[Nick172]

I have my hs stab skin in the jigs. I am placing the HS-905 nose ribs in the skin to cleco them in place before drilling. I have to push hard and spread the skin apart somewhat to get them to line up with the holes. The instruction say to flute the nose ends, but how much? Do I need to do this? Is it okay to push hard and just cleco? Should I do something completely different?


Thank you,

 

[mikehoover]

Check out my log entry for work on the nose ribs at:

http://www.aclog.com/rv-9a/index.php?c=1#281

There are a couple of photos with this entry that may help. The second photo shows the fluted nose rib upclose. Just flute until they fit, but you likely will need to give a little push as well. Hope this helps.

Mike

 

[Lionclaw]

If you haven't already, deburring and straightening the tabs on the front of the ribs really helps them slide in better. Otherwise the sharp edges gouge at the inside of the skin and keep it from sliding easily.

 

[rv9av8tr]

HS nose ribs.... ick

I found those ribs don't fit worth beans and no amount of fluting made it better. When driving those rivets, the HS skin pulls in (top and bottom) slightly at those ribs. I think they are just too narrow.... or the skin pouchs "out" between the ribs, making it look sucked in at the rib.

 

[rrd1_99]

Yep, they don't fit right

I ended up making some shims out of .032", the width of the rib flange and length of the forward portion of the rib. I only used these on the center nose ribs (one each side). And yes, make sure you deburr them really well.

I think maybe Van's did this on purpose to give builders something "imperfect" early on in the project so they get used to it.

Roger Barnes
-9A slow QB
La Grande Oregon

 

[mr scout]

I took a pliers and bent the edge just a tad then polished them and they fit very well. I didnt however have the skins all the way to the bottom of the jigs. I shimmed it up about 5/8 and it gave just enough relief for them to fit smoothly.

 

[md9680]

I found those ribs don't fit worth beans and no amount of fluting made it better. When driving those rivets, the HS skin pulls in (top and bottom) slightly at those ribs. I think they are just too narrow.... or the skin pouchs "out" between the ribs, making it look sucked in at the rib.

As evidence that some people actually search for the topic before starting a new thread, I found this thread dealing with precisely my problem!

I riveted the middle nose rib and was really disappointed with the concavity it produced -- and only at the middle rib! The end nose ribs went in fine with the nicely symmetrical ogive shape of the upper and lower skin I expected. So, I drilled out the ten rivets from both sides of the middle rib, rechecked the flanges to make certain they were at 90 degrees to the web, rechecked the hole alignment and started clecoing it back in place. But, the entire rib still doesn't seem to be thick/wide enough. Can't even get the skin close enough to make a decent cleco connection without a tremendous amount of inward pressure. Then, when it's finally clecoed (and barely so), the flanges start bending outward from the pressure of the skin pulling away. I tried using the middle nose rib designated for the other side of the HS with the same result. Comparing these middle front ribs to the outer and inner ones reveals absolutely no differences that I can see. Is there nothing to do but make my own up-sized ribs or add several shims?