Dave’s RV-7A Building Log

I looked over the instructions planning what I was going to do for the weekend. As part of the service bulletin on the cabin frame attachment, Van’s sent a whole new set of instructions. I’m 3/4 through the fuselage instructions, so I’m not just going to switch over. Not helpful. On top of that, they altered the width or formatting or something. It was impossible to tell what parts had been updated. Really not helpful. It would have been nice if they had put in change bars, a standard feature in Word. I looked at the section on the cabin frame installation, and it had definitely been changed. I cut out that part and taped it on top of my existing instructions.

In order to get an accurate measurement of the fuselage width, I decided I should finish riveting the few things on the fuselage that I’ve been putting off. Tonight I managed to rivet the 705G in place. I was able to squeeze all but the outboard two rivets, which I solo bucked no problem. A couple of the rivets needed to be in between two sizes that I had, so I used the Scotchbrite wheel to grind it down a bit. Only took about 5 seconds per rivet.

Before and after Adele’s final soccer game of the season (0-0 tie), I found time to prep and prime some of the cabin frame parts.

I finally got in a good work session tonight and finished up the cabin frame countersinking. I moved on to deburring it and will hopefully prime it tomorrow in preparation for assembly.

I also worked a little bit on repairing my toy helicopter. This thing is a clever bit of engineering. It’s not anywhere near as maneuverable as the RC helicopters costing hundreds of dollars, but for $70 it’s a heck of a lot of fun. It’s called a Blade Runner. The twin counter-rotating blades make the thing pretty stable. It uses the landing gear as an antenna, and the little wire from the PC board broke. I soldered on a new one. Of course I used some aircraft wire to fix it.

Speaking of wire, I received the basic wiring kit from Stein a few days back. I’ve talked to Stein a few times on the phone, and he’s a heck of a nice guy. His business on the other hand needs some help. My first order was lost. My follow up phone call was ignored. I ordered the kit again directly with Stein (again). One thing was left off the order and some parts were missing. He’s got good stuff at good prices, though.

Another unproductive building day due to a training session for Adele’s swim team, but I got through most of the cabin frame countersinking. I figured out a handy way to secure the parts for countersinking.

I spent most of the evening helping out at Adele’s swim team meet, but spent a little time starting the long process of countersinking the cabin frame.

I finally finished the cabin frame drilling today. I placed the frame carefully against a straight edge and measured the height. Using the band saw I trimmed off just a tiny bit from each leg to get it to the correct height. I took the parts outside for deburring to keep Julie company while she worked on the brick patio.

It’s been kind of a low-productivity week on the plane. Other things have taken priority.

I managed to do some more drilling on the cabin frame today. I found out it’s much easier to pilot drill the frame parts to #40 and then assembly the thing for drilling to #30. I got about half way through the drilling.

Yesterday was Julie’s birthday, so I took the night off from the project.

Tonight I worked on drilling the aft cabin frame sections to the inner strap. I had a hard time getting the strap to nest nicely inside the bend of the frame. I kept using the Scotchbrite wheel to round down the corner, but it just wasn’t removing enough material. I finally just used the belt sander on it. That worked.

I spent way too much time trying to lay out the drill pattern with rulers, fractions, and a calculator. I finally figured out an easy way to do it. I marked where I wanted the holes to start and end on the cabin frame. Then I laid some tape along where I wanted the holes and marked the start and end points on the tape. I peeled off the tape and put it on a flat surface. Using the rivet fan, I marked out 19 evenly spaced holes. And finally, I put the tape back on the frame and transferred the marks to it. I was able to use the tape on both sides of the aft half of the cabin frame, and should also be able to use it on the front half. Easy.

Using lots of clamps and the long #30 drill bit, I drilled through the frame into the strap. It would have worked better to pre-drill the frame to #40 and then drill the frame and strap together to #30. I’ll do that for the remainder of the frame. This thing sure has a lot of holes in it.

I carefully measured the width of the fuselage at the cabin frame, which turned out to be 42-5/8″. Allowing for the 3/16″ thick angle on each side meant the cabin frame needed to be 42-1/4″ wide. I used the belt sander to trim just a tiny bit from the center joint. I clamped everything down and drilled the joint plate to the frame using the location called out on the plans (thanks Matthew). I was going to drill the strap next, but I needed to round the corner of it first. I didn’t feel like firing up the grinder.

Instead, I pulled out the panel and sub panel and clecoed that together. It looks very cool. Now I just need to fill that panel with $$.

There were just a few parts left on the shelves from the fuselage kit, so I tried to place some of the items. I tried fitting the two covers that go on the front of the F-704 and figured out that I riveted on the two outboard floor stiffeners in the wrong orientation. I can’t believe I did that. Now I need to figure out if it really matters.

While the family was sleeping in, I spent about an hour in the garage working on the fuel pump tubing. The Imperial bender works really well. Reading the instructions to figure out how to measure and mark the tubing takes a while, but the results are perfect. Once I got the hang of it, I didn’t have to redo any of the tubes (except when I stupidly left off the nut and sleeve before flaring).

I mounted the pump temporarily with some clecos to finish off the connections with the fuel selector. After a bad start a month ago, this ended up turning out very nice.

I spent the rest of the time fabricating all of the little parts needed for the cabin frame. It took quite a while to measure, cut, and shape these little buggers. (Edit: With Van’s recent modification of the cabin frame to F-706 attachment, four of the fabricated parts are no longer needed. Check before you bother to make all of the parts.) It’s hard to tell from the picture, but most of the parts are cut at an angle to allow the cabin frame to tilt back. I can’t imagine doing all of this without a band saw. I also drilled the large holes in the back of the frame with a hole saw.