Studying the Plan

[dz1sfb]

Well I received my plans on March 14, 2016.
My background as a Metal Model Maker, and a Model Airplane Designer and Kit Manufacturer, has taught me to study the drawings carefully and read everything, more than once. Don't miss any notes.

That also can give me grief! Listening to Sam Buchanan's EAA Webinar on the Legal Eagle confirmed my condition. The simplicity of the plans means there are not too many hard fast dimensions. Just be consistent! That can be a problem as Sam mentioned for the guy who is used to working to thousandths of an inch (hundredths of a millimeter). I am used to and more comfortable working in more concrete numbers and detailed drawings. However, this makes the project more interesting for me and I will make up some CAD sheets to complement the originals for my use.

A big thank you to scottiniowa for his CAD work. I am utilizing his services in this project as well.

This next month of April will find me somewhat sidelined from starting any physical building, but I will be studying the drawings and seeking answers to the questions inherent to the plans.

I will try to find answers initially by combing through the site, and have already revived one thread on tail surfaces that seemed incorrectly answered to me.

[Tom XL-7]

Everything you need  is in those drawings. Just enjoy the journey.  You really don't want measurements like 5 and 63/64ths inches. 
I will not weld or drill anything on my fuselage regarding tailfeathers until same feathers are built. Then I will make it work. Yes I will do my best but I would rather mount them than change them. Everypart we make is pretty much handbuilt without jigs except the ones we one off jig. My ribs will be different than your ribs and on and on. It's OK. It is just the way it will be.
PS hint from old site I believe John Bolding. Only put one wing mount on the fuselage(front) until your wings are done.
Tom XL-7

[dz1sfb]

Thanks for the encouragement Tom!

The process for construction of this project allows for variation. Just keep the steps in order to not build yourself into a box. This holds true even for more precision work. You always have to allow for variation. It is all about controlling what is important and making allowances for everything in between.

[dz1sfb]

I continue to study the plans until it all seems clear. I taped up the sections of full size wing ribs and found that they don't match very well. Some overlap, others are not able to touch. Notably on the nose rib sheet there is a scale shown on there and there is .050" growth per inch on the sheet, plus the distance measurements are illegible. I would love to put together a good set of tiled sheets that Leonard could have in his plans sets. This is really important to start with correct at the beginning.

Does anyone have some distance numbers for the full size airfoil?

[joecnc2006]

I continue to study the plans until it all seems clear. I taped up the sections of full size wing ribs and found that they don't match very well. Some overlap, others are not able to touch. Notably on the nose rib sheet there is a scale shown on there and there is .050" growth per inch on the sheet, plus the distance measurements are illegible. I would love to put together a good set of tiled sheets that Leonard could have in his plans sets. This is really important to start with correct at the beginning.

Does anyone have some distance numbers for the full size airfoil?

I would suggest you get a full size sheet from Leonard or do what I did was buy the plan sheet set from Scott "Iron Design L.L.C." he has some good sheets/supplemental's from the high school project.

[Vince Carucci]

You're right, the pages for the ribs don't fit perfectly end to end. But if you take the time to make sure the drawings line up again over the gaps and overlaps, you will create a template that is the correct size. Mine was less than 1/8 in under 55 inches when finished. 

If you photo copy the drawing received from Leonard, make sure the copies are correct. This forum has suggested drawing a scale in pencil on the originals and then measuring that scale on the copies to verify size. 

A teacher once told me that when making a table, it doesn't matter if the length of the legs are correct, just make sure they are all the same. 
It's kind of the same thing with the ribs. 


Good luck.

