April 23rd, 2011

Didn't have time to work on the RV today, but I did stop by Jeff's hangar. He was kind enough not to laugh at my noob questions, looked at (and approved) my machine countersinking of the HS-903 spar. He said they were just about perfect.

He was also kind enough to give me a back riveting demo as well as show me now the dimple/countersink combo pulled up tight once you riveted it. I had mocked up a skin/spar setup with cheap piece of 1/8" aluminum bar from Lowe's aircraft supply matched up with a piece of the scrap skin that Van's "gives" you. It came out really nice actually.

Also got an appreciation for the skills you develop when you've riveted a lot. Jeff laid his gun up against a piece of wood, gave it a couple of taps to get it dialed in, then banged out 3 quick rivets just by ear. Perfect.

My tries were not so smooth. He suggested holding the back rivet set so it doesn't walk on you.

Both he and Tim R mentioned getting the V-groove deburring tool. Don't have one of those yet.

When we were at lunch Tim mentioned he had used the aircraft spruce epoxy primer. He said it worked much better than anything else he'd tried. Also recommended the cheap ($39) HLVP gun from Harbor Freight. Have to look at that guy.

Helped Nick with the mains - we're putting new tires/tubes on Tango now that we're done with our annual. Hopefully the airstop tubes will do as well as the nose wheel. Gets old trying to air up the mains every few days, especially with those wheel pants in the way.

April 22nd, 2011 machine countersink emp spars

3 hours

Machine countersank (sunk?) HS-902 front elevator spar and started on HS-903. I test fit them with the skins (of course) and there was daylight between the spar flange and the dimpled skin. Don't like that.

Read through the Van's instructions (they said countersink should be .05" deeper than an AN426 (got your Mk.8 eyeballs calibrated???). Dan Checkoway's excellent sheet metal series was similar. I figured a skosh more than flush sounded about right, but still wondered.

I sent Jeff Moreau an email (our chapter sheet metal tech counselor, rivet guru, flight instructor, hawker pilot, and builder of a gorgeous RV-8a). He said you definitely don't want to go too shallow, and suggested just a smidge deeper than flush.

He was also offered to inspect my test piece and give me a riveting demo if I'd drop by his hangar tomorrow. Twist my arm. Always looking for an opportunity to learn. I'll be out at CPK tomorrow anyway working on 08Tango after our annual.

April 16th, 2011 - DRDT table, deburring

9 hours

Finished disassembly of right elevator. Removed vinyl along rivet lines of skin. Deburred main ribs, nose ribs, and skin. Built a dimpling table for the DRDT-2. Dimpled skin and ribs at specified locations.

Cleaned up a larger tip for the wood burning tool I'm using for removing vinyl. The greater mass means it doesn't cool too much from the skin/ruler. It also has a longer edge so it makes a cleaner line. Worked much better than the old tip.

Still to do:

deburr front and rear spars, countersink #40 holes on spars, countersink spar and spar doublers in specified locations

April 15th - Right elevator

2 hours

Haven't had time to do anything since April 4th. This evening I match drilled the right elevator skins to the spars/ribs. Started working on trimming away the vinyl coating so I can deburr and dimple but still protect the remaining skin.

April 4, 2011 jig, assemble right horiz stab

8 hours

Took a day off today to work on the plane. Incredible weather. Almost 80 and no humidity. Pretty amazingly there was no rain or T/S either. Way too windy to go flying though or I would have.

Started out to work on the horizontal stabilizer jig and realized the other one was warped as well and I hadn't noticed. I'd already glued some cleats on the first one so I did the same to this one then messed around with stuff until it was dry.

Rigged some up gussets so the whole thing would be "plumb and level" as the plans require.

Leveled the table for good measure while I was at it, and discovered that my garage floor is not only not level (I expected a slight slope in the direction of the driveway) but it also slopes to the south. Tsk tsk.

After a lot of fiddling (I tried 3 different gusset ideas before I liked one) I finally had the jig squared away.

Decided to start on the right elevator first. Triple checked everything to make sure I knew which end went forward and which was was "up". Had to laugh at my noob mistake labeling all the parts, though it worked out fine.

When I was labeling everything after match drilling so I could put it back together again I put all the labels on the "bottom", i.e. the bottom flanges of both the ribs and spars. Each rib location had a number (R1, R2, etc). All nice and neat. Guess what is pressed against the skin when you assemble the parts? :)

Still had enough identifying info on the ribs to get by, but still kind of funny.

April 4, 2011 pictures