Right Elevator Finished

Not a ton of progress on the plane today.  Instead I pulled out the chainsaw and started cutting up the trees that came down in the last storm.  Next weekend will be log moving weekend.

I pulled the aluminum angle off of the trailing edge, dropped rivets in the holes, then put tape on them to get ready for back riveting. 

For the trailing edge, the rivets are double back set (not sure if that's the term, but it's what it is).  Because the wedge is at an angle, you start by back riveting as normal, starting perpendicular to the back rivet plate.  As the rivet starts to set, you angle the rivet gun to be parallel with the wedge.  That partially sets the shop head of the rivet into the dimple.  Per the instructions, I partially set every tenth rivet or so, then went back and partially set everything in between. This is to try to keep an eye on the straightness of the edge so you can correct any bow that happens.  All I can say is easier said than done!  In the end, I did have a bow to the edge, but it is within the spec Van's calls out.  They say to try to keep any bows to 1/10."  It's hard to tell for sure, but I'd guess the bow in mine is about 1/16" at the worst spot.  I know big deviations from straight can cause handling problems, but I can't imagine a 1/16" hook to the elevator will cause any problems.

After partially setting the rivets using the back rivet set in the gun, I flipped over the elevator and back riveted from the opposite side.  This puts the shop head down against the steel plate, so I used a mushroom set in the gun against the shop head.  When it's all said and done, the shop head sits very nicely within the dimple, giving a double flush rivet.  In the picture below, the rivets at the top are the shop head, compared to the manufactured head of the rivet below.

There were still a few rivets in the aft edges of the ribs that I had left open to allow me to open the skins enough to finish with the wedge.  These rivets are too tight to even get my new no-hole yoke into, so I couldn't use the squeezer.  I used a technique I saw on one of the EAA videos instead.  I put a piece of steel onto the rivet and used the gun to back rivet it from an offset.

I don't have a picture for the last step of the elevator - filing down the portion of the wedge that was extending beyond the skins.  There was a good 1/8" of material to file down, so I hit it with the belt sander first instead.  After that, I finished with a file and then sand paper. The skins are much tighter to the wedge than on the rudder.  I'm guessing that's due to the fact that I used the rollers to slightly bend the skins in before I dimpled.  So aside from the slight bow in the trailing edge, I'd say this edge is 50 percent better than the rudder.  Maybe the trailing edge of the left elevator will be even better.

Left Elevator

I corrected the warp in the trailing edge by re-drilling the aluminum angle while the whole elevator was weighted down to the table.  That made a big difference and it looks like the edge is very straight now.  I applied the VHB tape and got everything stuck together, stepped back to admire how much better it worked this time, and quickly realized I forgot to upsize one of the countersinks in the wedge.  While match drilling the holes earlier, I let the drill bit wander just a bit, which made an oblong hole in the bottom skin. Nothing terrible, but a regular 3/32" rivet wouldn't work anymore.  I dimpled the hole in the skin to the larger size, but managed to forget to do the same to the wedge.  So I had to pull the skin and wedge apart (that tape is amazingly strong) so I could re-countersink the wedge in that one spot. Well, maybe I'll finally get it right the first time when I do the trailing edge of the left elevator.

So now the whole contraption is put together and I'm just letting it sit tonight to see if the tape will adhere for the second time.  Hopefully I don't have to clean it off and do it all over again.  Considering the tape is purely for ease of assembly and has nothing to do with structural integrity, as long as I can rivet without things moving, I should be okay.

While the right elevator marinates, I figured I'd start on the left elevator. The left side is significantly different than the right, but the overall process is pretty similar in terms of assembly.  That's good, since the instructions are progressively getting lighter and lighter in detail.  At this point, Van's expects you to be able to read one sentence and realize there are 5 steps to go through to complete the task.

The reinforcement plates got attached to the spar and match drilled.

Then the spar was installed into the skin.

