Sept 1st, 2013 - fuel, vent and brake lines, mount the wing

Rebecca wanted a new desk (she'd been using a really old computer desk I built about 30 years ago, and was tired of it), so I took about 4 days to do that.  I'll try to post a picture if I remember to take one.

Once the main gear weldments are mounted, Vans wants you to install the wings.  They do mention an option to do one at a time (not real inclined to do that since I want to make sure they are square not only to the fuse but to each other).

Anyway, the more I looked and thought about it the more it made sense to me to do the vent, fuel and brake lines first, since they have to attach to the wing, and there is little or no room to work if the wing is on.

I did do it that way, and it seems to have worked out for the best.  I didn't ruin any tubing, and there was more than enough to leave extra on the free ends where they will attach to the tanks.

First thing I did was start on the vent line.  It looked like it would be easier, and give me a chance to get used to working with aluminum tubing, doing the bends and flares, and generally just getting the hang of things with a relatively easy part.

First one I did was the right vent line.

There is a bulkhead fitting through the bulkhead.  I decided to start there, then work up and forward.

I used a 90 degree tubing bender I picked up at Home Depot to do some of the bends.  Once you get the hang of it it works fairly well, although figuring out where to start the bend so you'll end up where you want is a bit trickier.  I tend to err on the "too much" side then trim back if need be.

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I used the bender to put in the curve where it needs to clear the rudder cables.  Adel clamps are used to hold the tubing along the bulkheads.

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The other "tool" I ended up using even more is a spring tubing bender - you can just make it out in the lower photo.  This allows you to make free form and complicated bends pretty easily, and the spring will make the tubing keep its shape so it does not collapse.

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The box on the floor next to the tubing has all the AN fittings - these are mostly flared fittings for the fuel and brake systems.  The hardware is all aluminum, but is anodized, which is why it is all blue.  The flared fittings are 37 degrees.

Once the tubing is to the right length, it is trimmed, squared, deburred, then flared with a flaring tool.

Here's the flaring tool - Parker Hannifin I got from Aircraft Spruce.

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Here's a close up when I'm doing a flare.  There is an index piece incorporated with the clamping mechanism - with it open, you run the tube up against the index and that will ensure the tubing is in the proper place relative to the die and (mandrel?  not sure what the flaring part is called...).  You can see the tubing in the center held by the dies.

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Finished flare - all aircraft flares are 37 degrees, unlike cars which are usually 45 degrees.

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Here's the completed right side vent line.  The vent fitting exits through the floor and is angled forward to catch the slipstream and force air into the tanks.

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Left side is a mirror image of the right.

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The last part of the vent line is to make the short tube that exits through the fuse side to attach to the fuel tank vent fitting.

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Once I did those, I started on the fuel lines, which are 3/8", so quite a bit heavier and stiffer to bend.

I came up with a useful technique for running the lines.  I bent and flared the inboard ends first (notice something missing??? argh!), then ran the tubing outboard.  I installed my spring tubing bender with a curve that led the fuel line out through the gear weldment hole.  The fuel line just slid right through, bending as it went.  Much easier than trying to bend, push, bend around the corner and out through the side.

By the way, it's easier if you take the bushing out and tape the hole so the tubing won't abrade on the way out.

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Fuel lines done - test fitting the Vans supplied fuel selector.

I'm still

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Working on the right brake line.  I used the spring tubing trick here as well.  *Much* easier.

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Running the right brake line forward through the center section.

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Labor Day Becca helped me install the wing.  I'm not drilling anything, just test fitting and running through the tasks Vans spells out.  At first it was hard to get going, but I realized I was hung up on the rear spar bracket and bottom skins. Once I got those sorted out it went fairly well.  There is more dihedral than I thought.

Probably spent 30 minutes getting the wing on.  I'm sure next time it will go much quicker.  Fuel tank is not installed in this pick.

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Rear spar attach.  Looks like I have plenty of edge distance.

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Fuel tank installed.  Starting to look like an airplane. :)

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Aug 18th, 2013 - finish crotch strap, start on main gear mounts

This week I finished up some unfinished stuff in the cockpit, then moved on to the main gear weldments.

 When I was doing the left crotch strap attachment, I missing priming the right hand side, so I had set it aside until I got it primed. I did remember it last time and had it sitting around waiting to finish.

 Once I finished up the flap assembly I decided to knock it out - seemed like a good time and I wanted to clear up any unfinished stuff before I started moving on with the forward cockpit.

 The second one went in much easier. I'd figured out the angles with the angle drill and how to line it up with the left side, so it went pretty quickly. As usual with this stuff, I made all the mistakes on the first one, so the second one came out like I would have liked the first to but didn't. :)

Brackets match drilled and nutplates installed.

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The second one I had a much better clamping system to space it correctly. I used some scrap that was the right thickness and a bunch of cleco clamps to hold it tight for drilling the seatbelt attach as well as into the ribs.

