Dave’s RV-7A Building Log

The engine arrived!! I was expecting all sort of wresting with a heavy crate, but it was a non-event. The driver just wheeled the crate into my garage with a pallet jack. It arrived without so much as a scratch. There was some water inside the plastic covering the engine. It’s a good thing they use it. The engine appeared dry.

A small tip for others getting a Mattituck engine: The top of the crate can be removed by unscrewing two bolts. I ended up tearing it apart piece by piece before I discovered that.

Several views of the engine.

There was also a small box of goodies, including a Lycoming engine manual. They provided the fuel line from the pump to the fuel servo, which was also in the Van’s firewall forward kit.

I spent quite a bit of time looking around the engine, indentifying ports, checking out the fuel servo, etc. I was surprised to see the alternator. I wasn’t aware that the engine came with one. It’s a Mitsubishi, but looks much larger than the Nippon Denso alternator I have from Vans. I’m wondering if it would fit inside the cowl. (Edit 12/1/05: Mahlon confirmed that the alternator was a mistake. He said if I can use it, to keep it with their compliments. Nice.)

Another thing I noticed is that with the oil filter adapter that Mattituck uses, one of the ports for the oil cooler is behind the oil filter. It looks like I’ll have to remove the oil filter and use a 45 degree fitting. Not a big deal.

There’s a port on the side of the fuel distribution spider that I’m not sure about. I didn’t think there would be a purge line, but I’m not sure what else it could be. (Edit 12/1/05: Mahlon said the port is for metered pressure, something I most likely will not need. I just need to plug it.)

I wish the P-mags had shown up in time for Mattituck to install them. It’s going to take me a while to figure out installing, wiring, and timing them. Plus I would feel much better knowing that the engine was run successfully with them installed.

The engine didn’t have dessicant plugs in it. I’m not sure if they’re needed. (Edit 12/1/05: Mahlon said these really aren’t needed for my engine. The cylinders won’t rust.)

These are all questions that I’ll ask Mahlon about.

I spent a little bit of time finishing up the battery box. I had forgotten to put on two nut plates. The engine mount was in the way of installing them. Instead of removing the engine mount (which is still just temporarily mounted anyway), I removed the battery box, installed the nut plates, and installing the box.

I ordered an Odyssey 680 battery and Battery Tender Jr. charger from Sunn Batteries a few weeks ago, and they showed up today. The output of the battery charger is 750 mA and the manual for the battery says that at least a 2 A charger is needed to charge the battery. That made me a little worried. I checked the voltage on the battery and it was 12.61. The battery manual said to charge it if it was under 12.65, so that’s what I did. I put the battery in the box on the firewall and hooked up the charger leads. The charger had two options for battery hook up, either clamps or what looks like 5/16″ ring terminals. The ring terminals worked perfectly. The charger indicated “charging” for about a minute and then went to trickle mode. During the charging cycle it very gradually increased voltage from 13.2 up to about 14.4 volts. I disconnected the charger and checked the battery voltage again. It was right about 12.8, which works great. I think the charger is going to work just fine for topping off the battery occasionally as I use it for electrical testing.

I hadn’t completely finished the battery box yet. I was waiting for the battery to arrive before making the spacers for the hold down bar. I went ahead and cut those to 15/16″ and worked on trimming them down to fit. I didn’t get too far as the “March of the Penguins” DVD showed up from Netflix, and I was eager to watch it.

The coax stripper showed up in the mail. It wasn’t set up perfectly for the RG400. It kept cutting the center conductor. I adjusted the blades until it worked pretty good. I attached aonnector on to the end of the transponder coax and attached it to the antenna. Pretty easy stuff when you have the right tools.

I next finished drilling the engine mount to the firewall. I made a couple of spacers for the bottom holes out of .063 using the fly cutter. They turned out very nice.

And the last task was to install the brake mount on the right gear leg. This one went much easier. The holes on the brake flange lined up better, and I knew what I was doing this time.

Still no engine. It should be here soon.

Yesterday I spent most of the day down at the Auburn Airport helping Jim mount the wings to his fuselage and drill the rear spar. It was great to see that process first hand. That’ll help when I do mine.

Today, my friend Steve stopped by to help out with the project. We made some major progress. We started by riveting in the steps. Julie usually helps me with riveting, but she doesn’t really like the 3X gun very well. Steve and I hammered these out in no time. Access is a little tricky. I ended up using 3 different bucking bars, and messed up one of the shop heads.

Next up was the engine mount. We figured out a really clever way of handling this. First we verified that the holes in the mount line up pretty well with the starter holes in the firewall. They are each off by maybe 1 mm. I drilled the two top holes in the firewall to #12 and then used a long AN3 bolt with a large washer to hold the mount in place temporarily. We shifted the mount around until it lined up with the holes as good as possible, sort of spreading out the error (which wasn’t much). I then drilled the holes in the bottom to full size, and then the top holes, inserting the official bolts as we went along. It worked out great. It’s very cool to have the mount drilled to the fuselage.

I didn’t drill the lower two holes yet. I figured I could do those on my own. I’ll need probably a .063 spacer in there as the mount sits off the firewall a tiny bit as I’ve seen on other builder logs.

Next up was messing with the brake mounts for the gear legs. The instructions and plans for these things are not clear. Steve and I messed around with it for a while and mostly figured out how it was supposed to go together. Steve had to take off, so I browsed a few builder logs and got an even better idea of how it was supposed to go together. Matthew Brandes’ site had some very helpful pictures.

