Thread Tools
Aug 11, 2020, 07:55 AM
Registered User
Thread OP
Discussion

To anyone who has plans that show a flat bottom wing rib


To any of you who have plans for any plane that has a flat bottom wing. I need a copy of the wing rib from your plans. Size doesn't matter, but it must be a rib from a flat bottom wing. I use them to make templates to cut foam wings. I will gladly pay someone to send me one. Thanks.
Sign up now
to remove ads between posts
Aug 11, 2020, 08:30 AM
An itch?. Scratch build.
eflightray's Avatar
If you want an airfoil that is flat all the way across the bottom, (you just want to cut the top ?), you might as well just draw a curve that you like the look of.

if you want to do 'proper' named airfoils, (Clarke Y is a good basic one), then download some plotting software. This one is free, and I use it -- Profile 2.2 picture below.

There are plenty of sites that list the airfoil coordinates for all sorts of airfoils. e.g. -- UIUC Airfoil Coordinates Database It will allow you to make some better quality wings sections. Flat bottom sections have limits, that's why there are so many named airfoils out there.

Picture below is a screen shot of the plotter. It is capable of scaling, percentage thickness, and showing sheeting thickness if that is what you intend to clad the foam in.

.
Aug 11, 2020, 08:33 AM
An itch?. Scratch build.
eflightray's Avatar

Foam wing ?


P.S. I hope the 'balsa bashers' don't put out a contract on you.

Aug 11, 2020, 08:44 AM
Registered User
perttime's Avatar
Here's ribs copied from Mark Rittinger's "Python" (small kind of P-51 model).
For 29" span, 1/8" washout suggested for each wing.
Aug 11, 2020, 09:48 AM
B for Bruce
BMatthews's Avatar
Outerzone has oodles of plans with flat bottom wings. Download theone you want and open the file. Use the "select" tool to highlight the airfoil and copy. Then open up an image editing program and paste. Adjust size and print.
Aug 11, 2020, 10:31 AM
Registered User
Thread OP
eflightray and BMatthews, there are probably some flat bottom wings in these plans, but short of knowing which ones have flat bottom wings ahead of time, I would have to click on each plan until I found one. And the plotting thing would be way too complicated for me to use. I was kind of hoping someone in here already had a set of plans for a flat bottom wing plane and they could just send me a copy of the rib. The copy of the top rib in the file posted by perttime MIGHT work, but I'm looking for a wing chord that's a bit thicker...this one isn't quite thick enough, though it does have a flat bottom...
Aug 11, 2020, 11:57 AM
'Douglas' to his friends.
Here's a few; it's worth clicking through a few OZ plans, though, as you'll find something pretty quickly that fills your needs. Still, here's my Goldberg Electra, Short Skyvan and Goldberg Mirage plans, with flat-bottom ribs. Hope this helps...
Aug 11, 2020, 12:16 PM
AndyKunz's Avatar
Quote:
Originally Posted by grampi2
eflightray and BMatthews, there are probably some flat bottom wings in these plans, but short of knowing which ones have flat bottom wings ahead of time, I would have to click on each plan until I found one. And the plotting thing would be way too complicated for me to use. I was kind of hoping someone in here already had a set of plans for a flat bottom wing plane and they could just send me a copy of the rib. The copy of the top rib in the file posted by perttime MIGHT work, but I'm looking for a wing chord that's a bit thicker...this one isn't quite thick enough, though it does have a flat bottom...
It would certainly help if you could give a bit more information on what you're looking for, and perhaps why. Some of the guys here are pretty well versed on aerodynamics as well.

Andy
Aug 11, 2020, 01:06 PM
Registered User
perttime's Avatar
Quote:
Originally Posted by grampi2
... The copy of the top rib in the file posted by perttime MIGHT work, but I'm looking for a wing chord that's a bit thicker...this one isn't quite thick enough, though it does have a flat bottom...
The top one is the wing outline, copied from the fuselage side, with leading edge and 1.5mm (or 1/16") sheeting added.

