Empennage | Andrew's RV-7 Build Log

Primed R-902 Rudder Spar

March 18, 2010

I was getting the itch to work on the airplane a little, so I tackled the R-902 Rudder Spar today. First thing, deburring. I know I have plenty of pictures of deburring , but I took a closeup of a few holes.

Hole on the left is deburred, hole on the right is not. This is the topside, though, so the raw hole on the right doesn't even have really bad burrs. The weird crap on the left is just a piece of metal left over from deburring, it's not really messed up.

Here’s an action shot of me using the oversized bit to deburr.

Action shot!

Here’s the spar, deburred, and ready for scuffing, cleaning, and priming. Sorry for all the pictures tonight.

R-902 Rudder Spar

Here’s a picture of me scuffing with my maroon scotchbrite pad. For some reason, I like this step in the airplane building process.

Left half is the raw spar, right half has been scuffed.

Then, Ginger noticed I was in the garage working, and since the garage temperature was the same as the house tonight, I left the door open.

"Jack, come out here and let's see what dad is doing."

Jack came to see what was going on.

Jack and ginger, curious as always. (They are collarless due to the baths they just got.)

To scuff the inside, I decided to clamp the spar down to the table. It makes scuffing slightly easier, and I can use two hands on the edges.

Some of my nice (but cheap) clamps from Harbor Freight earning their keep.

Next up, dimpling. The construction manual warns to maybe grind down the dies to make sure not to gouge the spar web. I didn’t seem to have any issues with clearance.

Dimpling with #40 tank dies.

Then, I took the spar inside and cleaned it with dawn dishwashing detergent. Then back outside to dry for priming. Here’s the spar in my fancy paint booth setup.

Spar, ready to be shot with primer.

I did the forward side of the spar first. (Notice the open garage door, I’m trying not to kill too many brain cells with the priming.)

Forward side of the spar primed.

A shot of the lower portion of the spar.

Then, after going inside to refill the wine glass (to let primer dry), play with the pups (let primer dry), and hang out with the girlfriend (let primer dry), I went back outside to prime the aft side of the spar.

The bright orange thing on the spar near the right 2x4 support is the reflection of a warning sticker above the garage door. The primer is still wet. I didn't see this until I uploaded the pictures.

After another half hour or so, I put the spar back on the table and clecoed the R-606PP (Lower Spar Reinforcement) and R-607PP (Middle Spar Reinforcement) to the spar, along with the appropriate K1000-6 nutplates.

I'm getting close to riveting again!

A closeup of the nutplate

I always get so excited when I get to this point.

That was pretty much it, except for more experimentation with the “macro” setting on my camera.

Eh. No reason for this picture. Just experimenting.

1.5 hours today. It felt nice to get a big piece like the spar done.

Prev | Next

Leave a Comment » | Empennage | Tagged: Construction Manual, Deburring, Dimpling, edges, Empennage, Ginger, Jack, Priming, Rudder, Scotchbrite, scuff, shoot, spar | Permalink
Posted by Andrew

More Small Rudder Parts Priming and Devinyling

March 15, 2010

Prev | Next

First thing after today’s realization that I had forgotten to dimple before priming, I rushed home and grabbed the tank dies to prime the #40 holes.

Let's get ready to dimple...

No problem to dimple after priming. (There was a little bit of twist after dimpling, but no big deal, the rivets will hold this thing together.)

Slight twisting after dimpling.

The only way you can tell I dimpled after priming is that the dreaded dimple circle is visible, because the outer edge of the dies mars, (maybe polishes?) the primer a little. You can see it in the pictures.

Dimpling after priming worked fine. See the circle marks?

Here’s the other side.

Looks good to me.

After I finished both, here they are on the table. Crisis averted. (Not really, I would have just re-primed them.)

These will do.

Then, inside to grill some dinner, then back out to do more edge finishing, cleaning, and priming. I grabbed R-606PP and R-607PP (lower and middle spar reinforcements) along with R-617 (shim) and finished the edges with the scotchbrite wheel. Once complete. I took them inside, cleaned them with dawn detergent, and brought them back out to dry and prime. Here’s a priming shot.

From left to right: R-606PP, R-607PP, and R-617.