It seemed like every part of this thing didn’t fit well. I had to use a Dremel drum sander to clean up the inside of the brake flange to get it to fit on the axle. The hole through the flange and axle had to be reamed out. And the holes in my brake flange did not line up well with the Cleaveland part. I had to ream out all of those holes as well, but finally got everything in place. For one side. Hopefully the other side goes smoother.

I started off the day by mounting the transponder antennas. I decided that just aft of the bellcrank was a good spot. I could mount it right on the centerline and it would be out of the way of the push tubes. I printed out Trutrak’s diagram for mounting the pitch servo to make sure I was far enough aft of that. One other thing I did was trim off the edges of the doubler where I drilled all of the holes. Noone else seems to attach the doubler to the skin with rivets and it seemed like overkill to me as well. I cleaned off the little bit of primer on the skin to make sure the antenna had a good connection with ground. I ran some coax back there and was about to install the terminal on it, when I realized I needed a 3-blade coax stripper instead of the 2-blade that I have. I ordered one on Ebay for $11. I could probably cut it with a utility knife, but the coax strippers are much easier to use.

The other thing I worked on was cutting access holes in the baggage floor for the ELT and strobe power supply. I drilled holes in the corners, cut between them with a jigsaw using a fine-toothed blade (which worked really well), and filed up to the line. After doing all of that on one of them, I did a trial fit. I wasn’t happy with the shape of the hole. I was planning on leaving some extra material on the inboard side for attaching the hinge, but forgot about that. I might end up ordering new panels.

I spent some more time on the antennas doublers, laying out and drilling holes around the perimeter for attaching them to the fuselage skin.

I’m also trying to figure out where to install them. I’d like the transponder back aways. I don’t really want it right under my rear end. I was also trying to put the COM antenna somewhere where I could reach the connector in case I wanted to attach a handheld to it. I’m thinking of one of these two spots just forward of the F-704 on the pilot side. One has the potential of getting kicked and the other might put the antenna in the shadow of the gear leg.

I didn’t feel like attacking anything too big. I just made some doublers for the com and transponder antennas.

Adele was over at her grandma’s house, Julie was working late, and I already walked the dog. That all adds up to quality shop time.

My order from Vans arrived with various little things I’ve been waiting for. I installed the parking brake valve with the long screws I ordered and connected the flexible line between the valve and the pilot brakes. The cockpit side of the brake system is now done including co-pilot brakes and parking brake.

I also received some fittings that I needed for the transducer manifold. I installed those with some teflon paste (oil pressure) and EZ-lube (fuel pressure) and temporarily bolted it to the firewall. I still need to rivet the upper ribs to the firewall, so I’ll have to remove it eventually.

I then turned to the trim wiring. After spending tons of time thinking about this, I finally came up with a plan on wiring it all together. The first step was to attach DB-9 connectors to the relays. These connectors are very cool. I slipped some shrink-wrap over the wires, stripped off 1/4 from the end of each, and then crimped on the sockets. I heated up the shrink-wrap over the end of the sockets to act as a stress relief and then slipped the sockets into the connector body, writing down which wire was in which hole. The final step was to shrink the wrap around the whole bundle. It took a bit of time, but looks very professional and sturdy.

I spent a bit more time thinking about the other components of the trim system. The trim is definitely the most complicated system on the plane outside of the avionics. I’m starting to wish I had just gone with manual trim.

Another item that needs to go on the firewall in the ground block. I cut a piece of .063 sheet to size to fit 3 of the ground tab clusters I bought from SteinAir. Each has 10 tabs on it for a total of 30 tabs. That should be enough. I countersunk the back of the sheet and then rivets the tab clusters to the sheet. Looks simple. I just need to figure out the bolt size I need and then attach it to the firewall above the battery. Forgot to mention that I tested the resistance between various parts of the ground block, and it was all below the level that my multimeter can measure.

I got a ton of little items done today. I started off by riveting the parking brake reinforcement in place and adjusting the brake lines to fit. I had to trim the left line a little bit. I also used compressed air to blow out the lines before installing them. I’m waiting for some screws from Vans, so the valve itself is just clecoed in place. In the picture, you can see a little tab sticking out at the top of the reinforcement. That’s where I’ll attach an adle clamp for the cable. I probably put way too much thought into this thing, but it should work out pretty slick.

I also used some pop rivets to attach the rudder cable fairings. It’s impossible to buck these.

While I was working on the tail, I riveted and bolted the elevator up-stop in place and riveted the rudder stops.

I drilled out the holes for the pressure manifold, but couldn’t mount it because I have some fittings on order that I “borrowed” for the parking brake.

Next next thing to figure out was how much to trim the sticks. The best way to determine that was to sit in the cockpit and try them out. I had Julie take a couple of goofy pictures while I was in there. The cockpit is starting to feel real with the sticks in place and the panel mock-up. There sure isn’t much side-to-side shoulder room, and I’m not a big guy.

I verified that the seat backs will clear the canopy frame just fine. This was a problem that Dan ran into, but Vans must have fixed it in the plans.

I decided to trim 2″ off each stick. This is about how much the grips add to the height, so I’m really not changing the design at all. After that I drilled a hole in the front of the stick near the pivot point for the wires to exit. Having the wires exit at the bottom makes them move around way too much. I put a small snap bushing in the hole and put some shrink wrap around the wires. I also tweaked the pilot pivot point a bit so that the bolt tightens down on the bushing and not on the stick weldment. I mounted everything back in the plane. The wire is going to work out great.

Of course the stick hits the bottom of the panel by about 1/2″. I’m not sure if that’s a problem or not. I don’t really want to disassemble everything again.

I also spilled about a cup of cutting oil on the floor in the process of drilling the stick. Fun (not). It was of course the one time that I got lazy and decided not to put the cap on the oil.