Dave’s RV-7A Building Log

The parts I needed finally arrived from SteinAir. I was able to hook up the master contactor to the main bus with some #6 wire. I also wired the master switch to the contactor and ground. Flip the switch and bingo. The contactor energizes and juice is flowing. I have to be careful now that I have +12V running around the plane. For example, I don’t want to accidentally fire the starter. I think I’ll leave out that fuse until I get to the hangar.

So to recap, I have 1/2 of one switch wired so far and I have 10.5 to go. The others should go quicker, though.

A side note on comments. I’ve decided to disable comments on posts. 99.9% of it was spam, and I’m tired of dealing with it. If you have a comment on a post, just shoot me an email using the link in the right sidebar.

I installed a 3/4″ fitting from EPM.AV in the firewall for passing wires through. I should be more fire-proof than just a snap bushing and RTV. It was a bit difficult to install. Drilling through stainless steel is never fun. And it also doesn’t provide any anti-chafe protection for the wires. Hopefully there will be enough room after wiring to jam some firesleeve in there.

I was originally planning on using a 3/4″ fitting for the engine sensor wires and 1/2″ fitting for everything else. However, it quickly became obvious that 1/2″ was not big enough for anything other than a wire or two. I’ll return that one for another 3/4″.

With the fitting in place, I can now run wires through the firewall. I started by running wires for the starter contactor. The electrical parts I ordered from SteinAir 2 weeks ago should finally arrive tomorrow so I can hook up the battery and finally start turning stuff on.

I spent most of today down at the hangar getting it tricked out. I’m going to hire somebody to put in drywall, but wanted to add a few outlets first. Running metal-clad wire is not fun, but it’s a commercial building. I also spent a while down at the pool enjoying the sunshine with Adele on her last day of summer vacation.

I found a little time to work on the plane. I figured out the best location for mounting the fuse blocks. I drilled #12 holes and temporarily put some bolts in there. I’ll order some screws that have a smaller head for permanently mounting them.

I didn’t get as much done over the 3-day Labor Day weekend as I had hoped, but I had some excellent time away from the project instead.

I guess some builders simply use star washers to keep their switches from rotating, but I like the keyway washers. I made backing strips from .063 sheet with dimensions from Aeroelectric. It worked perfectly. On the second strip I made one minor change that worked better. Instead of drilling a 1/8″ hole for the keyway washer, I used a #36 drill bit. It’s just big enough and doesn’t allow the switch to turn as much.

I temporarily mounted the switches so I can wire them up. I also made labels, so I don’t get confused. I like the blue tape look. Maybe I’ll just use that for the final panel (not).

I also ran the headphone and mic wires for pilot and copilot. I debated quite a bit on where to locate the jacks. The place I was originally going to use will be covered by my fancy side panels. Looking through the Aircraft Spruce catalog, I found some flush-mount housings that will work out great. The jacks will be right under the arm rest and just aft of the seat.

I ran the pitch servo wire back through the plane. It was a little difficult to get it through the F-704. I used some tubing to keep the pins together. There’s a little slack in the wire, which is perfect. Better a little slack than not enough.

When I had Ross make the panel, he made the hole for the starter switch undersized. I wasn’t sure what size hole it needed. Turns out it’s the same as the other switches. Looks pretty cool.

I also ran more of the wires up and down through the shelf. It’s starting to be an actual wire bundle.

All of the plane’s wiring will funnel to two bundles along either side of the firewall recess and go through two holes in the shelf. I cut those holes and started feeding wires through. I also cut apart some more of the Stark harness and fed those wires around. In order to feed the autopilot wires through the small holes, I had to remove the DB-9 connectors. I wrote down which color was in which spot and then carefully removed the pins.

I also did some more thinking on where to put the holes in the firewall. I think I’ll have one hole off to the right for the engine sensors and one dead center near the top for everything else (alternator, P-mag, main feed, etc.).

It’s a great feeling to finally be jumping into the wiring. Now I just have a ton of wires to run back and forth.

August was a pretty productive month. I put in more hours than I have in over a year, and I’ve gotten the panel well on its way.

