Deburring | Andrew's RV-7 Build Log

More Drilling, Deburring, Scuffing and Dimpling

May 9, 2010

After we got back from my first Pilots N Paws rescue, I was excited to keep working on the airplane.

I needed to start on the tip rib and counterbalance rib, so I needed to get the holes in the counterbalance to final size (#12, for a An509 screw).

I had some trouble awhile back with drilling the counterbalance holes to final size, and I don’t have any boelube, but i figured any lubrication would work better than none, so I poured some air tool oil into the holes and tried again.

This time, it worked much better. (I still got stuck a few times, but I didn’t come to a grinding halt like I did last time.)

Here's the counterbalance after drilling to #12.

I clecoed the counterbalance skin back onto these two ribs, inserted the counterbalance, and matchdrilled through those to make these holes in the ribs.

Nice job with the blurry picture, right?

Next up, deburring.

There's my trusty deburring bit.

Then scuffing.

Bottom rib (counterbalance rib) is scuffed.

After deburring and scuffing the tip rib, I dimpled all but the last 2 holes on the top and bottom of the rib.

The two non-dimpled holes are not shown here. I'll have to get the countersunk steel plate out to get those.

Next, I clecoed the counterbalance skin on the right elevator skin and marked with a permanent marker where I wanted to scuff and prime. Some of the edges here have to be broken to make the skins seam from spar to coutnerbalance skin a little smoother. More in a later post.

Above this line, the right elevator skin overlaps, and will need a coat of primer.

Then, out with the trusty blue tape.

Taped and ready for scuffing.

Then, I pulled out my #8 dimple dies (don’t have #10 dies, which are the correct dies for a #12 hole and AN509 screw) and dimpled the counterbalance skin. The countersinks on the right are the correct size. I need to figure out how to dimple the skin on the left a little more.

After this shot was taken, I screwed the correct screws into the assembly and tried to tighten them down to dimple more, but I didn't want to strip anything, and it wasn't really going to work.

I’m going to research how people did this without #10 dies later.

No rivets set, but a good hour on the plane.

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Leave a Comment » | Empennage | Tagged: Boelube, clecoed, counterbalance, Deburring, Drilling, matchdrilled, prime, Rib, right elevator, scuffing, skin, skin ribs | Permalink
Posted by Andrew

I Love Tungsten (Started Riveting Right Elevator)

May 8, 2010

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Well, this morning, the girlfriend ran some errands, and I got my house chores done early, so I headed out to the garage to make some loud noises. Recently, I’ve been taking one component at a time from drilled through primed. It make my work sessions less boring (not a full day of deburring lots of parts, but rather one day of drilling, deburring, scuffing, dimpling, cleaning, and priming one part).

Anyway, today, it was the right elevator spar’s turn.

First, deburring. There's my oversize drill bit spun in my fingers.

Then I put a nice scuff on all sides and edges.

Scuffed and edge finished.

Then, I broke out the tank dies to do some dimpling.

I love these dies. Such high quality.

I know you guys have seen tons of dimples from me, but I still take pictures.

The male side.

And the female side. Apparently I have not edge-finished yet.

After finished dimpling, I grabbed this shot down the length of the spar.

Right elevator spar, dimpled.

I forgot to take a picture of the countersinking I had to do on the front (flanged) side of the spar. The spar needs to be countersunk to hold the flush rivets attaching the E-709 Root Rib Right. The elevator control horn fits over them.

Then, inside for cleaning and back outside to the paint booth.

One side primed.

While I was waiting for the back side of the spar to dry, I went ahead and pulled the vinyl off both sides of the E-713 counterbalance skin.

The vinyl comes off a lot more easily when it is warm out.

Then, I got the other side of the spar primed, and prepped for some riveting. I had already prepped and primed the two reinforcement plates that get riveted to the back of the spar.

There's my new tungsten bucking bar.

Here’s my setup for spar riveting.

You can't see the reinforcement plate, but those clecos are holding it on.

After 8 rivets, all I can say is…WOW. I love this tungsten bucking bar. 8 perfect rivets. With the older, and smaller, bar I was using before, things were always bouncing around, and my hand was vibrating, etc. With this bar, it is so easy to rivet. I should have bought this at the beginning of the project.