Next, I looked around and grabbed the R-912 counterbalance rib and did some edge finishing and dimpling. Here’s a dimpling shot.

Dimples!

Same deal with with the R-903 tip rib and the R-710 horn brace. Here’s the horn brace.

More dimples.

After the primer dried on the three pieces I primed tonight, I put them back on the table and examined my progress. Still a long way to go.

A shot of the "table of small rudder parts."

Enough work outside for the night. I grabbed the soldering gun, my wooden straightedge, and the R-913 counterbalance skin and headed inside to devinyl.

Pretty, but maybe overkill.

I decided to leave some of the vinyl on here to save on primer on the inside and protect the finish on the outside. I think the amount of primer weight I am going to save by masking with the vinyl is minuscule compared to the parts I will inevitably need to re-prime. But, if I pulled off all the vinyl, and primed the entire interior surface, I would always know I was carrying around more primer than I needed to be. (It’s all about figuring out what you can sleep with at night.) While I am sure I will add more than plenty of unnecessary weight in other areas (all of the nutplates I am going to add), not doing this would make me feel lazy.

R-913 Counterbalance skin interior.

Next, I grabbed the R-901-R (right rudder skin)0 and pulled it inside to devinyl. Notice on the left that I made the cuts on the trailing edge (rudder is upside down in this picture) but haven’t pulled off the vinyl? I am going to leave the vinyl on while I prime the rest of the bare metal areas, then remove the trailing edge vinyl. This area doesn’t need to be primed, as it will get scuffed up with a scotchbrite before using Pro-seal to glue the two skin trailing edges and trailing edge wedge together.

Look at me, I've thought ahead!

Another shot of the right rudder skin, this time right-side-up. (Also, my fancy-pants wooden straight edge and a glass of 7 Deadly Zins Zinfandel.)

Next, I flipped that bad boy over and did the exterior. Here’s a shot before I’ve pulled some of the vinyl off.

I probably should have pulled more of the vinyl off of the leading edge, but it was just two more lines, and now I have a little protection on the leading edge while I am rolling and assembling.

Repeat for the left skin, and then I took both back outside and stored the left skin on the top shelf of my second toolbench.

I'm embarrassed that I don't have a one-piece shelf for the top shelf of my workbench. Don't judge me.

And a finished shot of the right skin, back out on the workbench.

I like these devinyled pieces. Can't explain it, but I like them.

I was using the clock in the kitchen to mark my progress, and decided I was going to stop at 9:30pm to head to bead…except (yeah, you know where this is going)…I forgot to reset that clock after the time change. It was actually 10:30pm and I had put in 2.5 hours. Great for airplane progress, bad for my sleep debt. I’m not going to put in any time tomorrow, need to catch up on sleep. See you in a couple days.

Prev | Next

Leave a Comment » | Empennage | Tagged: Devinyl, Dimpling, Empennage, Priming, Ribs, Rudder, skin, Vinyl, Workbench | Permalink
Posted by Andrew

Primed R-918s and R-608PP

March 14, 2010

Prev | Next

After a whole 10 days on vacation, a few flight delays, cancelled flights, rebooking to a city 6 hours away from home, lost bags, malfunctioning 737s, and a broken down rental car, I finally made it into the shop.

I know I wasn’t going to be able to put in hours and hours of work, but in the words of Bob, “baby steps.”

First of all, while I was gone, I got an order in from Avery. It contained the NAS 1097 “Oops” rivet kit, and two sets, both 1/8″, one straight, and one double offset. These were relatively cheap ($8 and $20, respectively) and I believe they will come in very handy. Here’s the merchandise.

I love buying tools. It's like crack, but more legal.

After unpacking the new tools, I finished deburring and edge finishing the R-918s.

A deburred and edge-finished R-918. I'm not sure which side this due to the glare in the picture. But you don't really care, though, do you? They are identical parts (although, make sure to keep them separate, because they've been matchdrilled to the rudder skins).

I shot a little primer on one side of those two pieces and started deburring and edge finishing R-608PP, which is the uppermost spar reinforcement plate. I shot a coat on one side of that, and the other side of the R-918s.

Ready to prime R-918s.

R-918s and R-608PP primed. They are still wet, which is why you can see the reflection of the garage insulation on the R-918s.

