Meet POKEY
#1
Senior Member
Thread Starter
Join Date: Apr 2002
Location: Sarasota, FL
Posts: 1,502
Likes: 0
Received 0 Likes
on
0 Posts

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.
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.
#2
Junior Member
My Feedback: (2)
Join Date: Apr 2004
Location: Poway,
CA
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts

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!
#3
Senior Member
Thread Starter
Join Date: Apr 2002
Location: Sarasota, FL
Posts: 1,502
Likes: 0
Received 0 Likes
on
0 Posts

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.
#7
Senior Member
Thread Starter
Join Date: Apr 2002
Location: Sarasota, FL
Posts: 1,502
Likes: 0
Received 0 Likes
on
0 Posts

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
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
#10

My Feedback: (20)
Join Date: Jun 2009
Location: LaGrange,
GA
Posts: 544
Likes: 0
Received 0 Likes
on
0 Posts

ORIGINAL: rsieminski
I need to figure out how to make canopies. ..
I need to figure out how to make canopies. ..

#12

My Feedback: (20)
Join Date: Jun 2009
Location: LaGrange,
GA
Posts: 544
Likes: 0
Received 0 Likes
on
0 Posts

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?
#13
Senior Member
Join Date: Dec 2002
Location: Lakewood,
NY
Posts: 795
Likes: 0
Received 0 Likes
on
0 Posts

ORIGINAL: PatrickCurry
Oh sorry, I got side tracked..... my question is about the 11% wing thickness.... 11% of chord? How do you calculate that?
Oh sorry, I got side tracked..... my question is about the 11% wing thickness.... 11% of chord? How do you calculate that?
Example; wing cord 10incnes + aileron 2inches = 12 inches X 11% = 1.32 inches, almost the exact size of a yard stick [8D]
Is there a minimum or is it just related to how fast you want to fly?
Jeff[8D]
#14

My Feedback: (20)
Join Date: Jun 2009
Location: LaGrange,
GA
Posts: 544
Likes: 0
Received 0 Likes
on
0 Posts

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!


#15
Senior Member
Join Date: Dec 2002
Location: Lakewood,
NY
Posts: 795
Likes: 0
Received 0 Likes
on
0 Posts

Patrick read this page from ChrisSpads web page.
Enjoy.
How to Design Your Own Spad
http://www.chrisspad.com/planes/main...paddesign.html
Jeff
Enjoy.
How to Design Your Own Spad
http://www.chrisspad.com/planes/main...paddesign.html
Jeff
#17

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