Wow, these are amazing shop heads.

Here's the other side.

I spent about 2 minutes just staring at the bar. Amazing.

I thought I would show you my grip.

8 more, also perfect.

Wuhoo, this bucking bar is great!

And, the other side of those.

I wanted to buck these, but I thought it would be better to squeeze them.

The spar to E-709 rivets.

These are the flush rivets I was talking about earlier. Of course, when the primer is only 30 minutes old, and you try to clean up some smudges with MEK, the primer will rub off. Duh.

I re-shot some primer over this right after this picture.

What a great day. I got to make loud noises, and I’m in love (sorry girlfriend) with my new tungsten bucking bar.

20 rivets in 1.5 hours. Good day.

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Leave a Comment » | Empennage | Tagged: cleaning, Clecos, counterbalance, Countersinking, Deburring, Dimpling, drill bit, Drilling, edge finished, Elevator, MEK, Priming, Riveting, scuffing, shop heads, spar, Squeeze, tank dies, tungsten bucking bar, Vinyl | Permalink
Posted by Andrew

Bent Right Elevator Trailing Edge

April 28, 2010

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What a great night in the shop tonight. And, the airplane actually forced me to get something done on the house!

After work today, I needed to stop by the Aviation Depot to buy some hinges, wood, and an 1/8″ dowel rod for elevator trailing edge bending.

Since we’ve been wanting to upgrade the hardware in our house for awhile, I decided to buy the nice hinges, and used the replaced hinges for my bending brake. Here’s a shot of our powder room door, mid-installation.

Top hinge is the new “oil-rubbed bronze” hinge. Bottom hinge is the old (builder standard) hinge. Looks a lot better.

Up close. I like the new one a lot better. (Later, I went around and made sure all of the crosses in the screw heads were straight up and down. It’s an anal retentive thing I do, especially with light switch plates.)

Anyway, after a ton of VAF research, Orndorff video watching, and builder website reading, I settled on the “other” method, which puts the hinges on the long face, and really only bends with the short side of the 2×4 (or 2×8 cut in half). You really only want that much bending the skin anyway, because the bend needs to occur locally at the radius, not away from the trailing edge. If the wood is imparting force in the middle of the skin, you will end up with the dreaded “bulge.”

Here’s my bending brake being assembled. I had six hinges, so why use them. I grabbed these 2×4, which were nice and straight, and just long enough for the trailing edge. I’ll need to replace these for the flaps and ailerons. I read somewhere they need to be more like 5 feet long for those.

Here it is after assembly. On the left, you can see my skin, that needs to be bent. In the middle, the three dowel rods I purchased. While I was standing in the store, 1/8″ seemed too small, so I bought a few different sizes at $0.50 each. Of course, everyone was right on, 1/8″ is perfect.

I’m going to put the trailing edge of the skin in the little opening at the bottom of the brake (as it is oriented in the picture).

First thing, I screwed my bending brake to my 2nd workbench with one of the bending surfaces flush with the bench top.

Bending brake, installed.

Then, I put the 1/8″ dowel into the trailing edge of the skin and taped it in place. (Not shown in the following picture, because I was recreating the process for the camera. Look 2 pictures down for the dowel rod.) Then, you put the skin in the brake all the way against the hinges, and start bending.

This is not a fast process. It takes a surprising amount of force. I thought it was going to be a one shot deal, but it takes a lot of bending. You start with the skin against the hinges, then bend around the dowel. That took a whole bunch of times (I was stopping a lot to inspect). Then, you move the skin a little away from the hinge, and bend again. This allows you to really form the edge around the dowel.

If you pretend there is a dowel rod in there, this would be the first bend.

Here’s where I could get to with the dowel rod in place.

About halfway there.

Then, you remove the dowel rod and keep going, same deal, but a lot more gently, because I didn’t want to squeeze the trailing edge too much (now there is no dowel rod to prevent squash-age.

I thought this was good enough, but this is about 3/4 the way there.

Of course, because I thought that was good enough, I clecoed the skeleton into the skin.

It’s starting to look like something that could be considered an elevator.

