July 28th, 2013 - Working on the center cabin and fuel valve covers.

I started this post over a week ago and then never got around to finishing it.  Just realized it wasn't finished when I went to start on the one for this week.

 This week I was working on the center cabin cover, the fuel pump cover, and the fuel pump valve cover and plate. For once, this whole thing is pretty basic and doesn't have much in the way of surprises. The center cover will cover the fuel and brake lines. The fuel selector is on top of a short pedestal mounted to the front spar. The fuel lines run from the left and right tanks through the selector and forward under the center cover. Brake lines are from the mains, which are on the outboard forward side of the spar.

Before I got started I deburred the parts and clecoed everything in place to make sure I understood how it was all supposed to go together and that it seemed to make sense.

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This is the plate where the fuel selector will go.  The angled forward part is where the elevator trim will go (mine will be manual).

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Installed the nutplates in the fuel selector cover.

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More nutplates in the center cover.  The cover is laying on its side - it is L shaped, and part extends vertically up the firewall.  The part to the right is where cabin heat will enter the cabin.  Below will be the fuel pump, which gets mounted on the firewall.  There is an access plate that covers the fuel pump, which is what all the nutplates around the open square area are for.

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Once all the nutplates are on, I fit everything back on and screwed it down to make sure the alignment was correct.  Once it's right, the center cover gets shimmed to the correct height, then match drilled.  Nutplates are installed to make it secure yet removable.

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I made up some shims from some scrap wood.

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Center cover shimmed and installed to the correct height.  I made up a drilling template to put the drill bit at the correct height and make sure it didn't move on me.

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Installing nut plates on the center cover.

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Center cover is done except for priming.  Next week I'll start on the flap stuff.

July 21st, 2013 - Priming and riveting the seat backs.

Finished up the seats this week.

I finally remembered to take some pictures while priming.

With the weather (raining when I need to paint) and other commitments,  I usually end up finishing parts up to riveting stage, then going on with the next thing until I can get them primed.  By the time everything comes together, I can have a pretty big pile of parts backed up.

For this batch I had all the seat parts plus some baggage compartment covers.  I wish I'd thought to do the flap cover and fuel/center covers, but I didn't.

Basically once everything has been cut to length/machined, match drilled, deburred, dimpled/countersunk (if necessary) and everything else, the last thing to do is prime the parts then rivet them together.  Sometimes I'll get everything up to drilling (like in the case of the right seat) and prime it first, since it won't be exposed to any weather, drilling after priming is no big deal.

Priming is pretty simple although it takes a while (2-3 hours) with all the prep/setup, waiting for the paint to "cook" (it's a two part epoxy primer), then spraying it, cleaning everything up, then tearing it all down and putting everthing away.

Once all the parts are ready, I go over them and make sure all the parts are scuffed up, then clean them several times with MEK or Acetone, followed by alcohol.

Pile of parts ready and staged for priming.

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I paint outside in the side yard.  Since it's not a finish coat,  the dust really isn't an issue, and the epoxy is not something you want to breathe.  I use my sawhorses and a bunch of large pieces of cardboard to support the parts.

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I also wear long sleeves and a solvent respirator.  The epoxy is kicked off with something that looks/smells like MEK, which is some pretty nasty stuff.

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I use a cheap HVLP gun I got at Harbor Freight aircraft supply at Tim Ribble's recommendation.  It does a really good job for under $40.  If I'm careful I can get a pretty nice finish.

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The epoxy primer came from Aircraft Spruce - AkzoNobel two part.  If you look inside nearly any Boeing aircraft, military or civilian, you'll see this stuff.  Expensive, but tough as nails and dries super fast.  It's mixed 1 to 1.

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I tried a few measuring ideas before I hit on this stainless ladle.  It's perfect, just hide it in the garage so no one uses it for cooking.

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Mix the paint in a mixing cup, then let is simmer for 30 minutes.  The pot life is really good - you've got several hours, which is amazing cause once it is sprayed it literally dries almost as fast as you can paint.  I can turn parts over in 5 minutes. They are stackable by the time I'm done priming and starting to clean up.

