Printable View
I need to know the correct spacing on the rib stitching on a kitfox lV wing, and the distance to place the first stitch from the leading edge of the wing. How for from the trailing edge has anyone stopped stitching. Any help is appreciated as I do not have this info in my build manual.
“Polyfiber Aircraft Coatings” How to Cover an Aircraft Using the Poly-fiber System,
This is the procedure manual for STC SA1008WE
If you don’t have this book, get one. $10 from ACS or you can get it from Kitfox LLC.
http://www.aircraftspruce.com/catalo...fiberCover.php
The chart for Vne Never Exceed shows the rib lacing spaced at 2-1/2 inches in the propwash area and 3-1/2 inches in the non-propwash area for aircraft under 170 mph. These are maximum distances. You can always go closer. Quite often the lacing is done at the same distance for the whole wing In this case 2-1/2 inches.
The first lace is always placed at half the required distance of the others. In this case 1-1/4 inch.
Lacing is continued until no greater than 2-1/2 inches from the trailing edge.
The same information is in AC43.13.
John Pitkin
Greenville, TX
My Model IV front rib laces are right behind the front spar. That is 3-3/4" from a carpenter's square with the leg up against the bottom of the rib.
To get each rib lace row to line up straight the full length of the wing a few of mine are spaced at 2-3/4". That was necessary to miss the drag tubes and brackets in a few places. At the rear spar the spacing is 3" and the last couple at the trailing edge are 2". All the rest are 2-1/2 inches.
It took a little time to lay it out but it was nice to be able to snap a chalk line the full length of the wing for each row and then not have to monkey around hitting structure inside the wing with some laces.
It looks nice too to see a straight line of laces on each row.
I just finished the final bit of rib lacing and can say that what is outlined above also applies to the SS. General spacing is 2 1/2". The front spar will not allow you to honor the 1 1/4" spacing for the first stitch. 3 3/4" from the leading edge gets as close as you can to the spar. 3" space for the rear spar. Also there are times when you have to be creative to get around obstructions. In the photo you can see where I couldn't get past the drag-anti drag tube. So I bracketed it with two stitches 3 1/2" apart.
http://tropicaltuba.com/Kitfox%20Project/images/319.jpg
Good luck! I doesn't take as much time as many think it does.
We had pretty much the same experience as Tom with one exception. We adjusted spacing for the spars putting stitches immediately in front and behind, but when we came upon other bits of internal structure, we basically bent the lacing needle so we could go around it while externally keeping normal spacing. Our stitches remained uniform, the laces were tight, but in a few cases did not go straight from top to bottom, but wrapped along one side of the braces. If I were to do it again, I would probably pay more attention to where the internal structure was and plan my spacing around it. What we did worked well, but was time consuming and was a pain in the rear. At times our needle looked like a big "C".