But, after grabbing my straightedge, I’m getting some “fall-off” before the radius. This happens because the radius hasn’t been formed well, and then you pull the skin down to the skeleton, and it bends close to the trailing edge. It’s not terrible, but I know I can do better.

It’s not the dreaded bulge, but it is some pretty good “fall-off.”

Another shot.

No good here either.

Near the inboard edge.

Hmm. I unclecoed, and grabbed this shot. I’m about an inch from where I need to be, and the tension I am putting on the skin to pull it to the skeleton is causing that slight bend near the trailing edge.

About an inch.

I put that bad boy back in the brake and kept going. This time, I used two BFPs (the “p” stands for pliers. I’ll let you figure out the “b” and “f”) on either side of the brake and finished it up nicely.

More bending.

There we go. I made up that last inch, and now it rests right where the skeleton would go.

Much better. Perfect, in fact.

Here’s an end-on shot.

How great is this? A perfect bend.

Let’s get out the straightedge.

No fall-off before the radius.

Another place on the elevator.

And again, no fall-off. So happy!

After all that, I pulled the vinyl off of the outside of the elevator skins in preparation for deburring.

Hey! There’s shiny aluminum under there. Let’s start putting this bad boy together.

Total, it was two hours tonight, including bending brake construction. It was a great 2 hours though. I am extremely happy with the results. I have a perfectly bent trailing edge.

Boo-yeah.

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Leave a Comment » | Empennage | Tagged: ailerons, Aviation Depot, bending brake, clecoed, Deburring, dowel rod, Elevator, flaps, hinges, Orndorff, skeleton, skin, skin. Vinyl, Squeeze, trailing edge bending, VAF, Workbench | Permalink
Posted by Andrew

Right Elevator Stiffeners and Priming

April 12, 2010

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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.

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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

Rudder Skin Prep, Skeleton Riveting

March 20, 2010

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In between some yardwork, watching the sprinklers, and cleaning up the house, I made some good progress on the airplane.

First thing, I found a stiffener rivet that was sitting a little proud. (Drilled rivet #1 today.)

Off with your head!

Silly me, though, I didn’t get any pictures of it after it was reset. I was being lazy with the camera today. Sorry.

Next up, skin deburring and dimpling.

The holes on the right are the tip rib #40 holes. The ones on the left have been drilled to #30.

After deburring, scuffing and dimpling, we are ready for priming.

The top of the right rudder skin after deburring, scuffing and dimpling.

Then, more deburring, scuffing and dimpling.

I didn't forget the hole on the bottom of the picture. This hole is match-drilled with the rudder tip and then dimpled to #30.

After cleaning, I shot a little primer on the skin.

Primed right rudder skin.

I had a very specific order here. First, deburr, scuff, dimple and prime the top, forward edge, and bottom edge. Then, while the primer is drying, devinyl the aft edge (vinyl used as masking for the primer), deburr, scuff and dimple the aft edge. This edge doesn’t get primed, as we’ll use the fuel tank sealing instructions with Pro-seal to glue the trailing edges together.

After scuffing the aft edge, I started pulling off the blue vinyl from the interior of the skins.

This just looks so nice.

Another shot of me devinyling.

Then, I spent a couple minutes making the slot at the bottom of the skin a little bigger. One of the flanges from the control horn fits in here, and during initial assembly, there was some interference.

Notch enlarged.

And the left skin, primed.

Got the left skin primed and ready for devinyling.

Ame thing on this skin, while the primer was drying, I devinyled the trailing edge, scuffed, and dimpled.

Scuffed and dimpled the trailing edge.

Here’s the left skin after devinyling. I’ll store this skin until final riveting. Now, back to the skeleton.

Shot 1 of 2 of the prepped left rudder skin.

Shot 2 of 2 of the prepped left rudder skin.

In the middle of the day, I ran out of primer and scotchbrite pads, so I ran out for both.

Napa 7220 Self Etching Primer.

Maroon scotchbrite pads.

They didn’t have any maroon on the shelf, but they had some grey. I asked the guy out front, and he went to the back and grabbed 3 unpackaged pieces. Usually, there are $5 or $6 for the three. He gave them to me for a couple dollars, which was nice.