While waiting for those coats to dry, I unpacked my Oops rivet kit.

Which one of these labels isn't like the other?

All done and labeled.

I didn't have any more room in my rivet "briefcase" so I'll leave them in the included case.

Then, in a similar manner to Brad Oliver’s explanation page (another shot here), here’s my shot of some NAS 1097 rivets next to their AN426 counterparts.

AD3-3, 3.5, and 4 (AN426 and NAS 1097 of each to compare smaller heads for the same size rivet) and on the far right, an AN426AD3-3.5 and a NAS1097 AD4-3.5. Same size head.

From my understanding the AD3 (smaller) sizes are used when a smaller rivet head allows you to countersink thinner material (instead of having to dimple) in non-structural areas (dimples aid in the strength of the riveted pieces). Mostly, they are used where flush rivets are required to attach nutplates (so you don’t have to dimple the nutplates, which is apparently difficult).

The larger size (AD4) rivets are used primarily when you have messed up an exterior hole during riveting or drilling out a badly set rivet that you have to enlarge the hole. The smaller heads on the larger rivets match the regular sized rivet heads.

Once I got primer on those three parts, I put them back on the “table o’ small rudder parts”, to give you a good understanding of how much more tedious prep work I have to do before I can start riveting parts together. I can’t really complain. I love this stuff.

3 of 11 parts primed (and these are just the small parts).

A short half an hour today. Felt good.

NEXT DAY UPDATE:

CRAP!

Because the R-918 (rudder bottom fairing attach strips) go under the rudder skin and bottom rib, they need to be dimpled, and I forgot to do that last night.

Let’s see, rudder skin = regular #40 dimple dies, bottom rib = #40 tank dies, which means I’ll have to use the #40 tank dies on the R-918s, too. I wonder what the dies will do to a part that is already primed. I’ll give it a shot, take some pictures of the results, and re-prime if necessary. Boo.

Prev | Next

2 Comments | Empennage | Tagged: Avery, Countersinking, Deburring, Dimpling, edges, Empennage, Nutplates, Rudder, Scotchbrite, scuff, shoot, spar | Permalink
Posted by Andrew

Disassembled Rudder to Start Deburring

March 1, 2010

Prev | Next

I liked having the rudder assembled on the workbench over the last day or so. I got to walk by it going in and out of the house admiring how much it looked like an airplane part. I found myself saying, “that’s a rudder” every time I walked by.

Nevertheless, the next step in the construction manual has you disassemble the parts and start the long process of prep for priming and riveting.

Some of the rudder parts, disassembled.

I got everything taken apart yesterday, and then second-guessed myself. I am planning on attaching most, if not all, of the fiberglass fairings with screws and nutplates, which will require the usual dimpling/countersinking of the components. Here’s the catch. Take the rudder bottom fairing attach strips. If I disassemble, deburr, scuff, clean, prime, and rivet them back to the skin/bottom rib, I’ll be drilling through primed parts when I go to install the bottom fairing (and nutplates). Do people re-prime these parts (mainly the holes) after they are riveted to the almost complete rudder?

I’m thinking that maybe I should re-assemble everything, layout the spacing for the fastener attach points now, then go ahead and do the normal disassemble, debur, scuff, clean, prime, and rivet dance. I’m going to pose this question on VAF.

Anyway, with everything disassembled, I started to mark and deburr parts. In preparation for edge finishing, I removed all of the safety covers for the scotchbrite wheel side of my 6″ grinder.

Removed the scotchbrite wheel.

Removed all safety covers.

Reattached scotchbrite wheel.

Ready for some edge-finishing.

Then, I got back to deburring some of the smaller parts. When I finished deburring the holes in a part, I usually take a scotchbrite pad and “mark” the part with a few scuffs. That way, I know all the holes are deburred, and it is time to move on to edge finishing.

I only spent an hour outside today. Had to let the food digest before working out, then it was off to bed.

[yawn] I’m still tired, though.

Prev | Next

Leave a Comment » | Empennage | Tagged: Construction Manual, Countersinking, Deburring, Dimpling, edges, Empennage, Riveting, Rudder, Scotchbrite, scuff | Permalink
Posted by Andrew

Initial Rudder Assembly, Fabrication, and Drilling

February 28, 2010

Prev | Next

With the girlfriend out running errands, and the house to myself, I got to make as many loud noises as I wanted this morning.

