RudiGreyling

RudiGreyling

Well Known Member
Hi Guys,

I'm busy bending and fluting the main wing ribs when I noticed there are bumps on the nose ribs on the top side. The bumps are to the outside.

The pictures don't do it justice but the bumps are high to the outside, especially at the rivet holes.

My questions are:
1) Is this normal or is this a manufacturing fault? It looks like the skin will not sit flush there and hence I will get a waive leading edge.
2) If it is normal, do I need to fix it and how?

Thanks in advance,
Rudi

nose_ribs_01.jpg

nose_ribs_02.jpg
 
Rudi:

The flutes go between the ribs, and should face away from the skin. The ribs in this condition as formed is normal. they are formed in the soft contition and heat treated after forming. The bumps you see are a result of that process.

Lay the rib down on the fluting drawing and flute the ribs by making a mark on the rib next to each mark on the drawing. Use a flat table or staright edge after fluting to ensure that the rib is staright. A little care here goes a long way towards nice looking wings. The pre-punched holes in the rib should line up with the holes in the skins without any preload when you cleco the skin on. In general, it is better to have more flutes with less depth than fewer flutes with more depth. Just work to get those ribs straight and the flanges at 90 degrees, in the end you'll be glad you did.

Best Regards,
Jon Ross RV-80094 N207RV
A&P IA
Bayport, NY
 
Captain_John said:
Rudi, Mine look exactly the same. They didn't appear on the skin on my project... other things did!
:D CJ
Click to expand...
Yes John I read about you dropping the Bucking Bar...:(

Jon Ross: thanks for you post, but I am interested to know how to get those bumps out if required, since they are to the outside and some on the holes. I understand how to flute to the inside between the holes and bend the flanges to get a straight rib, but these bumps worry me! They look like the will interfere with the skin laying flat on the flange, even after fluting to the inside, since you cannot flute on the holes.

Did you guys fix it and how?

I am concerned about the the ones in the circles:
nose_ribs_03.jpg


Thanks
 
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It's amazing what happens to metal in a forming process such as that used to initially form your wing ribs.
The metal gets deformed, as you see, and it is up to you as the builder to do the final work in preparing the pieces for installation.
You will have to use your seamer to flatten out these bumps and then move forward to the job of making sure the flanges are at 90 degrees, through bending and fluting. It can be tedious work, but it can be done. Once you get the hang of it, after a couple of ribs, it will go much faster.
If folks tell you to go ahead and install it as is, that the riveting process will straighten it out, you are getting bad advice. Get the best possible fit you can and the finished job will be much better.
Be creative in using your tools. For example, use the side of the seamer to flatten out narrower spots or use some duck bill pliers, with tape on them, for really small spots.
In summary, smooth out the bumps first and then work on fluting in the correct spots, as detailed in the plans, and getting the flanges at 90 degrees. Do not forget to deburr all edges before starting the process. There was an earlier post on this topic, about a week ago, that you should review.
Good luck.
 
Rudi:

Sorry, I did not mean to insult you; just trying to help...

Use the seaming pliers on the rib flanges. When you flute the flange, it should help to pull down the bumps. Another way to flatten those bumps is as follows:

1) Make a form block with the proper bend radius and rib curve on it. Hardwood is best.

2) Use a mask block on the outside of the rib web (vertical surface) and the form block on the inside.

3) Place the rib, form block and mask in a vice, tightly squeezing the rib.

4) Using a piece of plumbers lead as a malleable tool with a dead blow hammer, work the edges of the flange with the bumps down against the forming block. You will find that you need to build 7 degrees or so into the forming block to allow for metal spring back. That is to say, the forming block with have an angle less than 90 degrees, say 83 degrees.

This method describes how we make ribs of 2024 O before we heat treat them.

Hope this helps,
Jon Ross
 
Rudi,

Talk about "bad advice". First of all, this ain't all that bad. However, I can understand that you might want to flatten the bends that are over the holes. I would highly advise against usign a seamer to fix this. These dents are along a curved edge, so a seamer would make a mess out of this, and do more damage than it will fix. If you want to get rid of these dents, then use some sort of block that you can position the inside of the flange against, and then tap the dents with a soft hammer. I would use my plastic coated dead blow hammer, or a light touch with a ball peen hammer. Just don't wack things too hard.

Tracy.
 
greylingr said:
Hi Guys,

I'm busy bending and fluting the main wing ribs when I noticed there are bumps on the nose ribs on the top side. The bumps are to the outside.
Click to expand...
Rudi,
Using your fluting pliers, place small flutes in the usual place to take up some of the stretch caused by forming the rib flanges then reverse the pliers directly over the protruding bumps and very lightly press them flat. You can move the pliers to either side of the offending bumps and with a little care, you should be able to easily blend and remove them.

Good Luck!

-Mike
 
thallock said:
Rudi,
Talk about "bad advice". First of all, this ain't all that bad. However, I can understand that you might want to flatten the bends that are over the holes. I would highly advise against usign a seamer to fix this. <snip>
Tracy.
Click to expand...
This thread has gone full circle and guess what Vans got to say:
"Rudi, the ribs look normal... you have yet to dimple them and a lot
of it will disappear then.... build on!! Van's"

Well I do not like those bumps, I am going to take a bit of all the advice and try my own method of getting them out! I just thought there was a universal tried and tested method everone would agree on.

A bit of time spend here might reward me with a better product in the end. Now is the only time to do it, if I don't I might regret it later.

Thanks everyone I appreciate your input.

Kind Regards
Rudi
 
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