I like them cut in about 2" x 2" squares. Good to go until the end of the tail kit, I'm guessing.

I had some trouble with dimpling the last three holes in the rudder bottom rib. I drilled and countersunk a hole in a spare piece of steel I had, then realized it was too far from the edge to work. Awesome. Here’s a shot of my second attempt.

The new hole is on the bottom right. After countersinking, I used a rivet and my flush set to dimple the rib. Not perfect, but it'll work.

Then, I moved on to some riveting.

This is the spar and one of the spar reinforcements.

While I was moving everything around getting it ready for riveting, I broke my first tool. Now, it was about $0.50 from Harbor Freight, but I was still upset.

RIP cheap plastic clamp. (I'm lying. I actually gut the orange part off the other side and threw the clamp into a box somewhere. I'm sure it will come in handy at some point, even if it doesn't have the orange pads.)

Rivets were looking good, until the one to the right of the nutplate. Doh!

Which one of these is not like the other?

After a successful drill out (#2 of the day), I finished setting the rest of the spar reinforcements and snapped these two pictures.

Middle spar reinforcement.

Upper spar reinforcement.

That’s 16 set so far.

Then I mocked up the R-405PD Rudder Horn, R-710 Horn Brace, R-917 Shim, R-902 Spar, and R-904 Bottom Rib. Some people need to use blind rivets in some of these holes, but I figured I could do it with all solid rivets.

This is what I need to end up with after riveting.

I figured out that if I take off the R-904 bottom rib, I can reach in from above (bottom right of the picture) and get the horn brace to rudder horn rivets here, then slide the forward flange of the bottom rib under the rudder horn and get those from the lightening hole. Here I am setting the horn brace to rudder horn rivets.

I think this is going to work out well.

Another shot from further away.

Here’s all four of those set (set nicely, if I may add).

Horn brace to rudder horn rivets.

20 rivets set so far. Then I moved on to the R-606PP Reinforcement plate to R-902 Spar to R-917 Shim to R-405PD Rudder horn rivets. These need to be AN470AD4-7 rivets, which are LONG. I did have to drill one of them out. That’s #3 for the day. Boo.

This is an AN470AD4-7 rivet after drilling out. This is a long rivet.

But, I managed to reset it okay and get the others in with no trouble.

R-606PP to R-902 to R-917 to R-405PD rivets.

23 set. I scratched the R-405PD horn a little, so I scotchbrited it out, and shot some primer in there.

Some primer to cover the scratch.

Next, I slid the flange of the bottom rib under the rudder horn and lined up the holes. Now I need to drop some rivets in here.

Ready for riveting.

First, I set the horn brace to bottom rib rivets.

26 rivets set so far. These are looking good.

26 set. Finally, I set three more which are reinforcement plate to spar rivets.

These are above the bottom rib, so they are only reinforcement plate to spar rivets. Easy.

I started to rivet the complicated stuff together and LOOK WHAT I DID!

I think this is hilarious. Think I should drill it out?

This happened because I was bucking from above and shooting from below. The gun jumped around cause I was supporting it’s weight instead of letting gravity help me. That’s a no-no.

It was pretty easy to drill out (#4 for the day), here’s an inside shot; back to square one.

Ready to try again.

After setting the first two, a picture.

These look good.

And after much consternation (including using my double offset set as a bucking bar), I got the two outside rivets bucked.

Finally done with riveting for the day.

30 rivets set, 4 drilled out. Lastly, I matchrdrilled the E-614-020 to R-912 rib. This was a piece of pie.

Rudder counterbalance matchrilled to the counterbalance rib. Also, there's the hardware that will be used to fasten these two together.

4.5 hours today. Not bad for a Saturday afternoon.

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Leave a Comment » | Empennage | Tagged: Buck, Deburring, Devinyl, Dimpling, Empennage, Match-drilling, Priming, Ribs, Riveting, Rudder, Scotchbrite, scuff, shoot, skeleton, skin, spar, Vinyl | Permalink
Posted by Andrew

Primed R-902 Rudder Spar

March 18, 2010

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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.

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

Primed R-918s and R-608PP

March 14, 2010

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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.