First, I jumped back to the part in the directions where they have you enlarge the hole on the flange of the rudder bottom rib to 3/8″. I started with a #30, then #21, #12, 3/16″, 7/32″ and finally, 3/8″. (I may have also used a 5/32″ in there, too, I can’t remember. You can see it turned out pretty well. I didn’t take a picture every step, just a few so you get the idea.

Here's the #21.

#12

I think this might be the 7/32."

Finally, with the 3/8" bit. Looks good to me.

Then I disassembled to check the hole clearance on the flange.

Think I have 2 times diameter? Nope. Apparently, this is okay, since it is not a structural hole. This is as designed.

Next, time to fabricate R-917 (shim) per the plans. From other builders websites, I’ve gathered you are supposed to use the Trim Bundle, Emp.

Here's the trim bundle, fished out from one of my workbench shelves.

To give you an idea of what is included, there are 4 pieces of .032″ on the left, 3 pieces of .016″ in the middle, and 3 pieces of .025″ on the right.

0.032", 0.016", and 0.025", respectively.

The plans call out .032″.

Here's my piece.

Of course, it’s 2024. You can see the callout on the plans in the lower right corner.

I drew some lines on the piece...

I transfered the dimensions…

Dimensions!

Then, I made a rough pass with snips, and finished up on the scotchbrite wheel.

Scotchbrite wheel, compressor, and the newly fabricated R-917 shim.

I centerpunched the two outer hole markings, and drilled one hole to #30 per the plans, and one to #40. My plan is to matchrill the #30 hole (top one in the following picture), cleco it down, and then enlarge (matchdrill) the #40 hole to a #30 once I have everything fitted correctly. Here, you can see the lower hole in the shim doesn’t line up perfectly.

Lower hole doesn't line up perfectly. I used a file and the scotchbrite pad to clean up the right edge before enlarging to #30.

Next, they have you lay in the Rudder horn (R-405PD), cleco, and matchdrill the 4 upper #30 holes (right side of the picture).

The clecos on the right are holding R-606PP (spar reinforcement) on the forward side of the spar.

Next, they want you to round out the edge of R-405PD horn so it lays in nicely with the R-904 bottom rib. You can see here, it won’t work as is.

No good. Must round.

The scotchbrite wheel made quick work of this.

Much better.

After clecoing everything back to the spar, I flipped it over and matchdrilled all of the remaining #30 holes through the reinforcement plate, spar, shim, and rudder horn.

Matchrilling glory.

Then, I loaded up the #40 bit and matdrilled all of the holes in the counterbalance skin. Pictures of matchrilling aren’t interesting, so I just took one once I was done.

Boring matchdrilling.

THEN YOU GET TO CLECO ON THE SKIN! Wuhoo! Left side first…

Wuhoo! (Saggy trailing edge wuhoo, but wuhoo nonetheless.)

Then flip the bad boy over…

Ready to cleco on the right side.

And cleco on the right skin.

It's starting to look like a rudder.

Then, slide in the trailing edge wedge.

Trailing edge wedge...

Crap, I started clecoing it in backwards. This v shape is supposed to go forward, and the pointy end back.

It would be kind of a cool looking trailing edge, but...no.

Once I got it in the right direction, I took a step back to admire how much my rudder looks like a rudder. Then, I matchdrilled the remaining holes in the skin. There were a hole bunch, but I only took one picture at the end. Here you go.

The two skins completely matchdrilled.

Once that was done, I grabbed the rudder brace, and heeding some great advice from other builders, drew my cut line north of the guide holes.

Here's the left side.

And here’s the right side after the cut.

The right side guide hole is underneath the sticker. Sorry.

And the right side after cutting. You can see I stayed away from the line when using my snips. I’ll approach it carefully with the scotchbrite wheel.

asdf

After getting the brace close, I went through a couple fit and trim iterations before finally getting a good fit and getting the holes matchrilled.

Good fit, and matchrilled successfully.

With the brace complete, it was time to move on to the fairing attach strips. Here’s the piece they want you to use.

