Umm, this is a pretty boring update, but I had to do something outside tonight. I grabbed an oversize drill bit and a scotchbrite square and did some duburring and scuffing of the stiffener holes in both aileron skins.
Tools of the trade.
I told you it was boring. 0.5 hour.
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Wings | Tagged: aileron, Deburr, scuff, Stiffener | 
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Posted by Andrew
After last night’s bummer of a screw up (mis-drilling the aileron spar reinforcement plates), I woke up in a cold sweat.
I thought I was going to have to order four more little plates, just to pay some ungodly amount of shipping from Van’s to here.
Then I rememberered the “Trim Bundle” than Van’s sends you. I think there may be some 0.040″ in there.
Sure enough (after measuring, finding some 0.045″, then taking the blue plastic off, and seeing that it was really 0.040″), I had something to continue working on the ailerons.
I went ahead and marked some 0.032" that I found, as well.
After some measuring, marking, and trimming, I have 4 new pieces.
Old and new.
Instead of clamping these to the spar, I decided to just use the old pieces to matchdrill the new ones.
I've clamped the new pieces under the old ones, but in the OTHER orientation.
After some drilling, scuffing, edge-finishing, and marking, I had four new reinforcement plates.
Like new.
I clamped them to the spar, and marked the appropriate holes for countersinking.
There are two holes on the outboard end of each spar, too.
After that, I looked around, and figured there was nothing else to do except start some stiffener fabrication.
I hate making stiffeners (see title of post for emphasis). It takes forever, there are pieces of aluminum flying everywhere, your hands get cut up, but, it’s necessary.
After about an hour of cutting, filing, snipping, edge finishing, and scuffing, I have 32 beatiful stiffeners to go into the aileron skins.
8 on each of the upper and lower surfaces of each aileron.
That sucked, but as long as I can salvage the rudder stiffeners, I think those were my last stiffeners!
2.0 hours.
Leave a Comment » | Wings | Tagged: Drilling, edge finishing, scuffing, Stiffener, Stiffeners | Permalink
Posted by Andrew
After another full weekend of housework, errands, etc., I managed to fit in some work on the right tank’s inboard rib.
First thing, I fished out some parts. Here, Vans has punched out three parts, T-407 and T-410.
Hmm...where are my snips?
I decided to pull both assemblies(?) out and get them all deburred at the same time.
Here are the two access hole doubler rings and four rib reinforcement plates after deburring.
I put two of the reinforcements and one of the rings away until needing them on the other tank.
Then, I took one of the rings, centered it over the stiffener bump on the inboard rib, and used a straightedge to find the center of the circle.
"x" marks the spot.
I know I’m not really working on the left tank right now, but I decided that since I KNOW the circle cutter is going to be a PITA, I’ll just go ahead and do the left rib, too.
I fished out the two end ribs for the left tank and marked them so I knew which is which.
L1 and L7.
Before mounting the ribs up on the drill press, I needed to find some wood backing. How’s this tank-rib-shaped piece right here?
Pepsi should pay me for the product placement.
Whoa. That sucked. It sucked so bad, I didn’t even take any pictures. Among other things, the circle cutter 1) wouldn’t stay in one diameter, 2) shook so badly I thought my workbench was going to fall over, 3) almost killed me twice.
But, I finally managed to get a decent looking hole.
Phew, I'm glad that's over.
See? Nice hole.
Oops, looks like the hole was a little big. No worries, edge distance for the rivets is just fine.
The hole in the rib is a little big...
After some more cursing, cheating death, and general unhappiness, I managed to get a better (appropriately sized) hole on the left inboard rib.
I think I'm going to throw away the fly cutter now. Stupid piece of crap.
Okay, I’m straying from the instructions a little here. Normally, they want you to take this access cover, hold it against the rib, and use the prepunched #19 holes to drill holes in the rib. Then, hold the stiffener right aligned with those holes, and drill the nutplate attach rivet holes. Clear?
Instead, I’m going to eyeball the clocking of the access cover (so the flat part doesn’t interfere with the indentation in the rib), then just use the stiffener ring for all the drilling. (I need to order a new access cover with no holes in it because I’m using flop tubes (don’t need the small hole), which means I need to move the float sender to the second bay (don’t need the large hole).)
You can see in this picture, the stiffener ring is laid in place, and it looks like the access cover is clocked correctly.
Access cover in the foreground, stiffener ring in the background.
Clamped.
Drilled.