I have it in a vector graphics format, so size and proportions can be edited with ease. Just don't ask me anything about aerodynamics....
Aug 11, 2020, 04:24 PM
Registered User
Thread OP
Quote:
Originally Posted by AndyKunz
It would certainly help if you could give a bit more information on what you're looking for, and perhaps why. Some of the guys here are pretty well versed on aerodynamics as well.

Andy
I don't know if I can explain what I need. I will be cutting my own wing from Styrofoam. I need to make hard wood templates of the airfoil shape to place on the ends of the wing for the hot wire foam cutter. I just need an airfoil where the shape of the airfoil on the top of the wing is conducive to use with a flat bottom wing. I want the bottom of the wing flat so it doesn't have to be cut. In other words, the cut would start at the bottom of the leading edge, and then go over the top all the way back to the trailing edge, and that would be the only cut. Adding another cut on the bottom of the wing makes the process too complicated. I'm not certain about this, but I don't think the airfoil has to be of a specific shape. I think as long as the thickest part of the chord is roughly 1/3 of the way back from the leading edge, just about any shape would work. In fact, I could probably make up mu own shape that would work, I would just rather have a copy of one from a plan, at least that way I KNOW it's from a plane that flies...
Aug 11, 2020, 04:25 PM
Registered User
Quote:
Originally Posted by grampi2
To any of you who have plans for any plane that has a flat bottom wing. I need a copy of the wing rib from your plans. Size doesn't matter, but it must be a rib from a flat bottom wing. I use them to make templates to cut foam wings. I will gladly pay someone to send me one. Thanks.
Here is one from the 1960s, the Lil Spirit.. https://outerzone.co.uk/plan_details.asp?ID=6484
Aug 11, 2020, 06:20 PM
'Douglas' to his friends.
Quote:
Originally Posted by grampi2
...I would just rather have a copy of one from a plan...
Are none of the three I posted suitable..?
Aug 12, 2020, 04:30 AM
Bellanca Kruesair
epoxyearl's Avatar
Not being able to convey the length of chord, and the thickness, is making it nearly impossible for us to help. I have plywood templates for foam cutting a 15" chord length (overall) of the Piper Cub 'Clark "Y" ' AND the USA 35-B for the same airplane. (slight undercamber).

We can only assume that's what you don't want also....
Latest blog entry: Ban Birds.
Aug 12, 2020, 06:10 AM
Registered User
Kadet SR perhaps. Found on aerofred.com. Iím building my first foamy myself, profile plane as a beginning.
Aug 12, 2020, 08:34 AM
An itch?. Scratch build.
eflightray's Avatar
There are plenty of models in the --- Foamies (Scratchbuilt) forum --- that have wings with a flat top and flat bottom, i.e. just flat sheet, just add a slight radius on the leading edge. Most fly extremely well, so don't worry too much about the airfoil shape unless it's the looks that are important.

Your EPS foam wing will quite likely still need some kind of strengthening, spar, skinning, etc, as EPS is not very strong on its own.

Also in the above linked forum, check out the - Kline-Fogleman (KFm) Airfoils...... - thread at the top, (a 'Sticky' thread), it has some alternative airfoil shapes and methods. The 'naysayers' criticize the KFms as inefficient, may be so compared to an accurately cut named airfoil, but for some reason there are loads of models flying quite well with them.

.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Who has the Best Foam-Sandwich Wing Plans? Orangejoe 3D Foamies 7 Jul 13, 2017 08:46 PM
Discussion Flat bottom wings and power plants stsguy Flying Wings 4 Oct 17, 2015 01:52 PM
Discussion Who Says Flat Bottom Wings Aren't Any Good ? Chophop Electric Plane Talk 18 Sep 13, 2012 05:16 AM
Discussion Flat bottom / under cambered hybrid wing, anyone? signflyer Foamies (Scratchbuilt) 2 Mar 12, 2012 03:12 PM
Discussion Looking for a EPP Bipe Plans with a wing that has ribs Like a "UZI" XXL eng30 Foamies (Scratchbuilt) 6 Dec 12, 2010 01:10 PM