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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

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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.

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

Skin Devinyling, Stiffener Dimpling

February 21, 2010

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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.

Getting ready to dimple.

Squeezing.

The end result.

A few minutes of this, and the right stiffeners are done (still not edge finished, though).

Right side stiffeners done.

Wash, rinse, repeat for the left side.

Both sets of stiffeners done. Time for bed.

2.5 hours today. Boring, tedious work, but still the most fun a man can have with his clothes on.

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Leave a Comment » | Empennage | Tagged: Deburring, Devinyl, Dimpling, Empennage, Squeeze, Vinyl, VS | Permalink
Posted by Andrew

More Rudder Stiffeners

February 20, 2010

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After a very busy end of the work week, I managed to squeeze a couple hours of airplane time in the shop today. I started by mocking up the R-902 front spar, and drawing a black line on the left rudder skin (this is the forward bottom edge of the left skin). I’m going to draw out all of the mating surfaces on these skins, since they will have to be primed at different times (more on this later).

Forward bottom corner of the left skin. You can see the front end of the only full size stiffener.

Next, I dove into match-drilling the stiffeners and skin. Here are the first size holes drilled. I don’t want any waviness in the rudder, so I am clecoing every hole as I drill. (You can see that like everyone else, I am drilling straight into the MDF that’s on top of my workbench. This works well, and is basically per the plans.

First six holes of the stiffener to skin match-drilling process.

After I finished the first (lower) stiffener, the next one needed to be cut down to size. I made another mark on that stiffener, this time in line with the front spar line I drew earlier. Now, when I trim the stiffeners on the aft side of that line, there will be no interference with the front spar.

Getting ready to trim the second stiffener.

Then, I got in the groove, so the next picture was after a few of the stiffeners. I used my cordless for this. Not as noisy.

Lower 4 stiffeners done on the left skin.

All done with the left side. Oh yeah, it was 60° today, so I worked with the garage door open. So nice…

There's something really rewarding about getting to this point. OH MY GOD!, WHAT IS THAT MARK BETWEEN THE FIRST TWO STIFFENERS!?

A closer look…

AHHHHHHHHHHHHHHH!

I turns out I dropped my cleco pliers from about 8 inches right after I completed the first stiffener. Instead of immediately pulling up the stiffener to inspect the exterior skin, I guessed that it was going to be salvageable and pressed on.

To put it into context, it is just above the first "L" in "ALCLAD."

It’s not that bad, but it would be very noticeable If I polish. (Even if I paint, it is still a pretty big mark.

From the other (exterior) side. Bummer.

Anyway, I’ve heard people talking about using the back of a spoon to gently massage stuff like this out. I spent about 15 minutes gently massaging, and I ended up with this. It looks worse than the original picture, but it is pretty flush now, and I think with a little more work may even go away.

After massaging. It's good, but not great.

Anyway, after that fiasco, I laid out the right skin, marked the front spar and trailing edge wedge on the skin, and started match-drilling stiffeners. I was in such a groove that I forgot to take a picture when I had all of the stiffeners drilled and clecoed. (I didn’t forget to take a moment to admire it, I just forgot to share it with you.)

After removing most of the clecos post match-drilling.

Also, while all the stiffeners were in place, I drew lines on each side of the stiffeners so I would have a guide for devinyling.

I call it match-drawing.

After pondering my next few steps (debur, dimple, scuff, clean, prime, backrivet the stiffeners on), I decided I need to get the vinyl off for deburring.

Here's the wooden stick I use as a guide for the soldering iron.

I don’t think I’ve shown you guys my round-tipped soldering iron yet. Here you go.

Soldering iron, heating up.

After running the soldering iron down the pre-drawn lines, I get to devinyl. I say “get to” because I like this part.

Whose fingers are those?

All done with the stiffener devinyling. You can see I didn’t do all of the outlined parts, because I want to prep and prime those later. (Have to assemble the skeleton, cleco on the skin, and match drill before you can debur, dimple, prep, etc. the rest of the stuff. Also, I need to find out if people are priming the trailing edge area before using Pro-seal. I have a feeling people are just scuffing, but I’ll ask the forums to make sure.