Dave’s RV-7A Building Log

I re-worked my electrical plan, identifying how I wanted to route wires through the fuselage. Most wires will travel up through the central tunnel and through the middle holes in F-704. Wiring from the wing will enter the side of the fuselage just aft of the pushtube openings and go through the outermost holes in F-704. By locating the strobe power supply under the pilot-side baggage floor, most of the wires from the tail (elevator trim servo, tail strobe) will go under the floor to the left of the tunnel.

It’s all working out very well. The only unknown is whether there’s enough room in the F-704 holes for all of the wiring going up to the panel.

I also started to work on sizing some of the wiring. I’m still rather confused on how exactly to pick the wire size. House wiring is so much easier, 14 for lights, 12 for outlets, etc.

I decided to install the rudder cables, at least up to the baggage compartment. I’m not sure why I put this off so long. It’s cool having them in place.

I also worked on positioning the rudder cable fairings I made a few days ago (or was that yesterday…). I drilled them to the fuselage, dimpled, and then realized I don’t have enough MK-319-BS rivets. There just isn’t good enough access to use solid rivets, so I’ll order more of the MK’s.

With the canopy set aside for the time being, I started doing a bunch of miscellaneous stuff.

Julie helped me rivet the nutplates to the firewall for the contactors. I had to trim the tab on the master contactor just a tiny bit to get them to fit.

While Julie was in the riveting mood, she also rolled under the fuselage on the creeper and shot the 4 rivets holding in the bellcrank support. Those rivets have been waiting a long time, mainly because I kept forgetting about them. Thanks Jules.

I also made some rudder fairings following Sam’s directions. They turned out pretty good for 20 minutes worth of work.

Going back to the canopy directions, I realized I didn’t attach the handle. I already fabricated the whole thing, except for drilling the hole for the cotter pin at the top. Unfortunately, the screws called out by Van’s were a tiny bit short. I’ll order one size longer and install those instead.

I then started to contemplate wiring. I decided I really needed a plan. I sat down with pencil and paper and drew out a schematic and then a wiring plan for the fuselage. It was a fun exercise, but took literally hours to do. I used info from Aeroelectric, Van’s sample wiring diagram, and various other diagrams that I’ve printed along the way.

Continuing on the canopy, I took some Kerosene and cleaned up any remaining tape residue from around the edges of the plexiglass. Julie helped me place the plexiglass on the frame. I then attached it with screws and nuts starting at the middle of the bow and working my way out and forward along the sides. Turned out mighty fine. The only minor issue is that the front of the plexiglass lifted about 1/8-1/4″ along the front. It’s a common issue, from what I’ve read. I really tried to keep the sides pulled in when I was trimming, but I guess it wasn’t good enough. I’ll just use some clips to hold it down before glassing it in.
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And then it got put back in the guest room, or as I call it, the aircraft part room.

I also messed around with the firewall a little bit.

I usually don’t get much done on a Friday evening, but Julie wanted to move her car back into the garage. That meant finishing up the canopy, or at least getting the plexiglass installed so I could put the whole thing back in the guest room.

I took the canopy frame outside and touched up the paint on the inside where it got scuffed up from riveting. I also painted the glare shield with the Ultra-flat Krylon, which turned out excellent. You can see how the overhead light is reflecting off the bare aluminum, but not at all off the paint.
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I stopped by Sears at lunch time to pick up a mandrel for the funky hole saw, but the check-out line was moving verrrry slowly. And the mandrel is $20. And I’d rather use a punch anyway. I checked out Spruce for Greenlee punches–$100 each, ouch! I looked on Ebay and found a “2 inch punch” for $6. I bid on it and later found out the punch is actually intended for a 2″ conduit and produces a 2-3/8″ hole. Bummer. A -6 builder in the area emailed me and said he might be able to borrow a punch from work. That would be excellent, since I really only need the punch for a few minutes.