Rudder attach strip stock. Say that three times fast.

After trimming to 18 inches.

Two attach strips and a pieces of scrap.

Then, I transferred the dimensions on the drawing to the two strips

Ready to snip.

Then, I used the snips, clamped the two pieces together, and took them over to the scotchbrite wheel for some cleanup.

Here they are, ready to be drilled to the rudder.

To drill them on the rudder (without a lot of guidance from the manual), I clamped them in place (once I figured out where I wanted them, which appears to be up to you). I left about 1/16″ between the diagonal cutout on the strips and the back of the rudder brace.

Clamped, and ready to start drilling.

Because I generally don’t like drilling into my own fingers, I use two clamps around two holes, drill those two, and put a cleco in the second hole.

Clamp and drill, drill, cleco. Clamp and drill, drill, cleco. Down the line.

Here’s the after shot for the right attach strip.

Right attach strip complete.

I repeated the process for the left side. You don’t need any pictures, do you? Fine. Here’s an after shot.

Both attach strips done.

Finally, I found one rivet on the left skin that I wanted to drill out.

Sitting a little proud, eh?

#40 dril, right down the middle.

Centerpunched and drilled.

Then, I flip the bit around (or grab the back of a spare bit), stick it in the hole and…

Ready to remove the rivet.

BEND THAT MOFO OUT!

The rivet head pulling out.

After that, you are usually left with the shaft and shop head of the rivet stuck in the hole.

Part of the rivet remains.

You can use a punch or drill bit to push it out the backside.

Here's the hole, ready for a new rivet. Looks like I may need to clean up the hole a little on the right side. I'll take a closer look once I pull the skins off the skeleton.

Great day today. No rivets set, and one drilled out, but a ton of productive loud noise time while the girlfriend was out doing errands.

Prev | Next

Leave a Comment » | Empennage | Permalink
Posted by Andrew

Finished Backriveting Stiffeners

February 27, 2010

Prev | Next

I didn’t get to spend very much time in the shop today, but the half hour I did spend on the project was a good half hour.

I grabbed the stiffeners that I had primed on Friday night and laid (layed?) them on the left rudder skin.

Primed stiffeners, ready to be backriveted.

Then, I backriveted them.

All done.

Sorry about the lack of pictures.

116 backriveted flush rivets set.

Prev | Next

Leave a Comment » | Empennage | Tagged: Backriveting, Priming, Rudder, skin, Stiffeners | Permalink
Posted by Andrew

More Stiffeners, Some Skeleton

February 26, 2010

Prev | Next

Yes, Friday night! That means instead of being social, I get to stay home and work on the airplane. Wuhoo!

Anyway, after a good workout, I spent a couple hours in the airplane factory. First thing, I grabbed the two primed stiffeners from last night, and got them backriveted in.

#5 and #6 of 8 on the right rudder skin.

Then, I edge finished, scuffed, cleaned, and primed the last two stiffeners on the right skin. Once they were dry, I got those installed permanently, too.

#7 and #8 (two on the far left) of 8 on the right rudder skin.

I couldn’t help myself. I flipped the skin over, and removed the tape to reveal a very smooth skin. I like backriveting. The backriveting plate left some very very very small marks within about a dime sized area around the rivet heads, but I know those will polish out.

A finished right rudder skin. Those wrinkles in the vinyl in the middle where there when the skin was delivered. It didn't look like there was any damage underneath.

After spending some time admiring the right skin, I decided to finish the edges for the left skin’s stiffeners. After that, they got scuffed, cleaned, and set up on my fancy priming bench. Here they are ready for primer.

8 left skin stiffeners, ready for primer.

While those dried on one side, I decided to dive on in to the rudder skeleton. First, they have you cleco the R-904 root rib to the R-902 Spar. Tough step, but I managed.

Started on the rudder skeleton.

Then, because it was late, I had to skip the steps with the drilling and the fabricating the “shim” etc. I moved on to clecoing the spar reinforcement plates in. Here are the top two.

Fancy pants, huh?

Then, they have you grab the R-909? (tip rib) and R-912 counterbalance rib and cleco those to the spar after fluting, if necessary. It was necessary.