Dimpled the rib, and countersunk the ring.
clecoed some K1000-8 nutplates in place.
Here’s where things got frustrating. Because I wasn’t paying attention, I just started riveting the nutplates in place.
Clearly I didn't countersink enough.
Another view. Yikes.
I drilled out six nutplates (didn’t enlarge any holes in the rib or stiffener), but couldn’t get the rivets out of the nutplates. They got THROWED AWAY!
Sorry, nutplates. You are going in the trash. It's not worth my time to fix you.
Okay, more countersinking, then try again. Still not deep enough? Ugh, more countersinking again, and finally, they were deep enough.
I got frustrated, so I stopped taking pictures. Sorry.
After much cursing and angry mumbling, I got all 24 rivets in for the 12 nutplates.
I had to drill out two more rivets because they were sitting a little proud. In the end though, I’m happy with the results.
These didn't need sealant because the access cover will be sealed over them.
A shop head shot.
24 rivets, 8 drilled out. (one third!? Ugh.)
2.0 glorious hours today.
Leave a Comment » | Wings | Tagged: countersunk, cover, deburred, dimpled, Drilled, Rib, rivets, Stiffener, Tanks | Permalink
Posted by Andrew
Well, it’s monday. And even though I have a couple things remaining on the right elevator, I am going to follow the flow of the directions and move on to the left elevator before coming back to finish both of them.
In addition to the items they want you to do to both at the same time (roll leading edges, install rod-end bearings, etc.), I’ll have to come back to do three things on the right elevator:
Anyway, on to the left elevator. Here’s the obligatory changing-of-the-plans shot.
On to the left elevator (and trim tab).
As I only have about a half an hour tonight, my plan was to just cover the basics. First, lay out all of the left elevator parts.
It doesn't look like a lot of work...
Devinyl the skeleton parts.
This picture is almost identical to the one before it, except for the missing blue vinyl on the skeleton parts.
Then, on to real work…kind of. The manual wants me to attach the hinge reinforcing plates to the spar, then move to the outer ribs.
Here you can see the two outer ribs fluted. I haven't straightened out the rib flanges yet, will get to that soon.
Blah blah blah, assemble the skeleton. For now, I didn’t do any match-drilling. I do that hole-by-hole as I take the thing apart.
This one will be more interesting due to the trim spar.
Finally, I found one more of the stiffener angles. I got that devinyled and then cut from hole to hole to form some of the smaller stiffeners.
More small stiffeners. These go between the main spar and the trim spar (ahead of the trim tab).
With that stuff done, I headed inside and caught someone with their hands in the cookie (doggie-treat) jar.
That bottom shelf has the doggie-treats on it. (We have really patient dogs. /sarcasm off)
Lucky you, I got some video.
Anyway, a short half hour of left elevator prep.
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Leave a Comment » | Empennage | Tagged: counterbalance, Devinyl, doggie-treat, fluted, Ginger, hinge reinforcing plates, install rod-end bearings, Jack, left elevator, Match-drilling, Ribs, right elevator, rivets, roll leading edges, RTV, skeleton, spar, Stiffener, trailing edges, trim spar, trim tab | Permalink
Posted by Andrew
I’ve been lacking in motivation recently due to some badly dimpled holes along the trailing edge of the right elevator. All last week, my error had been hanging over my head, and I was having trouble even motivating myself to fix them.
Saturday afternoon (writing this later) I mustered up some courage and drilled out 13 of the 14 trailing edge rivets on the right elevator. They are really not trailing edge rivets, but the aft-most rivets of each of the 14 stiffeners (7 on the upper skin, and 7 on the lower skin).
You can't even really see the damage in this picture...
Here’s a couple pictures of the damage.
You can see how the dimple kind of tweaked the skin. Boo damaged skin.
The above pictures was the worst one. This one was more typical.
A small ridge below the hole (in the picture) and a small dent above the hole (in the picture).
After getting them all drilled out (13 of them, one of them was good enough to leave alone), I set up the skin with a long backriveting plate underneath the offending holes and used a 2×4 laid spanwise on the stiffeners with some clamps to keep the skin surface flat. Then, I used 4 or 5 long pieces of tape to pull the upper skin back to allow plenty of room to work.
You can still see where the very trailing edge is starting to bend down. This is why I had the problem in the first place.
