edges | Andrew's RV-7 Build Log

Rear Spar work

January 19, 2010

I didn’t mean to spend a lot of time in the garage tonight, but I ended up spending about 2.5 hours.

The only thing left I have to do on the HS before getting the rear spar on is…finishing the rear spar. First thing, finish edge prep, then some more scotchbriting and finally cleaning in the kitchen (“get that airplane part out of the kitchen!”). Here are the parts ready to go inside for some cleaning. You can see the PermaGrit block I’ve been using to edge-finish.

Nice and scotchbrited.

While I was waiting for those to dry before priming, I pulled off the vinyl off one of the right HS interior bays where I had forgotten it from the other day.

Clean interior!

Then, I scurried outside in the cold to prime the rear spar components (HS-603PPs and HS-609PPs), and came back inside to finish devinyling the other interior bay.

More clean interior!

Then, after quick two-hour break for dinner and a couple TV shows, I went back outside after normal bedtime once I knew the rear spar parts had dried. Here they are clecoed together with the elevator center bearing (VA-146) and the hinge brackets.

Rear spar clecoed together, ready for riveting.

Then I broke out the squeezer to squeeze some rivets. Why not?

My first action shot!

This took most of the build time tonight. Here are some shop heads for your enjoyment. Not perfect, but they all pass the rivet gage test.

Shop heads.

Then, I needed to bolt on the VA-146 center bearing. Time to go find some hardware. After a short search, I found the bolts (the correct ones are the short ones on the right).

4 bolts for the elevator center bearing bracket on the right.

Then I found the washers (the ones you are looking for are the thick ones). There were 24 of them in the bag. (Stop judging me for not putting all of my hardware in separate trays. Using the inventory sheet and the bags has worked well for me so far.)

Washers installed.

Then I found the nuts. I didn’t torque anything down yet, just finger tight. Need to get some torque seal soon.

Nuts!

Alright, time to go inside, it’s getting late. Here are a few pictures of the final product tonight.

Nice and riveted rear spar. For those of who who don't have the plans in front of you, there are a couple sets of empty holes. They get riveted to the HS skeleton. I didn't forget anything, I promise.

A more artsy shot showing beautiful machined heads. I love the look of the rivets on the grey primer.

So pretty.

And one more shot, just because I can.

Rear spar, ready to be installed into the HS.

120 rivets set today. I’ll have to drill out a couple of the AN470AD4-5 rivets they have you set in the outboard hinge brackets. The instructions insist the rivet callouts on the plans is correct, but they seemed a little long. In a few cases, the shop heads cracked on a diagonal (I’ll try to get a picture of this tomorrow) so I’ll have to drill them out and replace them. Not bad, though. My riveting drill-out batting average decreased from 10% to 7.3% today. Good day!

For future reference, I finished up my second can of self-etching primer. I did prime the whole practice kit, but still, that is a lot of self-etching primer. I think on the next can, i am going to weigh the full can, then weigh the empty can. Then maybe I can make a rudimentary guess at the weight of primer I’ve used. (Ignoring the weight of the compressed gas in the container.)

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Leave a Comment » | Empennage | Tagged: cleco, Devinyl, edges, Empennage, HS, Plans, Rear spar, Scotchbrite, skeleton, spar, Squeeze, Vinyl | Permalink
Posted by Andrew

Preliminary Edge Prep on VS Ribs

January 5, 2010

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No pictures tonight, but I spent 30 minutes getting some preliminary edge prep completed on the VS ribs. Basically, I took a file to the edges, then used my edge deburring tool to knock down the edges. I didn’t do this before clecoing the HS ribs together, and it scratched the skins a little.

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2 Comments | Empennage | Tagged: cleco, Deburring, edges, Ribs, VS | Permalink
Posted by Andrew

Deburr and Dimple HS skeleton

January 3, 2010

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Today was another short day.
I spent about 3.5 hours (here and there) deburring all of the holes in the HS skeleton and then dimpling any holes that needed it (skin to rib holes). I’m using Avery’s tank dimple dies for any dimples recieving other dimples (ribs only, which recieve the skin dimples) at the reccommendation of some other builders (namely Brad Oliver’s post). The resulting dimples look great so far. Sorry about the lack of pictures; edge finishing is not exciting.

These are just the right side HS ribs, but I did the left side, too. And all of the spars.