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Batch of parts after priming.  Mostly seat parts, but also some miscellaneous parts from the baggage compartment and rear fuse.

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Seat backs and baggage compartment covers after priming.

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Once I had everything primed, it was finally time to nail the seats together.  There are a lot of parts that have to be clecoed together.  It turned out I could use my  pneumatic squeezer w/the Longeron yoke for nearly everything, I just had to clamp it in such a way that it was easy to get to.  Most of the rivets (actually all of them come to think of it) are AN470-4 round head.

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Working on the left seat.  The piano hinges are the attach points to the floor and bulkhead.

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Here's the completed left seat riveted and installed in the fuse.  Really light (< 5lbs) and very strong.

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Here's a side view.  I haven't cut the hinge pins to length yet.

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Working on the right seat back.

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Both seats finished, hinge pins cut to length, bent and installed.

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View of the seats looking aft.  I can finally throw in some cushions, sit in it and make airplane noises. (yes, I did do that.)

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July 14th, 2013

This week I've mostly been working on the seats.  I used the tip for using a metal yardstick as a drilling template to make the drilling of the seat angles/hinges more consistent.  My yardstick is riddled at this point since I've used it for 4 different drilling templates.

The first thing was to fabricate the F637B vertical angles for the seat back stiffeners.  These get cut out of a long chunk of 3/4 x 3/4 x .125 (1/8") angle.

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The F637B gets a notch at one end to provide space for the hinge at the bottom. Not having a milling machine, I tried a couple of things - turned out it was easiest to just file it.

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There is a left and right hand version required for each seat, so you have to pay attention not to make two of the same part.

 A piece of piano hinge gets cut and drilled for the bottom (this is what attaches the seat back to the floor pans). There are three separate identical lengths of matching piano hinge riveted to the floor skin. This allows for some fore/aft adjustment for leg room as well as a bit of reclining.

 Since I also drilled several attach points for the rudder pedals, the plane will easily accommodate a variety of pilot sizes, although any adjustments will have to happen on the ground.

 Once the verticals are finished, there are two horizontal angles made from 3/4 x 3/4 x .063, one at the top and one at the bottom.

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Finally all of these parts (including the length of hinge) are match drilled to the seat back, which is a corrugated sheet of aluminum. The corrugations provide additional stiffness.

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Here's the completed assembly after drilling.  The only difference between the left seat and the right seat is the orientation of the hinge at the bottom.  Left side has the hinge set up one way, the right is exactly opposite.  Other than that they are identical.

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A seat back brace F638 is riveted to another piece of piano hinge, which is then attached to the upper back of the seat. This provides sufficient flexibility to accommodate any seat back adjustment, as well as allowing the seat to be folded forward if need be.

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This would probably be very handy in a tip up canopy RV, although with the sliding canopy I'm planning on, I don't see much of a need.  It would also be very easy to take the seat back out if you had something to carry and didn't have a passenger - *that* I could see doing at some point.

Here's the seat clecoed together and installed in the cockpit. In this shot it is in the middle position of the floor attach hinges.

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Here's a side angle shot of the same thing - gives a better idea of how it all fits together. The F638 brace at the top is a tight friction fit into the bulkhead.  The grey angled pieces sticking out of the floor are the seat belt anchors.

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It's amazing how light and strong this is.

 The seat will be a lot more comfortable than it looks. There is a spacer cushion that will be shaped to fit the depression and fit level with the forward seat floor. Then a seat and back cushion will be installed on top of that, so it will end up sitting pretty much like you would in a car. Here's a shot of what an interior looks like all decked out.

July 7th, 2013

Needless to say there has been a lot going on (Becca graduated from High School, Paul & Becky's wedding, electrical problems with Becca's car, repairing/replacing raillings in porch and repairing some rot in one of the columns, new thermostat for Becca's car, working on the Ody for a long road trip, SOAR for Becca at UNCC, Daytona vacation, and repairing some old fence sections and replacing a rotted fence post among other things).

I have been working on the project as time permits, but haven't taken the time to post an update in a while.

Since the last update I've match drilled and installed the aft seat skins, installed the hinges for the seat attachments, fabricated and installed the tunnel support cover, and started working on the crotch strap attach brackets.