Dave’s RV-7A Building Log

It’s the time of year when Julie wants to put the top down on the convertible, which means taking the hard top off. The soft top does not like to be outside. It’s wet in the morning, so you can’t put it down. And it’s nice to just pull into the garge in the evening with the top down and leave it down.

Thus, we started a massive day-long clean-up effort around the house involving smashing up the old picture window, picking up various wood and debris around the house, borrowing my in-laws truck, and finally a 1/3 ton trip to the dump. I spent a huge amount of time cleaning everything off the shelves, dusting everything, moving the shelves into the spare room (aka the wing room), and transporting all the various parts into there. There’s a ton more room in the garage now. As soon as I’m done messing with the canopy, the car will fit again.

I mixed up some really stick epoxy with microlight filler and black dye. I cut a corner off a zip-lock bag and used that like I was decorating a cake. I squirted the filler into the crack between the plexiglass and metal. I used a gloved finger to smooth it out until it looked really good. Well eventhough I had the epoxy really mixed up stiff, it still sagged a little bit. I mit apply a bit more filler before starting with the fiberglass.

Did various stuff on the plane today including connecting part of the cabin heat system, from the intake to the muff. I was going to hook the muff to the cabin heat selector, but it looks like it’ll be in the way of connecting up the mixture control cable.

For some reason, I didn’t paint the F-704 bulkhead when I touched up the paint in the cabin a while back. Not sure why. It doesn’t matter too much as I just ordered interior side panels. I decided to mask it off and paint it anyway.

I pulled out the canopy in order to work on the fairing at the front. It’s one of those things that I left unti “later.” Might as well get it done. I could actually completely finish the canopy. That would be nice. It seems like everything is partially finished.

I did the DanC trick of using some small tabs to hold down the canopy. My canopy ended up popping up a bit when I secured the sides. The clips held it down partially. I’ll fill the rest with epoxy.

I masked off a line along the plexiglass that looked good. I did a combination of using a 4″ radius (not 4″ diameter as the instructions indicate) cardboard disk to visual the fairing shape, measuring with a ruler, and just eyeballing a smooth curve. It turned out pretty good. I masked off the metal below as well just to minimize the mess. I sanded the metal and plexi with some 60 grit sandpaper. It’s tough scratching up something I spent so long trying to look perfect. The picture shows an intermediate step where I was using chunks of masking tape to mark the line.

I didn’t do any building today, but I did order leather seats for the plane from Classic Aero Designs. They make two different models seats now. I went for the fancier seat, although without the headrests. I think those headrests will interfere too much with access to the baggage area. In addition to the seats, I also ordered their side panel kit and carpets. I ordered everything in a dark gray, which will go nicely with the harnesses. It was a big order, but I might as well make the plane look nice. They are booked out about 13 weeks. I should receive everything some time in August.

I spent the evening undoing the work from yesterday and redoing it at the front of the baffles. I made a patch for the hole in the back of the baffles. It’s not a structural area, so the patch will be fine. I really don’t want to redo the baffles at this point. Riveting in there would have been nearly impossible, so I used (gasp) blind rivets. I used some of the sealed rivets that I had left over from the fuel tank. I also put some RTV under the patch to help seal it.

I cut a new hole in the right baffle floor and clecoed the flange in place with some RTV. I’ll let that set up before I rivet.

I moved the cabin heat muff back to the #1 exhaust pipe again. It’s going to be a tight fit to get all of the hose routed through there.

I bought a 2″ hole saw a while back, but it has the “quick release” style mandrel. I finally picked one of those up on the way home. I used the hole saw to cut a hole in the back right baffle wall. I then used the flange as a template to drill the holes. It’s going to be tricky doing the riveting in there. I’d prefer not to remove the baffles, but I might have to.

After deburring everything, I then used some high-temp RTV to seal the flange to the baffle. At this point I looked at the plans and realized I was supposed to put the screen in there as well. I took off the flange, re-applied more RTV, and clecoed it back on with the screen in place. I decided to wait on riveting until the RTV set up.

I then worked on getting the cabin heat muff secured. I tightened down the nuts that hold the end caps in place and put the band clamps around the whole thing. It’s definitely cramped on this section of exhaust pipe and the end caps aren’t straight, but it works.

It was around this point that I started to think about this location more. Having the slip joint inside the heat muff is not a good thing. If for some reason the exhaust gases were to leak out of the joint, they’d go right into the cabin. Not good. I posted a message on the VAF forum to confirm that it could be a concern. Since I didn’t want the flange permanently installed to the baffle if I decide to move it, I unclecoed it from the baffle. I set the flange down on some wax paper so the RTV could still hold the screen in place. Looks like I’ll be making a patch for the rear baffle wall. Oh well.

For lack of something better to do, I messed around with the control cable linkages. Whoever put the throttle/mixture cable kit together at Vans was asleep on the job. The plans call for different hardware than what is included in the kit. I ended up ordering some extra large area washers. They arrived a while ago, but I hadn’t installed them yet. I looked over the prop, throttle, and mixture links and installed the proper washers. I tightened down the nuts and added cotters pins. On second thought, I’ll probably have to remove the pins. I’ll need to be able to install the link onto the end of the control cable. These pictures are prop, mixture, and throttle, in that order.

I also messed around with some possible configurations of the breather tube. With the oil filter adapter in the way, I can’t install the breather tube per the plans. I’ll have to develop a different routing.