Adele’s soccer jamboree yesterday kept me away from the project. However, my order from B&C Specialty Products arrived, a large fuse block, 6 AWG wire, and some switches. They sent out the order on the same day I placed it! Wish I could say the same thing about SteinAir. It took them 4 business days just to ship my order. As soon as that gets here, I can hook up the battery to the fuse blocks and start powering stuff up.

I spent just a little time tonight messing around with electrical stuff. I gathered up all the switches and identified which one was going where. I’ve got one weird switch that I thought was for the flaps. I spent a bunch of time trying to figure it out, but turns out I have a different switch for the flaps. I have no idea what that other one is for.

I also started unrolling the Stark wiring harness and separating out the power and ground leads. So far the harness still looks about perfect.

One other item of note today. I called Advanced Flight Systems to get an update on shipping out the AF-3400 EFIS and EMS. So far I keep getting slipped deadlines. I’d really like to get the engine sensor harness so I can get the FWF finished up. They said 2 more weeks for that. And the units themselves should start shipping to the initial customers in 4-6 weeks. I should be near the top of the list as I placed my order right after Sun ‘n Fun. If I can get them by mid-October, I’ll still be in good shape. Much beyond that is going to start affecting the first flight date.

I wasn’t feeling good, so I didn’t do too much. I made cables for the engine ground and negative battery cable. They both terminate at the ground block on the firewall. Steve’s crimper does an awesome job on the 2 AWG terminals. I put it on the floor and use significant weight to push the handle home. I also cut the starter cable, but haven’t decided exactly how I’m going to route it–probably along the right side of the engine inside of the intake tubes.

I finished up the stick wiring. Now that I knew the trick for the Molex Microfit 3.0 connectors, it went really smoothly. I followed my sketched out drawing carefully, stripping wires and crimping pins. The stick, relays, indicators, and servos all connect here with the Molex connectors. I can easily remove and replace any component. Looks a little messy now–a wiring job only a builder could appreciate. I’ll get it all wire-tied and pretty as soon as I test the direction of the elevator servo.

I trial fitted one of the AN3-60 bolts to the brake pedals a few days ago. Figured it should do the rest before riveting in the subpanel structure. It wasn’t fun leaning over the side of the fuselage and messing with the bolts in a tight space, but I got it done.

I originally ordered 2 Hartwell latches from Wicks and got two different types. One looked like it would work well for mounting in fiberglass and the other aluminum sheet. I asked them to send a matched set, and unfortunately didn’t specify which I wanted. Of course I got the aluminum sheet ones. So I placed another order for a matched set this time and nicely asked for ones that have the latches approx 0.1″ proud of the mounting plate. Bingo! These look perfect. I did a tiny bit more filing to improve the fit and then drilled them to the oil door. I’ll need to use some washers or epoxy filler or something before riveting so the latches will follow the curve correctly. Still need to figure that out.

For some reason, Julie wanted a picture of the Guest Room, rechristened the Wing Room. The picture doesn’t even do it justice. The wings, flaps, and ailerons are visible, but the empennage is tucked way in the back. The canopy is off to the right and all the wheel pants are behind that. Plus all the stuff that would normally be in the garage is packed in here. I promise it will all go to the hangar soon, Julie.

I messed with the stick wiring some more. I was swearing a good deal at the Molex Microfit 3.0 connectors that I decided to try. I couldn’t get the pins to sit right. I was shoving them in, they were going in too far, bending the tabs, getting stuck, etc. I was really getting frustrated and burning through the fairly expensive pins.

I was about to go back to the DB-9 style pins, when I finally figured out my issue. The pins insert into the connector in one direction and one direction only. When it’s all lined up right, they just slide right in and click very subtley. Now that I know what’s going on, I think I have the wrong extraction tool, because I can’t see how it could depress the tabs on both sides of the pin at the same time. But with the right tool, the pins should come right back out again. That’ll be handy for swapping wires if servos are running backward.

Now that I’m on the right track, I should be able to cruise on the stick wiring.