Pushing on the firewall

If anyone wants to follow along at home, I'm on page 31-6, step 1.

I clecoed the sub panel into place. The F-1044B Angle falls flat on the F-1001B Firewall Upper Angle. Everything seems lo line up, except the ribs are pushing the top of the firewall out of alignment.

Part of that I can attribute to the firewall being dimpled already, but the ribs are not. But I'm not convinced once the ribs are dimpled the firewall will once again be flat.

Anyone else have this problem during their build?

Thanks.

Jeff

The world is not flat

The plans don't tell you this, but in fact the firewall is not flat. The top section is canted forward at a bit of an angle as set by the upper fuselage ribs. This came as a bit of a surprise to me when I set it up also, not that long ago.

You should check your rib alignment. Several builders, myself included, have had problems with the alignment of the front holes on the upper forward fuse ribs. You may or may not be OK depending on the age of your kit. Here is my description of the problem and how I fixed it:

http://tasrv10.com/?p=1562

Adrian, thanks so much. Thought I'd really managed to screw something up.

Yeah, a little note in the plans about the firewall not being flat would have been nice.

Jeff

A little history!

Freightdawg said:

Adrian, thanks so much. Thought I'd really managed to screw something up.
Yeah, a little note in the plans about the firewall not being flat would have been nice.
Jeff

Click to expand...

Originally the firewall on the RV-6 was flat. Then later it became an option to cant the top forward so that it was perpendicular to the cowl seam. This makes for easier insertion of the hinge pins. Of course over the years people have migrated somewhat away from using hinge attachment across the top of the cowling.

I went through the exact same thing about a week-and-a-half ago. Saw the firewall pushed forward by the upper fuse assembly and thought "Now what did I do wrong?" I thought dimpling the ribs would help. It didn't. So I thought to myself,


Inserted what seems like a 1000 clecoes in the upper fuse assembly, firewall and upper fuse skin. Everything fit and it looked great. So, I just figured that the firewall is canted the very exact 7.3 degrees forward like the intermediate panel just aft. This also explains why the firewall top seemed to always lean forward when unsupported.

** I've found this is good advice before trying to "fix" things, run to VAF to research, or call fellow EAA1189 member Weasel for help

Freightdawg said:

If anyone wants to follow along at home, I'm on page 31-6, step 1.

I clecoed the sub panel into place. The F-1044B Angle falls flat on the F-1001B Firewall Upper Angle. Everything seems lo line up, except the ribs are pushing the top of the firewall out of alignment.

Part of that I can attribute to the firewall being dimpled already, but the ribs are not. But I'm not convinced once the ribs are dimpled the firewall will once again be flat.

Anyone else have this problem during their build?

Thanks.

Jeff

Click to expand...

Me too!

I just got to this section and thought the same thing. I also concluded, after dimpling and clecoing it all together, that everything was as it should be. Unfortunately for me, I had to uncleco it all again because I screwed up fluting the top "D" and "E" angle pieces that secure the panel to the skin, so I had to order replacement angle to make more parts. Waiting on them now.