Rib Stitching Anyone??

[bbryan]

I am just about to the point of rib stitching which I'm sure I'm not going to be crazy about. Has anyone ever used Martian Clips on a KF?? Or do you think they will work. Any suggestions other than rib lacing will be great.

[Av8r3400]

There are hundreds, if not thousands, of Kitfoxes and Avids flying without any mechanical rib-to-fabric attachments. Only the poly-tac glue.

Neither of my planes are stitched, clipped or ...

[DanB]

Personally, I would prefer the path of "better safe than sorry". Granted you can do anything you want with your experimental build, however, the fact that the rib lacing is in the kit instructions is not an accident.

[Slyfox]

I know the way I fly. With that said, I did rib stitch. But, I got tired of the methode and went to individual loops all down the rib. Hope this helps, much easier doing it that way.

[Dave S]

Hi Bob,

Well....... if you have been around pilots and builders for very long, you are well aware that if you take all of us and line us up end to end it is nearly impossible to get two opinions the same....probably how it should be, cuz that is what keeps it interesting and keeps us learning. So..... I figure that gives me license to have an opinion of my own; while, everyone else out there can certainly have theirs.

My opinion is that wings, tail feathers, etc are going to be in service with however we build them for 20 years - given the type of materials we have now. That said, the time a person spends on rib stitching is almost irrelevant; and, doing it leaves no doubt about the outcome....I like the idea of having no doubt about the outcome in this business; but, that is just me.

Another angle a person could look at is this.....Building is a learning experience for each of us. Doing the rib stitching allows us to cross off one more little box on our bucket list - badge of honor for figuring it out or whatever. A new skill, etc. If a person doesn't learn how to ribstitch, a person is missing out on developing a skill which is so much a part of aviation history and airplane construction.

Actually, I was not looking forward to rib stitching either - sounded like a PITA - once I locked myself in the shop with the needle and thread and instruction book - turned out it really didn't take that long to complete the wings; and, I have to admit to feeling some degree of satisfaction having mastered the skill.

When it gets down to it, rib stitching is tried and true. There have been a few situations memorialized in the NTSB files where not rib stitching did not end well on experimental aircraft. I do not think any of them have involved Kitfox. Tried and true? NTSB files? Easy decision for me.

On the Martin Clips, looks like a good system for a metal ribbed aircraft - a person is going to have to decide if Martin clips will work in wood - you have the possibility of rot if the holes necessary for the clips are not well sealed; also, I would ask the Martin Clip People for technical assistance regarding if the thickness of the capstrips (1/8") would allow a good enough grip.

There is a litmus test - contact the person who will be your DAR see what she/he thinks.

Tried and true vs saving a few hours on construction? In the end it is the builders call. Each person has to live with his/her choices.

Sincerely,

Dave S
KF 7 Trigear
912ULS Warp

[hansedj]

It was not that hard to learn and did not seem to take too long to do. There is a video on eaa web site. We even put fake ones on the fuel tanks.

[Dorsal]

I agree with several of the above statements, thought it would be a real pita but once I started it it was no big deal. I feel good having done it, have no idea if it was really necessary.

[bbryan]

I must admit, the more I think about it the more I am swaying toward the rib stitching. Being a person that's only comfortable with over doing it. My initial reason is physical, being the ole back ain't what it use to be, but I am building this one as a keeper ( yea right) and maybe someday going electric once the technology gets there. The Martian Clip would require a rather large hole and may weaken the rib, but I'm still a thinkin. The wife says she will do it if I pay here enough.
Thanks for the super response.

[SaintAero]

I just finished the fabric phase of my project and rib stitched the wing ribs. It was not a big deal and actually went pretty fast. My stitches are about 3.25 inches apart. There are only 72 stitches total. Each rib required about 13' of string to avoid multiple starter stitches. No big deal -- Don

[Mark]

My wife actually did stitch our wings. It only cost me a couple of beers.

Rib stitching is easy and you'll be happier that you did. Also, there is an authentic look to stitched fabric that keeps the traditional feel. And as John McBean once said, "I have never looked out at my wing while flying and thought 'boy, I wish I HADN'T stitched my ribs"...

[jonbakerok]

You're certainly free to build your plane anyway you want, but I've got to say it -- the idea of "thousands" of planes flying around with the fabric simply glued the ribs sends a shiver down my spine. I've heard that the manual in the early kits didn't specify rib stitching but I had no idea that so many people actually skipped it. In the future I'll be inspecting the wing of any Kitfox I ride in!