I also managed to edge and surface prep the left hand skeleton and one of the HS-609PPs.

Coming up next: more edge finishing and prep for priming, plus skin deburring and dimpling. I might finish up the left side stuff (since I can prime pretty quickly) and do a little riveting tonight. Or, wait and do the whole HS together. I haven’t decided yet. In the least, I need to clean up a little. There is aluminum everywhere.

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Leave a Comment » | Empennage | Tagged: Avery, Deburr, Dimpling, edges, HS, skeleton | Permalink
Posted by Andrew

Rear Spar, Front Spar

December 30, 2009

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Well, I finally started today. First thing I did was break the corners of the HS-609PP. I used my grinder, which did a good job, but got clogged with aluminum pretty quickly. I think my next big investment will be a bandsaw.

The requisite shot of before and after rounding edges.

Then I removed the blue vinyl from the rear spars (HS-603PP) and clecoed the 609s to the 603s. To do this, I needed to increase the radius of the 609s that rests against the web/flange intersection of the 603s. No big deal. Once I did this, they fit great. I didn’t finish the edge prep on the 609s, I’ll do this prior to priming everything. Then, I match-drilled all the holes, including enlarging the HS-708/HS-603PP (inboard rib attachment) holes to #21.

Rear spar reinforcements clecoed to Rear spar channels. It's starting to look like an airplane? Ha.

Next, the directions have you attach the elevator hinge brackets. After match-drilling all of the outboard brackets, they have you sandwich the VA-146 bearing in between HS-411APP to HS-411BPP.

Clecoing the center bearing supports in.

One one side is pre-punced, so you clamp, drill 4 holes, cleco, remove from the spar, and drill the rest of the holes.

Getting ready to drill.

Then I masked off special parts of the VA-146 to prep for priming.

Taped off the important stuff.

And then shoot some primer. (I’m using the rattle can self-etching primer.)

Scotchbrited, cleaned, and primed the center bearing.

Then reassemble and rivet. I found (contrary to some other builders) that the rivets called out in the plans made a great shop head. I think other builders went up a size. I’m definitely happy with my first six rivets.

The first six rivets.

Here’s everything on the rear spar clecoed back together.

All the hinge brackets clecoed in place.

Then, per the plans, I marked the taper and radius locations for the HS-710 and HS-714 reinforcement angles.

Marked the tapers on HS-710 and HS-714 per the plans.

It was a little late to be running the power tools, so instead, I marked the bend lines on the HS-702 front spar channels. This takes some careful measurement and marking, so take your time.

I also marked the bend lines on the front spar channels. (HS-702)

Then, I strayed from the plans a little. They have you use a 1/8″ bit to create a notch relief hole, then enlarge to 1/4″ using a unibit. I used snips and then a file. The second one turned out better than the first (which I hear is pretty common on everything in the project), and I had some trouble making them look perfect. (I know, things don’t have to be perfect, but it bugs me, anyway.) Biggest lesson learned: cut the flange in the correct place first, then unbend the flange to give you more material to work with. You can see in the top one in the picture below that I didn’t do this, and had to taper into the bend relief notch. (The bottom one below is better, nice straight line back to the relief notch.)

Finished HS-702 shaping with bend relief notches.

Then I bent HS-710, HS-714, and both HS-702s. I created a cardboard template using trigonometry. I took the tangent of 6 degrees. Which is a little over 0.1. (This means fromthe bend line, for every inch you go laterally, the angle will be just over 0.1 inches up.) That’s a little hard to measure, so I took the inverse (to figure out how many inches laterally I need to go for 1 inch up), and got just over 9.5 inches. I have a calibrated 6 inch ruler, so I divided by two, and ended up with mike’s numbers; 4.75″ over, and 0.5″ up.

Now that I have my template for six degrees, let’s get bending.

After trying a few methods in the vise, I ended up just lining up my bend line with the edge if the table, holding a wooden block over the piece, and putting a little pressure on it. If you go slowly, you can get 6 degrees pretty dead nuts on. I laid everything on top of eachother, and it all lined up very nicely.

Lastly, I finished the front spar section by dimpling the HS-702s, and countersinking (first ever countersink!) the HS-710 and HS-714 for the center two holes only. Remember, flush rivets go on the aft side here, so the countersink and the male dimple die go from back to front.