That was followed by fitting the end rib and trim tab spar.  The hole in the skin is where the trim servo goes (I'm doing electronic), and the cutout in the skin is where the trim tab itself goes.

I match drilled the spar, skin and ribs.  Even though the underside of the spar and skin are pre-drilled for #40s, they actually require a #30 enlargement since they will use 4-4 blind rivets, just like the right elevator.

The area where the trim servo fits gets a doubler mounted around the hole in the skin, then the plate where the servo motor itself sits is attached to the doubler using nut plates.

Final step for tonight was finishing up the stiffeners.  I had done all of the normal length stiffeners in one batch when I built the right elevator, but there are 9 smaller stiffeners in the construction of the left elevator because of the trim tab.  They aren't pre-measured like the other stiffeners, but there's a callout on the plans that clearly shows the measurements.  So after a few minutes of layout, I cut them on the bandsaw, snuck up on my lines a little more using the disc sander, then finished them off using the scotch brite wheel.  I still have to finish up the edges with sandpaper, but I'll do that after I've match drilled them to the skins.

Right Elevator - Almost Done

Surprise surprise, still working on the right elevator.  I weighed down the skins and proceeded to rivet on the bottom skins.  I'm very glad I chose to drill the skin and spar for the CS 4-4 blind rivets vs solid rivets.  I was able to pop rivet the spar in 10 minutes, but had I chosen mostly solid rivets, it would have easily been a couple of hours of irritation.  I know some people don't like the look of pop rivets, but I really don't see what the fuss is about.  Especially on the bottom side of the elevator, they're not going to be noticeable, especially since they fit flush in the dimples.

With the bottom side of the spar riveted, the counterbalance ribs were next.

There was really no easy way to rivet the spar to rib rivets.  I couldn't get a squeezer on them, so I had to figure out how to buck them.  By the time I'm done with the build I will have amassed quite the collection of steel bars that have been repurposed as bucking bars.  A little cardboard to set the bar at the right depth and I was able to get the four rivets set.

I finished all of the counterbalance ribs and skin, leaving open the aft 3 rivets on the ribs so I could still flex the skin enough to work on the trailing edge.  The wedge for the trailing edge is not pre-drilled like it was on the rudder.  I drew a line 7/32" from the front edge of the wedge to line the holes in the skin up with when drilling through the wedge.

I cut the wedge to length and lined up the holes in the skin with the line on the wedge.  Using the skin holes as a guide, I drilled through the wedge and other side of the skin using a wood block template made to the 84 degrees called out in the plans.

I didn't love how the skins set on the wedge when doing the rudder, so this time I rolled the skin using the edge roller from Cleaveland.  This is just a pair of vice grips that have rollers on them with a very slight angle at the edge.  The amount of angle it gives the skin edge is very slight, but it's supposedly enough to allow them to still be tight even with a little puckering between rivets.  I'll know if it works soon enough.

Following the process I did for the rudder, I started drilling through the aluminum angle to create a straight edge that the skin and tape combo could set up on.  I ran into a problem though.  Everything looked great, and then I got to the last 6" of the edge.  Everything that had been flat all of the sudden sprung up and bowed a 1/2" away from the angle!  At first I was pretty disheartened, because it seemed like I had done everything I could do to keep things straight, but after a bit of head scratching, I think I figured out the problem.  When I was drilling into the angle I didn't have the elevator weighted down to the table, which over the span of the elevator allowed the skins to slowly get pushed out of position against the wedge.

I reset and started over, this time keeping the whole elevator weighed down to the table while drilling through the angle.  I should finish up with the trailing edge tomorrow.  Fingers crossed it's at least incrementally better than the rudder.

