Re-framing, sheeting and Sans tail wheel

Over the days (mid-week) I've been trial fitting the rebuilt center fuselage (F-414/415 & 407/408).  It really all goes together as one unit.  I wanted to make sure I had everything aligned well and that the main spar / trailing-edge spar spacing (F406 to 407) spacing was dead on for both sides.

I assembled the core (just 414 & 407) and put it into the space and I let it sit for a night (so I could sleep on it).  Yesterday morning,  I drove the rivets and made it permanent.  Then  added the rest and finished the F-418.

On The F-418, I installed the extra washers on the elevator bell crank before driving the rivets. 

I built the replacement 3/4" angle from the spar to the lower engine mount weldments.  It had cracked from wholes too close to the edge, easy replacement.

So the core is framed. I'm still waiting on the big long 9' long 3/4" x 1/16" angle for the lower-aft longeron which had a minor bend.  But I drilled out the tail and pulled the old bent angle out.  While I was in there, I also liberated the tail wheel.  There is no-longer a tail wheel in this aircraft!

The tail wheel weldment provided some hard-points and stiffness in the tail for the elevator and rudder.  So, I replaced the bolt for the second to last bulkhead which has the pair of elevator attachment bars and I plan to install a 1" angle for the lower rudder attachment inside the last bulkhead.  

Finally, I started cutting the sheet F-422 and 423L/R.  I used the existing sheets as a rough template.  I spray-painted the outline and holes (I plan to back drill for most, but having the old holes will help in places where I can't back-drill and I'll have to drill outside blind) onto the new sheet and cut with 2 mm trim all around.  I found I was able to cut the F-423 pair from one width, so I should have quite a lot of 0.032 left over.

It's looking like a fuselage again

Yesterday was many hours doing a few holes.  Lots of interlocking parts, some new, some old all has to match.  Prepped the F414, F415 sets and F-418R.  It's all ready to bolt back in.  All the steel parts are out for powder coating. So I'll wait for them to return before I go further here.  I'm worried the control center section may be a lot harder to get when this section is installed.  I can't remember and it's not worth risking for a few days break.

Replacement bulkheads and firewall/nose plans

The new fuse bulkheads arrived from Vans yesterday.  I have prepped them all and started assembling the fuse center section.  The whole thing fits back together similar a jig-saw puzzle.  You start with the rear seat back bulkhead, then the floor bottoms tie it all together with the rear spar bulkhead. 

I'm also trying to match the important pass-through for controls and wiring and accessories (e.g. flaps) correctly as I go.  I remember how difficult it was to trying to get the elevator tube to clear those aft-cockpit bulkheads after the fuse was all together, I really don't want to repeat that.  The plans call for a hole that is far too small by at least half.  I'm matching the parts as I replace.

I found the original builder added an extra bolt to the rear seatbelt attachments which causes rear bulkhead interference, far too much "cut-out".  I removed the fourth (calls for three) bolt and minimal F-408A-L/R bulkhead cut-out.

Arrange the nose gear around the exhaust is tricky.  RV-4 stock has a wide narrow slit.  This may work well as the straight pipes can exist around the center where the gear reinforcements will be. 

I'm contemplating using the RV-8-style (no-cheaks) nose.. I'm confident it can be done but causes changes that ripple up to the spar.  The fuselage box is far wider.  33" vs 24".  I would need to replace both front sheets with custom (3" taller), build a new wider F-402a,b,c and the belly sheet will not be stock anymore.  It's being replaced anyway.  I would fit a stock RV-8 cowl and RV-8A engine mount if I went this route.

If I stay true to the RV-4 nose, I will need to figure out a bottom attachment for the nose-gear... The rest would stay pretty stock.

Either way, the rudder pedals are going to be an issue as they attached to the firewall, which is now flat.

A major repair project

So about three years ago... I acquired one heavily damaged and stripped RV-4 carcass.  It has a lot of hardware, and good parts, but about a two dozen major parts that are bent beyond repair. 

Here's the list of what has been removed and replaced with new;

Bulkheads

F-401 - Firewall. trashed  and bottom angle bent and replaced  
F-418-R - Bulkhead under rear baggage,  bent at the rear seat attachment.
F-407A-L/R - Rear seat bulkhead, bent on the bottom seem
F-414A-L/R & F-415A-L - Bulkheads under the pilot, bent at the spar attachment
Sheet

F-420-L - Front-side, bent at spar attachment
F-422 - Big belly sheet, very beat up (from dragging) and buckled under spar
F-423-L/R - Beside pilot, bent at on both ends, both sides
F-425- Turtledeck, bent near tail from rudder
F-426-Rear belly pan, buckled near rear back-seat seem and very beat up (from dragging)

Angle (they have no part numbers)

3/4"-1/8" angle from lower firewall to top-of-spar bulkhead on the right side bent/replaced 3/4"-1/16" angle from rear bulkhead to tail replaced on the left side, bent.

While this seems like a large list, there are hundreds of parts that are in good shape, completely undamaged.