Full Scale Plans

Full Scale Plans

(Click here to download the full scale plans - 27.2Mb)

NOTE: Although these are 'full-scale' plans, the actual scale of the plans when printed out varies by +/- a percent or so from drawing to drawing. It is very important to check the *actual* scale of each drawing and mark this on each sheet. You will need to use extreme caution when working from these drawings to ensure that you build each part to the correct dimensions - Do NOT trust the scale of these drawings! That said... these are the drawings I am working from. I got them printed out through my brother's engineering company which regularly prints out large drawings. The drawings are roughly 4' x 2' each in size.

To work out the actual scale of each drawing find the largest indicated dimension on the drawing (the larger the part you are measuring, the smaller your error will be):

Actual Scale = Physical Measurement of the Drawing / Dimension Indicated on the Drawing x 100

So, if you measure a part on the drawing using a ruler at 15.1" and the drawing states that the full scale dimension is 60" then the Actual Scale of the drawing is 15.1 / 60 x 100 = 25.17%

Scale Factor = Dimension Indicated on the Drawing / Physical Measurement of the Drawing

Using the same measurement and dimension off the drawing, the Scale Factor = 60 / 15.1 = 3.97x

Check the Actual Scale and Scale Factor in both the X and Y dimensions on every drawing and apply the Scale Factor to all measurments you take off the drawings for every part.

Errors in the Plans

Builder's Manual

Builder's Manual (Original & Electronic)

(Click here to download an archive of both versions of the Builder's Manual)

The original Builder's Manual is included (along with an electronic MS-Word document version) because, in places, the plans refer to specific pages in the original Builder's Manual. The Word document version, while more useful and searchable, has lost the pagination of the original, making the references on the drawings difficult to follow.

Phil's Wing Stress Analysis

Analysing the Loads and Stresses Along the Wing

My wing calculations are based on the formulae and method described in Jim Marske's Composite Design Manual. If you don't yet have a copy of this manual then I strongly recommend that you buy a copy, even if you don't intend to do the calculations yourself for your own design loads - it contains a large amount of practical knowledge about working with and fabricating composites. The photos, below, are of my initial hand written calculations, refrencing the appropriate pages in Jim Marske's manual, and show the formula and description of the method used to arrive at the numbers in my spreadsheet.

Download my spreadsheet here - it summarises all the calculations below and allows you to enter your own initial design loads to see what effect they have on the various parts of the wing.

I designed my Carbon Dragon to my own specific load criteria. I take absolutely no responsibility or accept any liability whatsoever for any adverse consequences should you build your own Carbon Dragon to the same design configuration as detailed in my calculations or for using my spreadsheet and any design numbers that you may obtain from it by modfying the initial circumstances. You use my calculations and spreadsheet entirely at your own risk.

Click here to download an archive of Phil Lardner's wing load/stress analysis

Aerodynamic Analysis

AERODYNAMIC ANALYSIS OF THE CARBON DRAGON AIRFOILS

 (Click here to view the original webpage of this article)

PART ONE

About the author:

Alejandro Ramirez-Pineiro (30) has the degree of Bachelor of Science in Mechanical Engineering, earned at the Universidad Tecnologica Metropolitana of Santiago, Chile. At this moments he is working as a Composite Materials Engineer at ENAER, building a 100% composite JAR 23 airplane (visit www.euro-enaer.com ). Also he is building a modified Carbon Dragon, planned to fly during the first quarter of 2000. You can reach him at This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. .

Introduction:

The Carbon Dragon is an ultralight, high performance glider.  This glider was conceived by Jim Maupin who also designed the famous Woodstock sailplane and the Windrose motorglider.  With encouragement from Irv Culver, who promised to "run the numbers", Jim Maupin finished the design and built the prototype.  As a result, Jim Maupin with an assist from co-designer Irv Culver, produced an exciting sailplane.

Scope of the study:

The proposal of this study is getting aerodynamic data that can be used for the structural modifications of the original Carbon Dragon. This data will be used also on the study of the longitudinal static stability of the modified glider. All the aerodynamic values presented here can be useful to actual or future builders for helping their own studies.

For preliminary design, the values presented in this report are excelent, but must to keep in mind that the data presented here was developed by a computer software, so, to get more “real” values, the reader will have to do wind tunnel testing.

Getting the coordinates:

To get the coordinates of the wing root and wing tip airfoils, the original drawings of the ribs number 1 and number 13 where divided on 88 stations on the root and 58 stations on the tip. The mesures where taken with an accuracy of + - 0.5 mm. The job was done by my building partner Miguel Eyquem.