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I also clamped the snot out of it when it put it into the fuse for drilling. It doesn't look accessible in this pic, but the forward side is easily drilled.  The black thing in the middle is my small square to make sure it's vertical.

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Fini

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Next thing to do was the main gear weldments.

 I'd been dreading these. When I was tired one day and fooling around I tried getting one in and couldn't - the hole wasn't big enough, and there were some other obstructions, not the least of which was the line of nut plates along the forward upper edge of the spar.

 I was having nightmares that I wouldn't be able to get it in.

 First things first - get the gear leg into the weldment.

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I worked on this guy pretty much non stop for about 2 hours.

 There were a couple of gotchas that were AHA! moments that might save some folks some grief.

 I had enlarged the hole in the floor enough with a file that I knew it would fit ok, but it kept hanging up and not going in. I was stumped until I finally saw two issues.

 One was dumb - I still had the bolt through the upper spar where the spacer goes. The nut is hidden under the flange and I didn't see it.  It was preventing the frame from sliding aft enough.

Once I took that out things improved quite a bit, but it still wouldn't fit tightly enough aginst the side like it was supposed to.

The other issue was a bit harder to see since I was doing all the work hanging over the side with the plane on supports about 16" high.

 The support bracket that is near the center section won't slide between the previously installed floor stiffener and the spar. The stiffener has to be trimmed back a bit so the gear main can slide behind.

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I did that with my Dremel. Once I did that it fit fine. Much relief when that finally happened. After a lot of fussing and more match drilling, here's the final result.

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Aug 11th, 2013 - Continuing with the flap actuator assembly

Sunday night after I got back from flying, I spent the evening going through all the parts getting them ready for priming. I knew Monday was going to be a decent day, so I planned to get out of work right at 5 and run home and prime everything.

 I'd fabbed up all the parts the previous week, so I wanted to start riveting. Flap actuator channel with attach brackets - these will screw to the cabin floor.

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Riveting the F776C plate to the channel. This is to beef up the channel where the motor mounts.

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Working on the F767 attach plate. This will rivet to the flap channel and screw to the F705 bulkhead.

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F767 attach plate riveted in place and nutplates all installed.

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Channel installed in the fuse to make sure it fits and to start test fitting the motor.

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Motor temporarily installed in place to check that it all moves freely and connects properly.

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Van has you set 1/2 travel on the motor, so I rigged up a Rube Goldberg power supply - an old dead UPS (12 volt) battery, hooked up to a battery charger (the dead battery is for ballast). I rigged up the switch (DPDT) into an old peanut butter jar and wired it all up so I could run it up and down and find center (and play a bit).

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Aug 4th, 2013 - Flap actuator, covers and motor

Started on the flap actuator assembly this week. The flaps on my RV are electric.

 There is a gear motor mounted in a compartment that sits vertically between the seats. The motor pushes an arm on a torque arm weldment that has arms which connect to pushrods that are connected to the flaps.

 The torque rod is held in place by 3 bearing blocks made from high density plastic (one on each end near the fuselage sides, and one in the middle) which is both strong and slippery.

The outboard bearing blocks were done months ago during fabrication of the F705 bulkhead.  The center one still needs to be done though.  They supply it with the hole in the middle, but we get to drill it for the mounting holes and cut it in half.

I put blue painters tape on it so I can mark it for drilling.

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So far the best method I've found for drilling (since I don't have a vise for my drill, or a milling machine like Marco), is to clamp it to something else that is vertical to give it more surface area, then clamp the whole thing to the drill table.  I then work my way through it.

It's easy to drill, but the plastic heats very easily with the drilling friction, so it tends to flow out of the way and leave a smaller hole than you really want.  I usually do the best I can, then later when it's cool I'll hit it with the drill again to clean it up.

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Once that was done, I cut it in half.

The next task is to drill the end of the flap actuator rod for a safety wire.  This is to prevent any possibility of the rod end bearing backing out and leaving the flaps in some unfortunate (and unmovable) state.

This was tough - it's a tight fit, and you have to keep away from the nut (which is removed for this shot).

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Once that was done I could work on mounting the flap actuator weldment to the floor and bulkhead.

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Next it was time to fabricate some parts - mostly angle or plates that will be used for mounting the motor in the flap channel.  This is one of them. From Fuselage This shim tube was fun.  It's only 13/32 long - to get it to length I cut it as short as I dared with the band saw, then taped it into a drill bit and squared it off and ground it to length on the bench grinder.

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Sunday afternoon was absolutely gorgeous.  We had a cold front go through, the humidity was bearable, and the temps were in the 70's, so I went flying.  Our usual summer MVFR haze was gone, and you could actually see more than a couple of miles.  What a great day to fly.

KFKN on the way past.

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Sunset passing Lake Drummond.  Inbound on a practice ILS 5 approach.

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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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