With no rivets in the holes, I used a small flush set (about 3/8″ diameter) and my rivet gun turned way down to flatten the dents (I’ll call them dents for dramatic purposes, but they were really just small impressions) and ridges (again, really just small high spots) flat. I put the flush set on either side of the existing dimple (which was okay, it was the area just outside of the dimple, where the edges of the dimple die set had tweaked the skin a little, where I was having my problem) and gave it a few taps.
After finishing one side, I took off the protective tape I was using and inspected. It ended up okay. I think if I were going to polish the empennage, it would bug me, but my latest paint scheme idea has me painting the elevators.
I did the other side, and then cleaned everything up, put some rivets back in the holes, and set up each side again with my fancy setup to actually backrivet the last hole of the stiffeners in place. It went perfectly, and I was really careful to hold everything very flat against the backriveting plate.
(By “perfectly,” I really mean “I messed up one of the holes, had to drill it out to #30 and use an oops rivet.” ) I’ll point it out.
Here are some examples of the replaced finished rivets.
This one looks great!
Pretty good. You can still kind of see where the damage was.
Holy crap, how did I do that to the rivet? This is the one that got drilled out again and replaced.
Here's the shop head for the oops rivet. This was my first real oops rivet. Not bad.
This one is okay.
Another very nice one.
It's not blurry in real life, I promise.
Whoa, who scratched my skin? It was probably the male part of the dimple die. That will hopefully polish out, (or it will get cleaned up and painted).
Another good one. In all of these, you can kind of see the larger diameter area that was dimpled.
This one is on the very end, as you can see the devinyling lines.
It looks the same as all the rest, of course, so you’ll never know, and I’ve already forgotten which side (top or bottom) it’s on.
Anyway, I drilled out 13 of the 14 original rivets, then had to redo one of those, so 14 rivets drilled out and reset successfully in an hour today. Not bad. I’ll add pictures when I can get them uploaded. Sorry for the lack of work recently.
Leave a Comment » | Empennage | Tagged: Backriveting, C-frame, Dimpling, edges, Elevator, Empennage, Riveting, skin, Stiffener | Permalink
Posted by Andrew
A few days ago I got a little time in on the project. I’ll see if I can remember what happened. 3 hours, 116 rivets…2 of them drilled out and reset. Here we go. First thing, in preparation for stiffener riveting was to get the skin devinyled. Here’s my devinyling table, wooden stick (won’t dissapate heat) and permanent marker.
Ready to use the soldering iron to devinyl.
After devinyling the inside of the right elevator skin.
For some reason I like devinyling. Don't ask me why.
Here’s the outside of the skin after devinyling. This actually takes a long time to do.
I just devinyled the stiffener holes. I'll devinyl the rest after drilling to the skeleton.
At some point last weekend (can’t remember which day), I was sent to Home Depot (maybe Lowe’s…it was a busy day) to grab some gardening supplies. I took the opportunity to grab some indoor/outdoor carpet for the workbenches.
Here's what I call my toolbench with a new carpet surface.
You should be able to see the “workbench”‘ with carpet on it in future pictures. Anyway, I grabbed the skin and did some deburring (interior and exterior) and some scuffing (interior only, for priming).
Scuffed strip on the left, non-scuffed on the right.
After a few more minutes, I dimpled the skin (no pictures, sorry), and then decided they were ready for priming.
Where is that self-etching primer?
i got the picture order backwards, so you’ll see the skin primed later, but here I am getting ready (or just finishing) stiffener edge prep. I usually use my Permagit block to knock down any ridges, edge deburring tool (pictured below) to chamfer both edges, and then a scotchbrite pad to smooth everything out.
Right elevator stiffeners and my edge deburring tool.
Here’s the picture of my primed skin.
It looks sloppy now, but wait until I get the vinyl off. Then the primed lines will look nice.
After the stiffener edge prep, the stiffeners got taken inside to be washed with dawn detergent.
Here are half of the stiffeners, being cleansed of their oily fingerprints and aluminum dust.
I decided to take a picture of how much detergent I use. Nothing really important, just camera-happy, I guess.
Dirty stiffeners need to be cleansed of their aluminum dust and fingerprints.
After cleaning, they go back outside for priming.
Boo-yeah, primed stiffeners.
While those were drying (and then flipped and sprayed on the other side), I placed rivets in the dimpled holes and taped them in place.
Rivets just asking to be beaten into submission.
I started to backrivet, and everything was going very smoothly.
Beautiful shop heads.
More beautiful shop heads.
God, I love backriveting.
But anyway, I got through all 116 rivets, then flipped everything over and saw these!
