Notices
Scratch Building, Aircraft Design, 3D/CAD If you are starting/building a project from scratch or want to discuss design, CAD or even share 3D design images this is the place. Q&A's.

wing construction help

Old 02-13-2004, 02:46 AM
  #1  
Welshguytitch
Junior Member
Thread Starter
 
Welshguytitch's Avatar
 
Join Date: Jan 2004
Location: Kent, WA
Posts: 20
Likes: 0
Received 0 Likes on 0 Posts
Default wing construction help

ok... this plane i built a few nights ago in about 5 hours, not including covering... i dont have any plans... didnt follow any guidlines.. just kinda built it till it looked right... now i gotta build the wings.... i need help in designing them, or at least some advice on wingspan, width and whatever else... i want it to be like a miniture electric trainer.. with ailerons... but have no idea about wing loading all the technical stuff...

http://home.earthlink.net/~keremypaw/quickbuilt/ ignore the links, couldnt figure out how to delete them...

sorry bout the pic quality.. and my messy workspace!!

the plane is 30" long, tail is about 13" wide, goes from 3.5" at the tips to about 7" where it meets fusalage including rudder, vert fin is about 4.5"high...

all comments, advice, critisism welcome. after viewing the pics for a while i noticed that it lookes kinda warped ... especially the fusalage.... its all straight.... no warps... nothing... just the $30 ditital cam playin tricks on the pics...

Thanks all Paul
Old 02-13-2004, 03:15 AM
  #2  
BMatthews
 
BMatthews's Avatar
 
Join Date: Oct 2002
Location: Chilliwack, BC, CANADA
Posts: 12,425
Likes: 0
Received 22 Likes on 19 Posts
Default RE: wing construction help

Since you've already got the tail we have to work backwards. The rule of thumb is that the tail should be between 20 and 25% of the wing area for adequite stability. This is based on a "normal" fuselage. I make it as roughly 68 sq inches for your stab so the wing will be 4 to 5 times that area. That means your wing should be between 270 and 340 sq inches. Call it 300 sq inches for a nice round number Let's say the aspect ratio will be 5:1 to 6:1 which is right in the ball park for general sporty stunt models. The two wings that would come from that are 39(or 40) x 7.75 for 5:1 and 50x7 for 6:1. Or you can fudge it down more towards the 270 sq inch mark if you think these wings are too big. I wouldn't suggest it though. That fuselage looks fairly solid so you'll probably want the wing area to hold it up well.

FWIW I fly a 1/2A Texaco class old timer that has very close to 300 sq inches and at 19 oz it can still thermal just fine. That puts it at just a bit over 9 oz/sq ft. A sport model will fly very nicely at up to 11 or 12 oz/sq ft but for electric you really should try to keep the weight of a 300 sq inch model down to less than 20 oz. The lighter weight will let you fly longer and make the model more stuntable.

Best of luck with your new scratch building project.
Old 02-13-2004, 05:16 AM
  #3  
FHHuber
Banned
 
Join Date: Jan 2003
Location: gone,
Posts: 4,923
Likes: 0
Received 0 Likes on 0 Posts
Default RE: wing construction help

since you are playing... I would make the wing on the larger end of the appropriate range for the tail area... I'd use the 7.75 inch chord and the 50 inch span I'd place the wing ribs such that... if I thought the thing was to slow, I could just cut off a bay on each end to "liven it up". (about 2.5 inch between ribs... gives you 2 chop-offs leeway and you are down the the low aspect ratio wing of the 2 that Mr Mathews recommends )

More area... better slow flight. I would use 1/4 X 1/8 spruce for the upper and lower main spars... (overkill for a glider... probably right for the weight of the electric drive) 1/16 balsa to make the ribs. 1/4 square balsa to make the LE (put it corner to the front and just round off the corner... its easy) 1/4 X 3/16 TE "spar" and 1/4 X 1 1/4 taper trailing edge stock strip ailerons (these are part of the wing area) full span strip ailerons just cut em out to clear the fuselage... fill the gap with scrap as you rig the torque rods. (typical trainer style setup)

You can do a flat wing if you want. No dihedral joint to add weight. You do want to sheet the center of the wing with 1/16 to support the structure when ruber banding the wing on.

Your fuselage design demands either a flat bottom airfoil or you have to construct a wing saddle (which would if done right... look like a cockpit of a C-152.) if you want a symetrical airfoil.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.