Right Elevator Cont'd

First thing on the list to do today was to bite the bullet and rivet the spar to the top skin.  I have no idea why, but Van's designed the spar so that the flange opens to the closed, pre-bent portion of the skin.  I'm sure there's a reason, but it's awfully inconvenient for riveting. If it faced the other direction, it would be pretty easy to rivet, but as is you can't get a bucking bar anywhere near the rivets without figuring out a way keep the skins open while at the same time allowing the spar to line up for riveting.  So without having the free labor of family, I was back to using ropes, clamps, and weights to open the skins up and keep them that way.  In the end it worked out pretty well, but boy was it awkward.  I'm learning awkward riveting positions are pretty much the norm though, so getting used to it.

All of these rivets had to be bucked blind, but after a while you learn the rhythm and sound of good and problematic rivets.  I had to go back and hit a few again after visual inspection, but the vast majority turned out fine the first time around.  I'm still anal enough that I check at least my first handful of rivets with a rivet gauge each day, but it's becoming easier and easier to tell by eye how they are.  For the blind ones, pushing a finger against the shop head and then looking at the divot in my skin is really the only way to get a quick idea of how things are going. If I repositioned to look at every single rivet, I'd add hours to each riveting session.

After the spar was riveted to the top skin, I repeated the previous method of back riveting the stiffeners to the bottom skin. The weights might be overkill, but they really help to keep the skins flat so I have to use less pressure to ensure that I don't get a rivet bulge in between the parts.

And here's where I stumbled on another task where I questioned why it's not done earlier in the build sequence.  The counterbalance ribs and skin are next to be riveted to the spar and skin, but because the skin is already riveted to the spar, access to the rivets holding the ribs to the spar is extremely tight.  It sure would have been a lot easier to rivet the counterbalance ribs in place before doing the spar.  I still haven't figured out how I'm going to pull this off.  You can just barely see two of the 4 problem rivets tucked in behind the curved skin.  I tried getting a squeezer in there by opening up the skin, but there is still too much other stuff in the way.  I think I'm going to have to figure out a long, thin bucking bar and try to buck these.  I hung it up for the night so I could do a little digging and see if anyone has come up with a better way.  I'll tackle these tomorrow and then move on to the trailing edge.

Right Elevator Riveting

The next step of assembly of the right elevator is to rivet together the counterbalance ribs.  They are simply riveted together through the web.

That was followed by riveting the counterbalance skin onto those ribs.  I am learning from my previous mistakes!  Instead of filling all of the holes with rivets out of excitement (like I did a few times early on in my riveting career), I made sure to check the plans and leave holes open for areas that will accept the elevator skin at a later step.  The big holes on the outside of the counterbalance skin are the attachment points for the fiberglass tips.

The elevator control horn is attached to the inboard rib and spar.

Lastly for tonight, the top skin stiffeners were back riveted on.  It took as long to place the teeny tiny rivets in all of those holes as it did to actually set them.  I did notice that there are a number of areas on the skin that are pretty light in terms of primer.  I sprayed the insides of this skin in a major rush just as the rain was starting, so it's not surprising.  I'll take a look at it again in the light once I'm done with all of the stiffeners and decide if I need to get the coverage a little better.  If I do, I won't bother setting up to spray the primer.  I'll just use a sponge or something to dab the areas that need it (the primer manufacturer actually recommends using a foam roller to apply the primer if you don't have a spray gun).  This area just needs protection, not artwork.  Once it's riveted, it'll never see the light of day ever again.

Right Elevator Assembly

I'm still attempting to get to bed at a reasonable hour, so only had a few minutes to work tonight.  I'm trying to do something on the plane on most days though, even if it's just 30 minutes. Tonight I just squeezed a few rivets to attach the reinforcement plates and nut plates to the right elevator spar.  There is something immensely satisfying about squeezing rivets - watching the rivets squish down to a consistent size time after time.  The larger diameter rivets usually give off a little puff of what looks like smoke too, just to finish the show.  I don't know if it's actually smoke or what it is, but I love the process.