I took the Polyfiber course last Spring and when the instructor showed us that weird knot, I thought I'd never be able to do it. But then after a few false starts, I was doing it. She gave us an hour to rib stitch two DC-3 stab's and I probably did four ribs myself in that much time. It just wasn't a big deal. It's really hard for me to imagine that someone with the patience to spend years building their own plane would skip attaching the fabric to the wings just to save a few hours work.

I'm no aeronatical engineer, but even I can figure this out -- without the fabric attached to the ribs, the airfoil becomes a simple elliptical arc, with the center of lift about a foot aft of the CG. I seriously doubt that you could fly that airfoil to a survivable crash. And if both wings didn't miraculously come unstuck simultaneously you'd enter an unrecoverable spin, anyway.

My wings will definately be rib-stitched, using the FAA-approved method, and I hope I've convinced anyone else reading this to do the same. This isn't a good place to be "experimental".

[jrevens]

Just a couple of thoughts from a new guy... first, by rib stitching, the load imposed by lift generated by the upper surface fabric doesn't have to be carried by just the capstrip on the upper surface of the rib. Some of it is also transfered to the bottom of the rib by the stitching - the assembly acts more like a solid structure, safer & stronger. Also, I believe that it was un-stitched wing fabric coming un-stuck that was a huge factor in the death of Steve Whitman. Just a beginner's humble opinion.

John Evens, Thorp T-18 (N71JE) builder/owner, & soon to be Series 7 S.S. builder.

[bbryan]

Don't mean to beat a dead horse but; if I elect not to do the rib stitching I understand pop rivets with the bigger head can be used. If I go this route would I stagger them on each side of the ribs at 3" or on both sides every 3" inches. Know anyone ever doing this. Would this weaken the ribs?
ALL INPUTS ARE WELCOME

[Av8r3400]

One man's opinion: I'm not a fan of drilling holes in the cap strips of the ribs. You would also have to put a washer or some type of backer on each rivet to hold it from pulling through. That sounds like a real bear to me.

[n85ae]

Rib Stitching is a very satisfying part of fabric aircraft building, I can't
imagine why so much energy devoted to discussion. I found it to be a
rather pleasant winter weekend project when I built mine.

Of course maybe I was so high from MEK fukes I just thought it was fun ...

Regards,
Jeff Hays

[t j]

Rib lacing a kitfox is not a difficult job and I agree it is the most fun part of building. It does not take long and is a good chance to involve the significant other or the kids. Build a wing rib lacing rack and get a friend to pass the needle back and forth.

Take 5 minutes to see it done.

Sein Knot
http://link.brightcove.com/services/player/bcpid1431564069?bclid=1432781694&bctid=22430488001

Finish knot
http://link.brightcove.com/services/player/bcpid1431564069?bclid=1432781694&bctid=23753223001

[Dave S]

Bob,

If a person is trying to decide this one - rather than me expressing my opinions, there is another way to think about it. After all, I have only built one airplane - I might not be that much of an expert.

1) If you are involved with an EAA chapter, the chapters have technical counselors who are really useful - see what they/he/she say. These folks want you to succeed and will advise accordingly.

2) There is a litmus test - contact the person who will be your DAR - see what she/he thinks. The DAR will be inspecting your airplane down the road and will sign off on an airplane certification they are convinced will not tarnish their record. Your DAR has a knowledge base on these matters and also wants you to succeed.

Happy new year,

Dave S
St Paul, MN

[Ken Birchard]

I just finished ribstitching my wings about a month ago. Once you get the hang of it, its just repitition. As a first time builder I'm tryinhg to not cut any corners and feel it was well worth the time for the extra fabric support.

[bbryan]

OK, I convinced. Rib stitching it is. Thanks for everyone's input on this. The more I thought about it, the more I realized the correct answer. And it may pan out to be a fun experience with enough fumes. "Close the windows and bring the glue, Honey were going to rib stitch". I'll let ya know how it went this spring when I can open the windows and get some fresh air.

[DesertFox4]

I believe the manufacturer of the kit recommends rib stitching. That's enough for me. At the speeds we can now attain with Kitfox's it would be reasonable and prudent to follow the recommendation of the folks that sell the kits.