With the coordinates obtained in milimiters, the next step was to convert them in fractions of chord. For this task I used an electronic spreadsheet.

Airfoil Coordinates of the Wing Root Airfoil

(values on fraction of chord)

Image 1. Carbon Dragon Wing Root Airfoil

Airfoil Coordinates of the Wing Tip Airfoil

(values on fraction of chord)

Image 2. Carbon Dragon Wing Tip Airfoil.

Using the software:

The software used was Airfoil Analysis Geometric Module (to get more information and/or demos visit http://airfanalysis.hypermart.net ) developed by two Engineers at Italy.

The data was imported from a text file into the Coorditate Editor to make easier the data imput to the software.

Using both airfoils (root and tip) was possible to get by interpolation the mean geometric chord airfoil, slightly different from the Mean Aerodynamic Chord, for a simply, linearly tapered wing. For this task I used the Airfoil Mix Window and set the mix proportion to 50 %. See the Mean Geometric Chord coordinates table.

With the coordinates of the root, tip and Mean Geometric Chord airfoils the software was able to give the following information:

1 - Geometric data of the airfoils

2 - Estimated aerodynamic data, including:

• Angle of atack for zero lift, a 0
• Pitching moment at zero lift, Cm0
• Lift slope, a0

Airfoil Coordinates of the Wing Mean Geometric Chord Airfoil

(values on fraction of chord)

Image 3. Carbon Dragon Mean Geometric Chord.

Geometric Data of the Carbon Dragon Airfoils

Estimated Aerodynamic Data of the Carbon Dragon Airfoils

Observations regarding the geometric characteristics of the airfoils:

a) The increasing camber toward the tip should be due to a research of higher maximum lift coefficients to avoid tip stalling.

b) Progressively moving forward the maximum center position should be due to obtain earlier transition on the tip section and minimize Reynolds number effects.

c) The increase of the L.E. radius help to soften tip stall.

For the eager builder/designer:

Some remarks about the “estimated” aerodynamic data presented in AIRFOIL ANALYSIS – GEOMETRIC MODULE: The estimates of zero lift angle and zero lift quarter chord moment coefficient are obtained by the Pankurst’s method (“Theory of Wing Sections”, by Abbott and von Doenhoff) … relying just upon the knowledge of the mean line shape: it’s a sort of Gaussian quadrature and it should had been developed analytically, so no numeric is still present at this stage. The method is surprisingly good, relating to its simplicity, as you own will experience when comparing estimated to calculated data (by the numerical panel method or comparison with experiments). In fact, the flow quality on the airfoil surfaces is still “good” in the proximity of the zero lift angle (that is usually small) for conventional, unflapped airfoils … this explains why these estimates are incredibly useful even if absolutely “a priori” of any aerodynamic analysis as properly defined.

The lift curve slope efficiency factor m (the ratio of the potential flow slope to the theoretical value of 2p) is estimated according to R. Eppler (“Airfoil Design and Data”, Springer Verlag) but it’s usefulness is usually driven off by viscous effects … so practically it doesn’t matter anymore when viscous analysis are on hand.

References:

Airfoil Analysis – Geometric Module

http://airfanalysis.hypermart.net

Engineer Luca Cistriani

http://airfanalysis.hypermart.net

Carbon Dragon Technical Website - by S. Steve Adkins

http://www.isd.net/sadkins/builders.htm

Jim Maupin Ltd.

www.jcpress.com/JMaupinLtd/carbon.htm

The part II of this study will include:

• Presure distibution
• Velocity distribution
• Cl/Cd polars
• Cm/a polars
• Lift slope

Notes & Modifications

Contest!

Contest for the Purchase of the Last Plans Set

[Revised 7/12/2004]

A contest is being conducted to see who bought the last set of plans from the Maupins; and thus, has the highest serial number.  The prize is publishing your number and a link.  Thanks to Steve for not only sending in his serial number, but sending a photo of his plans canister with the serial number.  Due to some kind of mix up on my part, I used Steve's letter but attributed it to another builder.

Please be aware this is the fourth "Steve" involved with the Carbon Dragon:
 

 
Please include Name, address, email, Serial Number and Intentions to build, study or modify.
 

Update from Winner - Steve Rappe with Serial No. 476

Subject: plans number 476  Steve Rappe of Ft. Mill S.C.  This email address is being protected from spambots. You need JavaScript enabled to view it.   Steve writes ......    Hi Steve,  I was just examining your new Carbon Dragon page and noticed you updated the plans sold to number 473.  I can only imagine you are serious about the number sold.  ... snip ... Anyway here is a photo of my canister.     I'm still working on building space but have a hope to build the Cd or a derivative.