Rudder Trailing Edge

I bit the bullet and set the rivets on the rudder trailing edge.  The tape is supposed to hold the skins and wedge together while you rivet, but it really didn't work out that way. I'm not super happy with how they came out, but after licking my wounds and talking to some guys on the VAF forum, I learned that I'm in really good company and most people have very similar experiences on the trailing edges.

The trailing edge on whole is within the spec in terms of being straight, but the skins pillow a bit in between the rivets (and sometimes at the rivet too if the dimples and countersunk wedge don't sit right).  Consensus is that this happens all of the time if you just follow the Van's directions.  It sounds like significant experience and learning through error are the only ways to correct this.  Most people suggested just leaving it, but some have gone the extra step of filling the gaps with fiberglass/epoxy and sanding smooth.  I'm setting it all aside for now and will figure out what to do down the road when I work on all of the fiberglass and body work for the plane.  As with most aesthetic items so far that bug me, this is yet another one that will only be noticed by someone looking for it specifically.

Following the trailing edge, I finished the leading portion of the rudder. In order for the rudder to sit within the recess of the vertical stabilizer, you have to bend the skins and rivet them together to form a curve.  I used a 1" broom handle taped to the skin and rolled the skin until it was close to the desired shape.

I made the mistake of assuming that the #40 prepunched holes in the skins were the right size and match drilled them all at that size.  Then, as I usually do, I referenced the plans to see which rivets to grab.  Oops.  Turns out they are 1/8" rivets, which means I had to redrill at #30.  Not a big deal, but one of these days I'll have to remember to look 2 steps ahead before finishing a step.

With that, the rudder is pretty much done.  The only items remaining are to attach the bearings that marry it with the VS, but I'll wait and do all of that when I put them on the fuselage.  I'll also wait and do the fiberglass tips down the road once the plane is largely finished.

Next I'll tackle the elevators.  I'm a little nervous about the riveting on the elevator spars just because of the access and the pre-bent skins, but from what I'm learning from all of the other problematic areas I've hit, it's unlikely I'll do any worse than others who have gone before me and still have flyable airplanes.  I'm definitely my own worst critic.  Even when I know a mistake I've made is really no big deal (like slipping off a rivet and dinging the metal next to them), I shake my head because I know I've made an avoidable mistake.  I suppose it's healthy to have that mentality when building a plane, but I need to learn to just smile at goofs and count it as part of the experience.

Rivets In Tight Places

I got my new 4" no-hole yoke attached to the squeezer so I could tackle a few of the rivets in tight spaces.  In general, the yoke worked really well, but even with it, there were rivets I couldn't squeeze because the space was too tight.

I think the lesson for today is that if the manual says that blind rivets are an option, there's a very good reason they're an option!  Getting into the last hole of the rudder ribs may have been possible with a very small bucking bar, but the end result would likely be iffy at best.  So from here on out, in all likelihood if a blind rivet is allowed, I'll probably use it.  It's funny how some builders seem to think that if you use a blind rivet you're less of a builder.  To me, it's a reasonable tradeoff of time.  If the hole in the rivet bugs me, I'll just fill it before I paint, but honestly, I don't think it'll even be noticeable.  You can see the pop rivet next to the sharpie "R" in the picture.  There are a lot of different types of blind rivets specified, but these specific ones are for dimpled holes, so they are flush, just like a solid rivet would be.

On the second side of the same rib I found that I had to use a blind rivet in the last 2 holes vs just the last hole on the first side.  That's because once the solid rivet in the 2nd to last hole was set, it created a smaller space that the no-hole yoke no longer fit in.  Again, these are going to be at the top of the rudder though, so depending on what color of paint I end up with, probably next to impossible to see.

