[Phil]

I'm getting ready to start rebuilding a new and improved VS. My first attempt wasn't very attractive. Included in the old VS was the famous RV-10 bump. I thought I removed a bunch of material, but apparently I didn't remove enough.

This time around, my plan was to go ahead and cut them back the the min edge clearance for 3/32" rivets. That would give me the best possible opportunity to avoid "the bump" but still be within the minimum acceptable limits.

So I measured the min edge distance for the 3/32" holes on the middle nose rib flanges and used a sharpie to outline the area I wanted to remove.

That's when I found out that I was intersecting a hole in the webbing of the rib. If you look at the photo, my line is drawn through the hole.

Two questions:
1) What is the purpose of this hole.

2) Is there an edge distance I need to maintain from it?


Thanks,
Phil

 

[az_gila]

Tooling hole

Phil... that looks like a typical Vans rib tooling hole. I bet here is also one on the center line line of the rib near the spar... It exists to line up the forming dies...

No problem cutting through it as long as shortening the rib is an "approved" fix....

gil A

 

[petehowell]

Tooling Hole

My guess is a tooling hole used in manufacturing the rib. I'll get shouted down if this is wrong.

 

[rv6rick]

Phil,
Yup on what the other guys told you about the hole....BUT.....by cutting where you drew the line you still have a very good possibility of getting a little 'outty' near the leading edge of the stab (actually 2....1 on each side).....just back a little further . Personally, I'd pass.

What I always do is gently run ALL of the rib front EDGES across my belt sander and give them a taper, take them back about a half inch. Then take a real small round file and and round out the inside edge of the belt sanded taper (the 'now' thin part) to provide a relief point. No 'outties'...period.

Mels post below is on target.

 

[Mel]

You don't need to cut ANY material from the ribs. If the flanges are properly bent and the edges rounded, there shouldn't be a problem.

 

[Phil]

You don't need to cut ANY material from the ribs. If the flanges are properly bent and the edges rounded, there shouldn't be a problem.

Hmmm... I don't quite understand. These photos are from Mark and Angela Lanier's site, since I don't have any with me.

The RV-10 VS nose ribs are too long. They definately require the removal off the nose to avoid a bulge in the skin. This is discussed in the HS section, but it is omitted in the VS section.

Without removing material from the ribs, I don't see any way you can install them without creating a huge bulge. I really don't even think you could cleco the skin into position because the nose ribs will hold it off.

 

[Phil]

Phil,
Yup on what the other guys told you about the hole....BUT.....by cutting where you drew the line you still have a very good possibility of getting a little 'outty' near the leading edge of the stab (actually 2....1 on each side).....just back a little further . Personally, I'd pass.

What I always do is gently run ALL of the rib front EDGES across my belt sander and give them a taper, take them back about a half inch. Then take a real small round file and and round out the inside edge of the belt sanded taper (the 'now' thin part) to provide a relief point. No 'outties'...period.

Mels post below is on target.

Rick,
Is this similar to what you're doing?

 

[Rick S.]

Phil,

I think that's exactly what Rick is referring to. Thats what I did to my nose ribs along with some small metal tooling to get rid of the sharp edge and stop it from diggin into the skins. I think they came out pretty well. Mel is correct on the material removal post but the HS ribs on the -10 are a different animal that Van's doesn't want to address for some reaason.

You can cut the nose back if you want just maintain your edge distance from the front most hole that the skin attaches to. The large hole is in fact a tooling hole and is not used for anything except to put a big cleco in to align the rib left and right while trying to fit the skin to the rib. That's a hint/tip.

 

[ddnebert]

Scotchbrite wheel

I found that using the Scotchbrite wheel on the grinder worked extremely well for completely rounding off the offensive edges on nose ribs.

 

[rv6rick]

Phil, Yup...that's it!

Good pic Phil...that's what you want to do. Take off the 'forward corners' as far back as you need to to provide the necessary relief. To be sure it's best to trial fit each rib after you make the modification, being carful that you don't have to 'jam' them into place.

Rick,
Is this similar to what you're doing?

 

[Bill Cannon]

Phil,

How did they wind up fitting? Did you grind it down any more than the picture or did that do the trick?

