Section 27 Firewall

RV14 Build November 19-22

Firewall

The 22nd is officially 1 year since the kit arrived!! It feels longer and I can't believe how much I have gotten done!

The firewall have a decent amount of small parts but nothing major really. Countersinking, prep for prime, prime, and rivet.

Dimpling the firewalls

Back riveting the structure to the firewall.

Building the exhaust channel. I made a mistake hear and riveted without al the pieces. The rivets looked too long, that should have been a red fag, someday ill learn to listen to those.

Firewall 14 Hours

Section 26 Riveting on baggage ribs

RV14 Build November 14-19

MID Fuselage Lower Structure

Now that everything is primed time to assemble. Admittedly I thought that this part would go without issue, but that didn't turn out to be the case. The lesson here, and its really hard to do, when you start to make mistakes you need to stop for the day. You can't power through it and it doesn't usually start to go your way.

Started out with seatbelt lugs and baggage rib assembly. These will turn out to be the problem in the future, I think because I put the primer on too thick and the holes didn't want to line up with the ribs and doubler to the spar.

Building the gear brace brackets. You have to countersink for a thicker skin and I was thinking maybe the standard practice of setting the countersink cutter to the proper depth for the rivet and then going  7 clicks, .007, deeper wouldn't be enough. I added a few clicks arbitrarily and after doing some research it seems the big threat is over counter sinking because you dont get good contact between the parts. They shouldn't lay flat when you put them together because the curve of the dimple radius is larger than the counter sink. not counter sinking enough doesn't negatively affect the strength of the bond.

Dimpling the skin and installing the skin stiffeners.

Installing the skin brace

Installing and riveting the MID Forward Lower Structure

Building the step attach assembly. I am going to put on the optional steps so I did the Tr-Gear only steps in this part. These where a little tricky to rivet together, really glad I had help.

Installing the step assemblies and the baggage ribs. This is where the trouble really came to a head. The rivets in the ribs didn't want to line up with the holes. With my riveting partner we where able to work through most of that, but after he had to leave I tried to rivet on my own and didn't get even pressure on the bucking bar and gun and pushed the skin out around the rivets shop head. I ended up drilling out the whole rib. Sanding and re-priming the areas that need it. Using the squeezer the flatten the metal back out. Then cleaning up the holes. The top hole in drilling out the rivet I drilled into the rib a bid, not all the way through, but enough where combine that with the minimal edge distance I was worried (start of the plan to repair IDK yet) so I build a doubler for the rib that Ill flush rivet to the aft side of the rib flange to reinforce that hole, The next hole down is too large now so I plan to drill that out to 5/32 and either put in a cherry max or a solid rivet.

Im not an engineer so trying to find out if using a cherrymax rivet in the second hole would work led me to the MMPDS handbook section 8. It looks like the strength of a driven 3/32AD rivet is 389lbs in single shear but multiplied by the sheet thickness factor is 374lbs, and the unit bear strength 411lbs so the single shear is limiting. The strength of a CR3213 5/32 in .032 thick material Yield strength is 375lbs. The handbooks says the yield strength is the shear to create a 4% nominal diameter change, since the rivet shear is 1030lbs the yield shear would be limiting. From what I can tell the unit bearing strength and the Yield Strength is the same thing.

Cherry Max 

So that plan to repair is TBD but this is the plan.  So section 26 is complete besides the 1 baggage rib needing to be installed and the baggage ribs need to be riveted to the skin, have to wait for Matt to get back for this!

MID Fuselage Lower Structure 28.5 Man Hours

Section 26 Baggage area ribs and skin

RV14 Build November 8-11

MID Fuselage Lower Structure

Prepping the remaining parts of section 26 and priming. Can't stress this enough, when you have someone willing to do edge work and prime prep it makes all the difference in the world!! Get a Matt!

Back at home prepping parts.

This is how I prepped the bottom skin, on my bathroom floor and rinsed it in the shower. It is much harder making sure you get all the residue off the larger skins, it too many rinses and still several passes with Acetone to get it completely clean and paint ready.

The other side of the bottom skin, Im going to prime where the skins overlap.

Skin wrapped up ready to transport back to the shop, put a towel in there to make sure the edges don't dig into the metal.

All the remaining parts of this section plus the skin to prime!

Getting after it!

MID Fuselage Lower Structure 18.5 Man Hours

Section 26 Riveting on Seat ribs to Bulkhead

RV14 Build November 7-8

MID Fuselage Lower Structure

Now that the seat ribs are primed Im fitting everything to the skin, flutting the outside ribs to match the skin curve and building the seat rib area.

Seat ribs are cleko in and ready to rivet. This is Matt, he has helped me build almost half of the kit, everyone needs to find themselves a Matt when they start this project. #Teamriveting

The only problem with Matt is we get in a groove and I stop taking pictures, So here is all the seat ribs riveted on excepted the most outer ones.

I didn't have help to rivet on the 2 outboard ribs and it went okay, if you consider drilling out 3 rivets okay.

All the seat ribs riveted on!

I jumped half a page in the plans because the next few steps parts aren't prepped yet but here we are installing the bulkhead to the assembly.

Installing the bulkhead angle.

Almost installed the rib on the wrong rivet line!! Be careful here because it does line up with the holes, I was lucky to see the rib looked a little curved.

Bulkhead angle installed.

Looks like airplane parts again!

I was wondering how long this section is before it is joined with the empennage. Need to make sure I have enough room in the shop! Roughly 89 inches.

MID Fuselage Lower Structure 10 Man Hours