisspad.com/planes/main...paddesign.html

Jeff

PatrickCurry

My Feedback: (20)

Thanks for that link Jeff!  That's just what I need.  That makes things a lot clearer for me.

Clean

I generally just TLAR it and if something doesn't quite work out right I work on that aspect.

There is one problem with that. Some peoples TLAR just don't TLAR!

Not Mine!

PatrickCurry

My Feedback: (20)

That's my problem Clean, I gotta know what it looks like before I can TLAR it!  LOL