Ahh! Worst rivet ever!
This one is not so bad...
I figured out why this happened, and it falls squarely on me.
While I was dimpling, I didn’t pull the other half of the skin back well enough, so the skin side that was being dimpled was not sitting parallel to the faces of the dimple dies. One side of the die dented each of the last stiffener rivet holes on one side. The rivet in the second to last picture was flush against the backriveting plate, but the skin was dented, or above the backriveting plate.
I’m going to drill out all of the bad rivets on the trailing edge (of course, the worse of the bunch is on the top of the elevator, right where all of you are going to come look at my elevators), and then try to smooth out the skin by backriveting it with a flush set from the inside out.
It might ruin the skins, which will be expensive. I’ll be sure to take some pictures of the process. Maybe it will save one of you some time and frustration…
Leave a Comment » | Empennage | Tagged: debur, Devinyl, Elevator, Empennage, flush, prime, Rivet, scuff, skeleton, skins, Stiffener | Permalink
Posted by Andrew
Today was pretty boring. All I did was trim the aft end of right elevator’s stiffeners and prime the two spar reinforcement plates.
Here's half of my right elevator stiffeners.
Of course, I finished deburring, edge finishing, and cleaning the two right elevator spar reinforcements. I even got the girlfriend involved. She took the parts inside and scrubbed them down with dawn. Now it really is “our” airplane.
Two spar reinforcements, primed on one side.
While that one side was drying, I finished up with the stiffener trimming. Here’s a shot of my weapon of choice.
Stiffeners and snips.
After I finished my first 7 stiffeners, I laid them into the skin, just for kicks.
Stiffener work is boring, but it means that there is backriveting coming soon, and I love backriveting.
Drink of choice tonight (only during piddly stuff, never during “real” construction): Rum and Coke. Mmm. Rum.
Rum. Coke. Stiffeners. Sharpie. And a damn dirty workbench. (Those splotches are ski-wax drippings.)
Anyway, I think it was an hour tonight, including the 5 minutes of double duty with the girlfriend’s help. I’m gonna get her to help more.
Leave a Comment » | Empennage | Tagged: "our", Backriveting, Deburring, edge finishing, Elevator, girlfriend, prime, reinforcement plates, Rum, scrubbed, Sharpie, skin, Snips, spar, Stiffener, Workbench | Permalink
Posted by Andrew
After last night’s bad fitting trailing edge, I decided to mark where the dimples weren’t sitting properly, and enlarge the countersink ever so slightly.
The problem is that if you make the countersink large enough to accept the dimple perfectly, you create a knife-edge on the wedge. I guess that is why they have you use the aluminum as a drill guide for the countersink bit. After deburring the few knife edges that I got, it ended up working pretty well, but some of the holes are enlarged a little. With the pro-seal and the double-flush rivets, I am not too worried, but it still bugged me a little. It appears other builders have run into this issue as well.
Another shot of the not so good trailing edge before enlarging the countersinks.
Before I thought I would be able to tackle the rest of the trailing edge today, I got some of the “not-reachable-with-the-squeezer” rivets. here’s a shot of some shop heads for the counterbalance skin to skin rivets.
Decent shop heads.
I also finished up the rivets for the counterbalance rib.
More shop heads.
Then, I installed and removed the counterbalance enough to be able to file away some weight so the lead cleared the shop heads of the interfering rivets.
Nice tight fit today.
Here's the counterbalance. The best file for this left big cutouts, so don't judge me for these.
I also finished dimpling the tip rib and got it edge-finished, cleaned, and primed.
Waiting for primer to dry is like watching a pot of water boil. I can't complain though. It's dry to the touch in about 15 minutes.
Even though that was plenty of work for the day, I decided to tackle the trailing edge. I had everything I needed (Lowe’s didn’t have any RTV, but then I remembered I had some at home from my motorcycle habit, so I was in luck).
Here's me attempting to design a way to keep the trailing edges apart. This sucked, and I ended up using scrap 2x4 in between the stiffeners.
Here’s my tools. RTV, MEK, gloves (I used about 8 pairs) and the tank sealant.
Tools.
Don the gloves, and get ready to mix. I had to read the directions about 15 times before I understood. The hardener (I think) is in the tube part of the plunger. You stick the black piece (behind the big tube) into the hole in the plunger, and as you push the plunger from the bottom to the top, you push the black part so the hardener in the plunger is expelled into the larger tube. Confused yet?