A neighbor stopped by with his son and daughter to check on the plane progress. His 6 year old son was totally into the plane, asking all sorts of questions and asking if he could have a ride when it’s finished. Nothing like a little youthful enthusiasm to re-energize me on the project. The fuselage is kind of a mess with tools and aluminum chips everywhere. After they left, I did some clean up in there. I’m sure I’ll create more chips, but it’s nice to get the thing vacuumed out.

I mounted my fabricated ELT frame to the baggage ribs with some LP4-3 pop rivets. The access wasn’t great, but I got it in there. The ELT rattles a tiny bit in its mount, so I might shim it a bit. Otherwise, it looks great.

I started to think about how I want to run the wire for the ELT remote panel. A few builders have said they don’t like running wires up the central tunnel and through the center spar because of possible interference with the pitch/roll control mechanism. (After re-reading Dan’s log, the problem is actually with the wiring holes right at the front edge of the rib–not the tunnel.) I decided to mount the control sticks to see exactly how much space they occupy.

It took a while to get the bolts and washers into the very tight spaces. I used the digital level to sort of align the two sticks to each other while installing the lower connecting rod. It’s cool to have the sticks in there again. Of course after I got everything perfectly aligned, I realized I’ll have to remove the pilot stick to drill a hole for wiring.

I picked up a new 2″ hole saw at Sears, since the old one is just not able to cut through the steel battery box. Wouldn’t you know it has a different type of mandrel. Frustrating.

Instead I laid out the rest of the holes that need to go through the firewall. There’s the cabin heat, fuel line, throttle, mixture, prop control, and some sort of line for the manifold pressure sensor. Using the dimensions from the plans in Van’s firewall forward kit, I carefully marked the location for each hole on the firewall. I’m going to do a little more online research before I actually drill the holes.

Another thing I did was to wash the canopy frame. I need to spray some touch up interior paint on the inside, and I picked up some “ultra-flat” black Krylon paint for the glare shield. The easiest way to prep for painting it to just wash down the frame outside with Dawn and rinse really well.

The last thing I did for the day was to drill the ELT mount to the baggage ribs and debur. I was putting off doing that until I was absolutely certain that’s where I wanted it. I was 99% sure, so I drilled it. This project would go so much faster if I didn’t have to double and triple think about every little detail. However, it’s easier to think about something three times than to do it wrong and have to fix it.

I’m skipping around a bit, mainly because the other parts are all waiting for something. I decided to work on mounting the battery box and contactors to the firewall. There are a few rivets that need to be drilled out of the firewall and then enlarged for AN4 bolts. You have to be very careful because some of the drilled out rivets become the bolt hole, but some are just a rivet hole for a nutplate. Drilling through the stainless firewall is not fun. This part would definitely be much easier to do before the firewall is assembled.

I managed to do all of the drilling, dimpling and countersinking. Now I just need Julie to help me buck the rivets to attach the nutplates.

I pulled out the parts for the battery box and started working on them. I almost immediately screwed up the battery tie-down bar by drilling the lightening holes too close together. I added a new one to my “order from Vans” list.

I then drilled the side angles to the battery box, using a piece of .020 under the right hand side to simulate the firewall recess, per the note on the plans. I deburred the holes (never fun with steel) and dimpled the holes for flush head rivets on the inside.

I started to cut the lightening holes in the battery box with a hole saw, but it quickly dulled. I need to get a better hole saw. It’s quite a mess. I’m now wishing I hadn’t bothered with the lightening holes.

Steve and I went over to Spokane to help our friend Jeff with his 7A project. We spent most of Saturday joining his center section and tail section, attaching the side skins, drilling the longerons, and mounting the firewall. I think that all took me about 2 weeks when I did it. Not a bad day’s work. It definitely helps having extra hands around.

When I returned on Sunday I had a little time in the afternoon to fabricate the strips that back up the screws holding the rear window to the top skin. I made 4 separate strips out of the extra material from the wing walk doublers. I also dimpled the top skin.