R-912 Counterbalance rib on the left, R-909 tip rib on the right. You can see I fluted the tip rib too much toward the aft end (top of the picture). I'll straighten it out tomorrow.

After that, they have you cleco the dreaded counterbalance skin to those two ribs. I’ve heard bad things about this step (mostly difficulty due to bad fit). Well, it was slightly difficult, but mainly due to perfect fit. If you start from the front (bottom right of the picture), everything will work out, but the fit is pretty precise. There is no slop in these prepunched kits.

The right side of the counterbalance skin clecoed on.

Then, I flipped the assembly over and clecoed on the left side of the counterbalance skin.

Left side clecoed on. (Hey, you can see my fancy fluting pliers back there.)

By then, the remaining stiffeners were dry on one side, so I shot the other side with primer and headed in for bed. (For blogging, and then bed.)

asdf

66 rivets today, all backriveted. Also, I passed 1000 rivets set today. A little bit of a milestone, although I think there are something like 20,000 rivets in the whole kit. So, I guess I’m 5% there.

Good night.

Prev | Next

2 Comments | Empennage | Tagged: Backriveting, cleco, Priming, shoot, skeleton, skin, spar | Permalink
Posted by Andrew

Stiffener Prep, Priming, and some Backriveting

February 25, 2010

Prev | Next

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!

Prev | Next

Leave a Comment » | Empennage | Tagged: Backriveting, Construction Manual, Empennage, Priming, Riveting, Stiffener, VS | Permalink
Posted by Andrew

Skin Dimpling and Priming

February 22, 2010

Prev | Next

I snuck home over lunch today to get a couple things done, one of which was work on the airplane loudly. First, I set up my c-frame and spent some time verifying, re-verifying, and trip verifying that I was going to dimple in the correct direction. These rudder skins are thin, and I didn’t want to make any mistakes here. I set the skins on the table with the exterior side up, and the c-frame with the male die above, pointing down, and then dimpled all the holes in the skin. Jack and Ginger (who were inside), clearly don’t like me dimpling with the c-frame and told me so with a pair of barks, each. We did get into a nice rhythm, though. [whack] Bark, bark…bark, bark. [whack] Bark, bark…bark, bark. It helped pass the time, but I hope I didn’t cause them too much stress.

My dimpling setup for the rudder skins.

After that, I flipped them over and cleaned the scuffed lines.

Skins cleaned and drying.

After drying, I shot them with some self-etching primer. I was at the end of one of the cans, and some of the stuff came out kind of splotchy, but I think it will look good after it dries. I can always lay down another coat.

The left skin after priming.

Another thing. I’ve been putting blue tape on the exterior side, then laying the skins down flat and shooting them with primer. When I do this, some primer gets into the dimple (from the underside I am priming), and kind of bounces off the sticky side of the blue tape and settles in the dimple on the finish side. Today, I made sure none of the holes were obscured; hopefully that will prevent any primer from getting on the exterior surface. I thought about taping the final rivets in the dimples, since that is the next step with the skins anyway, but I am not sure about using self-etching primer on unset rivets, then setting them. I have never seen that done before, and I don’t want to be the first guy to try. I’m sure I would have been okay, but the other way seemed to work fine.

And the right skin after priming.

After work, I put rivets in all of the dimples, taped them up, and flipped the skins over to lay the stiffeners in. One note, since I am using the tank dies, the rivet sizes must be lengthened in some places. All of the stiffener rivets were too short before setting, so I am going to substitute AN426AD3-3.5 rivets for the AN426AD3-3s called out in the plans. Except for the aft-most rivet in each row. The construction manual tells you to make sure you set this rivet fully, so I’m going to leave the shorter one in there.

See these rivets? They look okay, until you put the stiffener in

Once you get the stiffener in, you can see they aren’t the recommended 1.5 times diameter. I’m also a little concerned that the dimpled holes are a little big for the rivets. I didn’t notice this on the other components using the tank dies. Hmm. I’m going to look around and see if anyone else has encountered this.

Not long enough. (TWSS)

I was moving along merrily until I got to this hole. Doh!

Forgot to dimple this hole. I had to break out the c-frame just for this one lonely hole.

After I got all the rivets in and taped, I flipped the skin over.

These rivets will be long enough.