The last bit of riveting on the skeleton of the rudder was to attach the rudder horn cover.  I was able to get 3 of the 4 rivets to the skin squeezed, but my longeron squeezer wasn't long enough to get the very back one.  Again, blind rivets are allowed, so that's what I used there.  For the 3 rivets that are at the aft edge of the cover (connect the tongue of the cover to the rib - pointing to the left in the picture), Van's calls out solid rivets with the option of blind rivets.  Because I didn't install the cover until after closing the skins, there is no way of accessing the back side of these rivets.  Had I put this cover on part-way while I was building the skeleton, I could have used solid rivets I guess.  I just left it off because I knew it needed to be riveted to the skins.  So maybe on airplane #2 I'll remember that I could attach this piece earlier using solid rivets, but for this plane, the acceptable blind rivets will do just fine.

Now for the trailing edge.  This is slightly nerve wracking since I need to get an arrow straight trailing edge with less than 1/10" of variation from straight at any point over the 4' span.  I'm sure it'll turn out to not be that big of a deal to do, but it's a brand new kind of task and riveting.  To start, the recommendation is to adhere the wedge between the skins vs just riveting right away, which can cause warps.  Van's used to recommend using proseal to stick the skins together to the wedge, letting it dry while clecoed to a piece of aluminum angle (to keep it all straight), then rivet after it set up. They now recommend using 3M VHB tape instead since it's a lot less messy.  After seeing the tape, it blows my mind that it can do any good.  It's a double sided tape that is so thin I was questioning if there was anything on the backer paper.  I cleaned the wedge with acetone and stuck the tape down on each side.  

Once the tape had set for about 20 minutes (supposedly gets stronger the longer it sits), I slid the wedge between the trailing edge of the skins and pulled about an inch of paper off the bottom side of tape.  I can't remember if I mentioned this yesterday, but I had prepared a piece of aluminum angle by drilling holes into it that matched the spacing on the skins. I clecoed through the skin, wedge, and aluminum angle in the last hole on each end of the skin, then peeled back the rest of the tape.  Then I repeated the process with the tape on the top of the wedge.  Once the tape's backing paper was completely removed, I clecoed all of the holes to the aluminum angle.  I'll let it sit overnight and hopefully the tape will do it's job and help to keep the skins in position and straight when I rivet tomorrow.  Fingers crossed.  It's really hard to believe that tape does anything, but apparently it's pretty amazing stuff once it gets bonded. 

Rudder Trailing Edge

I haven't been able to do much more on the rudder or elevators until I get the new 4" yoke.  That has me twiddling my thumbs a little bit, but now that I have everything primed, I went back to finishing the rudder.  The last piece (aside from finishing the rivets I need the yoke for) is to do the trailing edge.  I countersunk the holes in the wedge that goes in between the skins at the trailing edge.  Doing this by hand is known to be problematic because the material is thin enough that when you do the second side the hole enlarges and the countersink flute wanders.  Dad and I had set up the drill press before he left, angling it so that the cage matched the angle of the wedge.  This worked great.  It was very easy to countersink the wedge.

It's too late to get any additional work done tonight, but as I'm writing this, the UPS man brought my new yoke.  This is a 4" throat, whereas my biggest throat up to this point was 3".  It also does not accept a die on the upper nose.  It is solid, meaning you can squeeze rivets right up against the nose, allowing squeezing in tighter spaces.

Primer Day

Priming itself is fun to a certain degree, but the prep work to get to that stage sure isn't.  It looked like I had a rare day in the 60's today, so I figured I'd better jump on it while I could.  The problem was it was extremely windy.  I set up relatively close to the garage to try to get out of the wind at least a little.  I spent a few hours acid etching and scuffing parts, rinsing, and drying.  This portion of primer prep gets boring really quickly.  I may have to figure out a new process going forward, otherwise I'll start to dread priming days.  I know of some guys who scuff up parts immediately after match drilling and before dimpling (scuffing after dimpling is really rough on fingers and scotch brite pads), mostly to break up the monotony of the task.  If you go that route, you still have to do a quick scuff on priming day to get rid of the oxide that has formed, but it should be a lot easier since the physical scuffing part is already done.  I may give that a shot on the next elevator.