Bill

 

[Phil]

Bill,

I haven't had a chance to try it yet. I had already shorted the top and bottom nose ribs when I found the tooling hole conflict on the middle nose rib, so I ordered replacements for them.

Hopefully they will arrive today or tomorrow.

I did a practice run on one of the ribs I shortened, and it didn't appear to be that difficult.

Once they show up, I think I'm going to start at 1/4" and increase the notch from there.

I'll post some pics of the process, when I get them in....

Phil

 

[Bill Cannon]

Thanks Phil,

Maybe I'll be able to be a mine sweeper for you in the future. Have you done any work on the rudder trim yet? That elec trim looks like it would do the trick but I am a little intimidated about doing a mod so early in the process. Early on in the building process even sticking to the plans makes for a challenging project. It does seem the consensus is that some sort of rudder trim is needed whether it be a bend tab or electric.

I'm about to fly home from India with a Captain who has built (not an RV) and is an A&P. He'll be sick of my questions but I may be able to kill some time talking about rudder trim for 15hrs.

Bill

 

[Phil]

I'm starting on the rudder trim and I'll post up some info on it too. Most of the materials arrived yesterday, but my Servo and dimpled nutplates should arrive today.

After they show up, I believe I can get started on it.

Phil

 

[Phil]

This morning, I got started on the bottom nose rib.

I started off marking 3/16" from the tip of the nose rib.

Then I went to the belt sander and tapered the rib from the tip to the 3/16" line.

Then I used a small round file to clean out the thin material between the flange and web.

After test fitting, I found I was still getting a very small bump. So I continued to removed material until I didn't have to jam the rib into the hole. (I still feel like I have to press it into position, though. It's not an easy fit. I just didn't feel like I wanted to remove any more material.)

Here is the rib cleco'd into position.

Does it look like I did it correctly? Or did I remove too much?

 

[Phil]

I went ahead and did the other two nose ribs. The bump is there if you look closely, but you've really got to look hard to see it.

As far as fit, they aren't a breeze to put into position. It still takes quite a bit of effort.

In general, I'm happy with the way it turned out. As Rick mentioned before a half inch seems to be the magic number. All three ribs required a 1/2".

Phil

 

[rv6rick]

Hey Phil,
Good job...your comments and pics will help the next guy(s) down the line! Nice touch dressing up the notch with your file!

Yup....about a half inch .

Keep up the good work...these little tricks will make your bird stand out from the rest when it's done!

 

[Bill Cannon]

Thanks for the info Phil. Very informative and detailed.

Bill

 

[Wills_9A]

I have long since sold my 9A for financial reasons opting for something a little more in my budget...a Sonex. I did learn a little trick from Sonex founder John Monnett about this one however, go out and buy a pattern notcher for sewing, then use it to notch the tips of your ribs...trust me!



Will

 

[mikehoover]

Flute the web

You might try fluting the web at the nose end on either side of the tooling hole to bring the flanges inward.

 

[Phil]

You might try fluting the web at the nose end on either side of the tooling hole to bring the flanges inward.

That's a great idea. I wish I had done that right after notching them because I still ended up with a bump on the middle nose rib.

Phil

 

[Mike S]

One thing here concerns me a bit----------

Regarding the photo of filing out the notch at the front of the rib------unless you follow up with a "craytex" tip or some other way of smoothing the inner radius of the notch, you are creating stress risers by using the file at right angles to the edge of the rib.

Couple that with the fact the flange is having to be forced into the leading edge curve, and you have the perfect recipe for developing a crack across the flange, at the notch.

 

[Phil]

I should have mentioned that I used 280 grit emery cloth within the notches to radius the filed area. That way there are no sharp 90 bends.

 

[Phil]

I just talked to the guys at Vans and they said they really hadn't heard about the VS nose rib bumps.

But I did ask what he thought would be acceptable. The first thing he suggested (I didn't bring it up as an option) was fluting the front of the rib.

He also suggested radiusing the nose ribs. But that would only buy you .020 or so.

I asked about creating releif notches and he said that shouldn't be an issue as long as you still have minimum edge clearance for the rivets.

If I had it to so over again, I'd do both notching and fluting.

Phil