Then, one by one, I final trimmed the stiffeners (snipped the 90° corners off with the snips) and laid them in to see what it would look like.

asdf

A solid hour and a half. After edge prepping and priming the stiffeners, I should be ready to install the stiffeners permanently.

Prev | Next

Leave a Comment » | Empennage | Tagged: C-frame, Dimpling, Ginger, Jack, Priming, skin, VS | Permalink
Posted by Andrew

Skin Devinyling, Stiffener Dimpling

February 21, 2010

Prev | Next

We got a ton of work done on the house this weekend (paint, patio furniture), and a little work done on the airplane.

Yesterday morning over coffee, I brought the right rudder skin into the kitchen and started devinyling. After giving it a lot of thought, I am only going to remove the vinyl (and then scuff and prime) the rudder stiffener locations right now. Later, after matchrilling the skins to the skeletons, I’ll devinyl, scuff, and prime those mating surfaces.

A couple strips done.

After finishing up the exterior side of the skin, I flipped that bad boy over and started on the interior side. I was more careful about tracing lines here, because this is where the primer will go. (Although no one will ever see the inside of the rudder skin once I have it assembled.)

Here's my wooden stick I use to devinyl in a straight line.

After finishing the right skin, I brought in the left.

Here we go. Hmm. Dog bowls are empty, I think the pups must be hungry.

Here is the interior side of the left rudder skin.

Pretty devinyled strips. I think the exterior of the skin is done, too.

Then it was off to do some errands, one of which was a stop by Harbor Freight. I got a mailing the other day, and they had some fantastic deals on some things I wanted.

7-Piece Body Repair Kit. First, the “body repair kit” was $19.99. Look at the 4 bucking bars in there! I don’t really care about the hammers, but my small bucking bar was not really cutting it for some of the rivets I needed to buck. The best improvement with these new bars…hand holds. They have little cutouts in the side for your fingers so you can get a great hold on the bar. I’m happy.

11″ Locking C-clamp. These come in handy for clamping things around flanges. I needed one of these, and ended up walking away from Harbor Freight for about $6.

3-piece locking pliers. I have a small set of needle-nose locking pliers and love them, I figured for $4.99 for 3, I couldn’t go wrong. The quality isn’t the best (the screw mechanism is a little sticky), but they should work.

6-piece presicion pliers. I have a couple of these from various places and I love them. 4 pliers, and 2 cutters. I’m most looking forward to the extra long pliers second from the top. Those will help me overcome my huge sausage fingers.

Hooray shopping.

Also, I grabbed this $19.99 air filter/regulator. I wanted a better regulator/filter/oiler, and this one looks like it will fit the bill. I hope the quality is high enough to not disappoint me.

Air filer/regulator. Should work well, and will relieve me from having to oil my tools every day.

Next, I spent a ton of time deburring the skins. I think it is something like 119 holes per skin, times two sides, times two skins. Yes, my fingers hurt. Here I am scuffing the inside of the skins after deburring.

Deburring and scuffing.

I was getting fancy with the camera, so here’s a closeup of one of the strips after deburring and scuffing.

Deburred and scuffed strip on the interior side of the skin.

And another picture of a strip before scuffing. This hole has been deburred, though. i should have taken a picture of an un-deburred hole for you. Sorry.

Deburred, but not scuffed.

While Mike Bullock has his Natty Boh, I have my Blue Moon (well, Rising Moon, their seasonal).

The moon!

Scuffing the left skin.

More scuffing.

All done!Finally, I finished scuffing the interior of the skins. After I get these all cleaned up (it will be harder to clean after dimpling) , I can get these dimpled and primed.

All done!

Here’s a nice closeup of me deburring the stiffeners.

Deburring the stiffeners.

After finishing deburring all of the stiffeners (which is two more deburr operations for each of the holes from the skins), I pulled out the squeezer and tank dies (for the skeletons, which I’m considering understructure).

I like playing with these.

I decided to go ahead and scuff and dimple the stiffeners now, while I can’t make any loud noises (post 10pm). I should have edge finished the stiffeners first, but I’ll still be able to use the scotchbrite wheel on them after they are dimpled. To save time, I’ll edge finish these while I am priming the interior of the skins later this week. Anyway, here are some dimpling shots.