Ready to mix. (I've already cleaned all of the parts.
After pushing the black piece (back on the table now) up to start the mixing process, you twist the plunger head while moving up and down, which starts to mix.
This is after about 75 strokes, which is what the directions say you have to do. I had to keep going. (I may have been doing something wrong, I don't know.) I kept going after this to get a more uniform "black death" color.
Then you unscrew the plunger shaft and screw in the nozzle. Okay, where is my caulking gun? I don’t have a caulking gun. OH MY GOD I FORGOT A CAULKING GUN.
Here it is fully mixed.
That’s okay, I just stuck the handle of a large screwdriver down the tube and it worked great.
Here's one side, ready to be spread out. I put a dab between each hole, and then used a scrap piece of aluminum to spread it out nice and evenly.
Another shot. This seemed to be an appropriate amount of sealer.
After that step, things started getting messy, and I had to change gloves a lot (it gets everywhere), so I stopped taking pictures. After I got both sides covered, I laid it into the scuffed and cleaned trailing edge area of the skin.
Look how good that looks. (Also, you can see my 2x4 spacers.)
Another shot.
Of course, I did a marvelous job putting a perfectly penny sized glob of RTV on the last (aft rivet) of the stiffeners before I removed the wood spacers and closed up. (The wood spacer near the bottom of the rudder was a pain in my ass. I lifted up the trailing edge a little with the top skin, so it stopped squeezing the block, and of course the block slid down toward the front of the rudder. Of course now I can’t let go, but I’m too far away from the other workbench to reach all of my long-reach tools. Ever see one of those situations where a guy has one foot in a boat and one foot on the dock, and he’s stretching and stretching? That was me. Except I finally reached a BFS (big freaking screwdriver) and managed to get the block out without contaminating any tank sealant or RTV.
Here's a blurry shot of the bottom RTV glob. Glob is a technical term.
Then, I got the rudder clecoed to the angle, wiped off any excess sealant, and moved the hole thing to the top shelf of my workbench.
Storage, kind of. I'm going to leave this for a whole week while I start on the elevators.
I think it was 11 rivets. 2 hours before the trailing edge, one hour for the trailing edge. The next post is still from today, but I am tracking it in another section and in another column for total time, so it’s getting its own post.
Leave a Comment » | Empennage | Tagged: cleco, edges, Empennage, Lowes, MDF, Pro-seal, Riveting, RTV, Rudder, scuff, skeleton, skin, Squeeze, Stiffener, Workbench | Permalink
Posted by Andrew
Tonight, I decided I wanted to get started on backriveting the stiffeners. First, I had to finish edge prepping them, and get them primed. Here are my edge prepping tools for these stiffeners.
Permagrit, scotchbrite, an edge deburring tool, and one of the stiffeners. Sorry about the dirty table, that's from me waxing my skis. See the big spot near the top of the picture. That's from me getting wax on the iron, and trying to scrape it off using the table. Maybe I'll turn my benchtop over tonight so I look like a clean builder again.
After getting a few of them prepped, I went ahead and started priming.
Stiffeners drying.
Here’s the right skin, ready to accept the stiffeners.
Right skin, with rivets ready to go.
At first, I tried this backriveting extra long double offset rivet set I got from Avery. I don’t really like this thing. With the pressure turned all the way up to 50 psig, the rivets weren’t really setting well, and the plastic sheath was marring the stiffeners.
Here's what I tried the for the first stiffener.
Although the results are good, I ended up switching to another set.
Very pretty. I'm sure some of that marring will come out during polish. Very nice surface, though.
Then I switched sets to a large7/16″ cupped set, which worked well to keep the set (with no plastic sheath) on the rivet as it was being driven, but left some of them with a little bit of a rounded edge. I’m sure this is okay, but need to have someone come look at it.
Still, they look pretty good.
Here’s a better shot. They are okay, but not perfect.
See the slight rounded edge to them? I'm sure that is okay.
I managed to get through 4 stiffeners before I started getting tired and went to bed.
4 of 8 stiffeners done on the right skin.
I pulled the tape off of the exterior side…these look really good. I am excited to maybe polish the rudder so you can all admire my work.
1 hour today, 50 rivets. Wuhoo!
Leave a Comment » | Empennage | Tagged: Backriveting, Construction Manual, Empennage, Priming, Riveting, Stiffener, VS | Permalink
Posted by Andrew
Andrew's RV-7 Build Log 