Pg 10-14 Breaking Edge of Skins of Tailcone?

The first note on page 10-14 says to break the edges of the skin that will overlap. Looking at the F-01473 side skins it looks like the complete bottom edge needs to have an edge break. What about the forward, aft and top portions of the side skins? Do all four sides need an edge break? Any advice is appreciated.

Thanks
Bill Gardner
140849
S12049

Break the edge that will be exposed/seen in the finished product. The breaking of the edges is so when riveted the seem stays tight, without the slightest breaking of the edge the top skin will curl up ever so slightly leaving an unsightly edge fit.

And remember, if you can see the break, it is verging on too-severe. You really want a very minor break.

1949MGTC said:

The first note on page 10-14 says to break the edges of the skin that will overlap. Looking at the F-01473 side skins it looks like the complete bottom edge needs to have an edge break. What about the forward, aft and top portions of the side skins? Do all four sides need an edge break?

Click to expand...

I'm resurrecting this thread because I'm at this stage in my build and the OP's question didn't really get answered. I understand any edge that overlaps another needs to be broken. But, even after looking at the plans multiple times, looking at the wiki plans, etc, I'm still not sure which sides of the aft fuselage skins need to be broken.

Of course, this would all be clear if I was at the point of riveting the skins on. But, the plans call for the skin edges to be broken then dimpled and many pages later, riveted.

Can anybody point me to a post that describes specifically which edges of the aft fuselage skins need to be broken?

The overlapping edges are broken - the edge of the outermost skin. For example,if you visualize water flowing down the skin, the broken skin is on top of the skin below so water cannot easily enter the lapped joint.

MED said:

The overlapping edges are broken - the edge of the outermost skin.

Click to expand...

I understand that. Without trying to partially assemble all the skins, there is no easy way to figure out which edge overlaps another. As an example, what about the vertical edges of the side skins or the fore and aft edges of the top and bottom skins?

I soooooo wish Vans would have spent an extra one minute while creating the plans by simply drawing an arrow pointing to the sides of the skins that need to be broken.

I guess what I need to do is not follow the plans in order. I will wait to break and dimple the skins unit I'm actually asked to rivet them in place. That's the only way I will really be able to visualize how they all fit together.

Take a look at the page for joining the fuselage to the tailcone. That will make it more clear I think. By memory I applied a break to the most forward edge of the narrow skin that makes up the rear window curve, and the lower edge of that same.

I'm just going to break all the edges. I figure they all need to lay as flat as possible.

I wouldn't, an edge that is "inside" the stack between substructure and the top skin should lay as flat as possible. Take the time to look forward and see what is "topmost" and what is below the surface.

Take a look at section 30-03. You can see that the upper "extension" that runs under the rear window is the top most section of skin. So the red arrows indicate where you should apply the break. The lower area indicated by the blue X tucks under the fuse side skins, so no break on these.

georgemohr said:

I wouldn't, an edge that is "inside" the stack between substructure should lay as flat as possible. Take the time to look forward and see what is "topmost" and what is below the surface.

Click to expand...

I've already spent a ton of time trying to figure out how the skins overlay each other. At this point I'm just super frustrated. Vans does a great job overall with their plans. But in some cases (like this) they drop the ball big time. Please Vans, tell us first time builders WHICH edges to break. Not all of us have built planes before. We're not all engineers.

It's easy to figure out which edges to break on things like control surfaces. But, the rear fuselage has multiple skins and the plans don't clearly show how the edges of the skins connect. Do they butt up to one another? Do they overlay? It will be obvious when we're riveting the skins on. Not obvious when it's raw sheets of aluminum sitting on a shelf.

Soooooo frustrating. Sorry for whining but I get really frustrated at parts of the plans that I struggle with that I know Vans could have made clear with literally one additional sentence or two arrows or whatever.

I'm on page 10-14 (lower side skins). I broke the top and bottom edges. Haven't got to the upper skins yet.

bertschb said:

I'm on page 10-14 (lower side skins). I broke the top and bottom edges. Haven't got to the upper skins yet.

Click to expand...

Hi Brian - sorry to resurrect this thread again, but just wondering if you had a resolution on this. I'm also struggling to figure out what to break on the F-01473-L and R parts. I think breaking the bottom is clearly correct. If I understand page 10-31 correctly, the upper skins go over the lower ones, so there's no need to break the top of F-01473.

Page 30-03 seems to show the forward fuse on top of the aft fuse, so no need to break the forward section of F-01473. And I'm not sure what goes aft of F-01473 - the rudder I suppose. So no aft break needed.

That's my interpretation. Does that sound right? I know you said you broke the top edge - did that turn out to be correct or not?