I have several tasks that are waiting on various parts. I’ll place some orders so I can move forward on the rest of the engine stuff.

I stopped my Sears earlier in the day and picked up a few socket wrench gizmos that I thought would work on the hard to reach exhaust pipe nuts. I ended up using a 1/2″ 6-point swivel socket and 6″ extension bar. I used the one for a 1/4″ socket wrench (and then a 3/8-1/4″ adapter since the torque wrench is 3/8″) only because Sears didn’t have the 3/8″ in stock. It probably would have worked as well. I tightened up all the exhaust pipe nuts to 120 in-lb.

I dinked around a little bit with the cabin heat muff and looked at a few web sites to see where people tap off the aft right baffle wall. I also had trouble tracking down my 2″ hole saw. At that point I wasn’t feeling so hot for some reason, so I worked on the computer for a while.

I used Excel to make a list of everything that’s left to do on the plane. I’m sure I left out 1/4 of the tasks, but I’ll keep adding to it as necessary and crossing things off as I get them done. I thought it would be depressing to see how long the list is, but it’s not bad. It helps to condense some items like “Wiring”. I’ll expand those once I start working on them.

Today was an absolutely stellar day, sunny and 70 degrees. It felt like summer. Consequently, I spent most of the day outside washing the cars, hanging out in the back yard, and riding bikes with Adele and the dog.

I did find time to work on the exhaust hangers. Those things are a pain, mainly because of the limited access behind the engine and the funky spring clamps that go around the exhaust pipes. I positioned the pipes where I wanted them. I then used some cleco side clamps and/or needle nose vise grips to hold the two clamps around the pipes. From there I measured distances, cut the little pipe thingys, and cut the rubber hose. I also flared the ends of the tubes as Dan showed on his site to hopefully keep them from slipping off. Installing everything took quite a while, because a few of the bolts I could only turn one flat at a time.

The hangers attach to the sump. These pictures show which bolt I used on the left and right sides, respectively.

There was one spot I had to do a little filing on the sump in order for the hanger tab to have a flat spot to sit on.

I’ve noticed that almost everyone puts the cabin heat muff on the back exhaust pipe rather than the front, and pulls the air off the back baffle wall. This also makes a lot of sense to me. The routing of the SCAT tubing is much, much easier. I had previously partially installed the muff on the front exhaust pipe, so I removed that and started installing it on the rear pipe.

Last night was the 4th grade competition for the math team. They did great. My duties as Math Team coach are almost done.

I didn’t get too much done on the plane today. Instead I took my first RV ride with John Adams. His plane looks great. I especially like the simple but noticeable paint scheme.

We flew up to Arlington and grabbed a bite at the Taildragger. Jim Piavis met us up there in his Boredom Fighter.
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The Black Jack Squandron was practicing, and I got to see them land in formation. Pictures cannot capture how cool it is to see 9 planes break from the overhead one after another. And yet I keep trying to photograph it.

After lunch, we hung around Jim for a little bit. It was challenging for John to slow down to Jim’s speed. It’s tough taking shots in the tight confines of an RV, especially when the plane is bouncing all over the place. I have a new appreciation of Ed Hicks pictures. Here’s a couple that turned out pretty good.

The RV is a great flying machine. It’s fast and incredibly responsive like a sports car. I definitely made the right choice of plane to build. Thanks John for the ride!!

After I got home, I decided to pull the plane out into the driveway and do a thorough sweeping of the garage. Plenty of neighbors slowed down and gawked at the odd sight.

Jeff Harrang and his wife Carol, potential RV builders, emailed me earlier in the week and dropped by to check out the project.

After all of that, I spent a little bit of time verifying the lengths of the throttle, mixture, and prop cables. I have the regular venier controls that came with the firewall forward kit. I’m going to return them to Vans and order throttle quadrant-compatible cables, but I wanted to double check the lengths first. They all look good.

Took a night off for the Seattle Eastside EAA 1440 (provisional) Chapter meeting. And another night off to drink beer and celebrate my birthday.

Tonight I installed the alternator belt. I grabbed a 7355 and 7360 from Carquest. Their belts are actually made by Gates. The 7355 ended up working out well. It’s a tight fit, but the belt might stretch a bit after the engine is run. There’s about 1/4″ between the alternator and prop oil line. If the belt is too long the alternator will rub against the FAB. There’s not much leeway on either side.

Another thing that took some time was fixing one of the mounting bolts. There weren’t any threads showing above the lock nut. I removed the alternator and grinded down the mounting bushing. That plus using a thin washer did the trick.

I tensioned the belt so that about 12 ft-lbs of torque applied to the alternator pulley stud caused the belt to just slip while the starter ring gear was held in place. I read on the forum that’s the best way to set the tension.

Saftey wiring the alternator bolts was a pain. I did the inboard bolt with the starter ring gear off, but then screwed up the outboard bolt. I wrapped the wire the wrong way. I didn’t want to remove the perfectly tensioned bolt, so I re-did the safety wire with the ring gear in place. It’s much more difficult, but doable. The second time looked much better anyway.

I also sanded down the filler I put on the ramps on the top cowl. The filler is really easy to sand. It turned out good enough. I’ll perfect my filling skills around the inlets of the cowl where it will be more noticeable.

I also installed a few various things around the engine, the fuel pressure line, and the plugs for the extra holes on the sender manifold. It’s cool installing all of these various gizmos. There are fewer and fewer parts on the shelves.