Vince

[Tom XL-7]

The sheets will go together. Many here have done so. Run your drawings through a copier. Save the originals-always.
The pages don't go edge to edge. not even ink to ink.  Try an overlapping layout matching the given lengths The  bottom will be a flat line. There is a lot of white paper that needs to be cut off. Still you will overlap. Go  for a fair curve on top, keep the bottom as a line. Ignore the diagonals. they go between the vertical sticks.
No head scratching required.
 I got it to work, made a jig and then drew one from scratch. I was amazed at how well the two matched. Good enough that I will not remake the jig.
 The airfoil data is on the old site but I believe  Dan posted it here at one time.
It doesn't take long to draw one . You will need a piece of paper 54 " long plus. I used the back side of two 24 x 36 architectural drawings taped together.
You make a straight line 54" long. (chord line), Mark the stations along same, then with a square mark the upper and lower values. The bottom is easy. the top will require you to generate a fair curve.
I will see if I can find this data in a form I can copy and send . Mine are in excell and are not cooperating.
Tom XL-7

[Tom XL-7]

Notice my chord is 54 inches and others is 55. Makes for a good question. Leonard calls out 55 on the first page of the plans in the specs.
My jig is 54 with a blunt trailing edge. I guess it will be 55 when I add the tapered trailing edge piece. 3/8 x 1' taper.
But that might explain the slight misfit of the hand drawn from coordinates paper to my jig. The values use 54 inch chord round nose to pointy trailing edge.
Tom XL-7

[dz1sfb]

I would suggest you get a full size sheet from Leonard or do what I did was buy the plan sheet set from Scott "Iron Design L.L.C." he has some good sheets/supplemental's from the high school project.

I am planning on getting the sheet from Scott. His work is more than worth the money. No gripes here. 

I know I can interpolate the sheets together and get fairly close. The part that bothers me most is the oversize to what appears to be the scale  on the nose rib sheet. This is giving me no confidence in it, and the non readable dimension line below the rib that calls out the space between spars and distance to the trailing edge. I really like those reference dimensions when it comes to taping a tiled drawing.

[dz1sfb]

The sheets will go together. ...  The airfoil data is on the old site but I believe Dan posted it here at one time. It doesn't take long to draw one . You will need a piece of paper 54 " long plus. I used the back side of two 24 x 36 architectural drawings taped together. You make a straight line 54" long. (chord line), Mark the stations along same, then with a square mark the upper and lower values. The bottom is easy. the top will require you to generate a fair curve. I will see if I can find this data in a form I can copy and send . Mine are in excell and are not cooperating. Tom XL-7

[size=undefined]That would be awesome Tom!

Thank you. I will do some digging for it also.
[/size]

[Tom XL-7]

The missing values are 27.5 between spars  and from front of rear spar 18.75 to end (blunt end not point)
the nose rib is another one of those things that are best made after the ribs and front spar.  nothing else matters more than that they fit.
aileron rib ends-ply, I made my pattern then spliced an extension on it
try to not get too far ahead as you build.
use the actual airplane as your jig-as in landing gear- wouldn't be hard to be off on that -just a hair is too much.

don't know if attachment works

[Tom XL-7]

The attachment appears to work 
I hand drew the 2nd chart , It is 54 overall and I think you should draw the first chart. The 55" NACA 4412
In the spread sheet the charts are the same if you change the value of chord length to match.
I did not say the legal eagle rib is  NACA 4412 but this information from the old site suggests it. I also have a clark Y airfoil  that has been put up as well.
Next go round for me will be to draw the NACA 4412 and snip the point off the trailing edge and see how that sits in my jig.
Tom XL-7

[dz1sfb]

Tom,
Excellent information!

[Dan_]

The attachment appears to work
I hand drew the 2nd chart , It is 54 overall and I think you should draw the first chart. The 55" NACA 4412
In the spread sheet the charts are the same if you change the value of chord length to match.
I did not say the legal eagle rib is  NACA 4412 but this information from the old site suggests it.  I also have a clark Y airfoil  that has been put up as well.
Next go round for me will be to draw the NACA 4412 and snip the point off the trailing edge and see how that sits in my jig.
Tom XL-7

Attached...

I'm gonna say the solid line is the Clark-Y...  

Not much difference, except where max thickness occurs and camber.  It does not take much in the way of these kind of details to make big differences over an area the size of a wing.  For example center of lift, pitching moment, etc.

[Tom XL-7]

So 
Does either represent the eagle rib.
Both have quite a history.
Appears both are close
we know the max height location on the eagle rib is where that tallest vertical lays.
tom xl-7