wing rib dimensions

[glembree]

With Leonard Milholland's plans, I received a "full size" pattern for the wing ribs.
Problem is that the length is 56-1/2" and I believe it is supposed to be 55".
So I adjusted the pattern to be 55", and I am cropping the height also so that it is 7-3/4".
I am wondering what experience others have had with the overall dimensions of the wing ribs.
And whether my dimensions sound okay.

[Kamcoman77]

Your adjustments are on the right track as long as your spar heights are built to correspond correctly with your rib. A very important dimension is 27.5" between the back of the front spar and the front of the rear. Remember that the rib should be 54" long. The 55" figure is after you add the 1" wide trailing edge. Almost everyone has had to make adjustments to the full size wing drawing from Leonard. Many builders have purchased a set of supplemental drawings from Iron Designs. They have a full size wing rib that copies a little cleaner.

[glembree]

Thank you !

[wapati-bull]

 my full sized rib drawing K46 doesn’t measure anything near 27.5 between the spars.

[Kamcoman77]

Very interesting! What is your distance between spars? I'm using the Iron Designs rib drawing. I'll see if I can find one of Leonard's.

[wapati-bull]

It is 28 3/16”. I have a hard copy directly from Leonard not a down loaded version.

[DA Miller]

My full size rib drawing from Leonard was also inaccurate as were many others who received them. Search "rib dimensions" and you will see many references to this.  Some people have had success with matching up the 8 1/2  x  11 sheets that came with the plans.  Others have had good success with the Iron Design drawings.  Since the Legal Eagles are slow (60 mph) there are many rib airfoils that work. The 27 1/2 dimension is important to get the wing attach fittings close to matching the fuselage attach points on the fuselage.  Top of the cabanes sta 2 and 3. The other important dimension is the length of the rib front to back as you are building the rib in your jig. One other gotcha: some builders found that the first vertical on the plans was not 90* with the bottom rib stringer.  Not much but when the rib was mated to the front spar it didn't match up. The good news is everyone finally worked it out.

[Kamcoman77]

I just measured my full-size Milholland drawing that came with the plans. It shows 28-1/16" between spars. Evidently, the Iron Design rib and the Milholland rib are not identical

[wapati-bull]

Well, actually station 2 and 3 are 29” on center so it would seem that 28 1/4” should put the spars close to 29”O/C. I am not familiar with any other drawings but my hard copy came with a one piece, full sized rib print.

[Kamcoman77]

Sounds like you are right on track. If you build your wing ribs and fittings to match your dimensions, everything should fit just fine.

[DA Miller]

My old set, and per the forum other older sets, came with several 8 1/2 x 11 sheets and no full siZed rib drawing.  I think I paid $15 for the full sized drawing whose dimensions did not match the plans spar dimensions. Don't forget to check the vertical of the first rib vertical. My advice is to study the plans upside down and sideways before cutting or gluing. People are fond of saying "all the required info is in the plans" but it's not always obvious. I would suggest that before you start on a new segment, you do a search on that segment.  Every possible mistake or misunderstanding has been done before and there is much good info and help from previous builders. Don't give up.  If you have a question just ask. we'
re all here to help

[DA Miller]

One more thing and then I'll shut up   Build your ribs first and then build your front and rear spars to match YOUR ribs

[wapati-bull]

I built the ribs first. Then the spars to fit the ribs. When make the nose ribs I plan
to have them match up to the spars.
But thanks for the input.

[scottiniowa]

My full size rib drawing from Leonard was also inaccurate as were many others who received them. Search "rib dimensions" and you will see many references to this.  Some people have had success with matching up the 8 1/2  x  11 sheets that came with the plans.  Others have had good success with the Iron Design drawings.  Since the Legal Eagles are slow (60 mph) there are many rib airfoils that work. The 27 1/2 dimension is important to get the wing attach fittings close to matching the fuselage attach points on the fuselage.    The good news is everyone finally worked it out.

DA Miller really nailed this, as they almost always work out.. but you have to stick to it., NO changing back and forth between rib layouts, no matter how minor.  At the speed of the aircraft, no one will be able to say this slight variation will fly better than the next unless you go into a "different profile completely" and I don't think this is the place for that kind of diversion.

The goal (in my opinion) is and always should be, to go into the build knowing exactly each step that will be coming next.. No head scratching, no "I hope this works" thoughts.  Thus the reason for my supplemental plans in the first place..  To that end, I think they have accomplished that goal, but many others have proved that a "stick to the plan, has worked rule"
Best of success to all!