So the parts got scuffed and dried just as the wind doubled down and the clouds started looking a little more threatening.  The kicker with scuffing and priming is that once you start, you really need to finish.  It's too much to set up and get ready only to have to tear it down, clean, and set it all up another day.  Needless to say, these parts are not the prettiest looking spray job!  Falling leaves, bugs, and an occasional rain drop made for an interesting surface finish.  It's fine for interior parts though.

I was down to having just the skin left to prime when the rain came.  Not heavy at least, but enough that I had to move things even closer to the garage under the eaves.  I was determined to finish.  Because the skin is a clamshell, I had to wire it open in order to spray it.  That worked fine.  Everything is done and ready for assembly now.  At least this elevator.  It won't be long until I have to do another priming day for the left elevator.  I have a feeling my options for spraying outside are probably very limited at this point though.  I' guessing I'll have to set up inside the garage next time.

Elevator Ready for Primer

Not much to show for a couple of hours of work tonight.  I think I've built and disassembled this elevator at least a half dozen times.  Just as soon as I think I've caught everything they neglected to mention in the plans and take everything apart for the "final time," I find one more hole that needs to be addressed or something.  This section of the build gets nodding smiles when it's talked about on the forums, so at least I'm in good company.

The bottom skin/spar has the option of using either pop rivets or solid rivets.  After a lot of reading and research, I've landed solidly in the pop rivet camp.  Sure, I prefer the look of solid rivets, but since only people laying on their backs looking up at the elevator will see these rivets, I just don't care enough to put the effort in for solid rivets.  There is literally no way to buck these using normal tools because the spar flange is open on the forward facing side (so you can't reach in the trailing edge side to hold a bucking bar).  People who do decide on solid rivets usually end up fashioning a 4 foot long bucking bar that they try to slide between the leading edge and spar.  No thanks.  Sounds like a nightmare.  I'll trade some pop rivets to save what I'm guessing is a couple of hours of riveting and cussing.  I'm very unlikely to care what rivets are in the tail when I'm done and flying.  So anyway, I bit the bullet and drilled the larger holes into the spar for the pop rivets (1/8 vs 3/32), so there's no turning back now.

After taking everything apart for what I desperately hope is the last time, I finished deburring everything that I hadn't done already.

The last thing I needed to do tonight was dimple the holes for the spar.  Given that these are right at where the skin is rolled, it's not exactly easy to handle it all using the c-frame dimpler.  I started on the bottom, knowing full well that I'd probably discover a technique issue that I'd rather learn about before moving to the top skin.  Sure enough, I had a little trouble initially.  There's a hesitation to open the skin up far enough to really flatten out the area for the dimple die, and that cost me a few "smilies" in the line of spar holes.  It's hard to see in the picture, but where I marked is where I wasn't super happy with how the dimple die contacted the skin.  The dimple is good, but the die dug into the skin a little bit because the rolled edge wasn't pulled down and away enough.  Not a big deal, and truly probably not even noticeable, especially once paint goes on.  You can see in this picture the 1/8" holes for the blind rivets vs the 3/32" holes in the rest of the skin.

I (hopefully) learned my lessons on the bottom skin and moved on to the top side.  My biggest lesson was that I could really flatten the skin out an awful lot without causing any damage.  For this side I put a lot more effort into holding it down with the palm of my hand while I also held the dimple die in place with that hand.  It's a little awkward, but doable.  I only had a few very small uneven hits with the dies on the top surface, so am pleased with how it came out.  The top skin gets riveted onto the spar first while there is still open access, so it uses all solid rivets, hence the 3/32" holes on top for the spar.

Aside from needing to dimple a couple of holes in the tips of one of the ribs that I didn't get to tonight, I'm ready to prime.  I didn't do those holes because they are in an extremely tight location, so I need to switch gears and either use the pop rivet dimpler or the hammer/dimple approach like we did on one of the earlier ribs from the vertical stabilizer.  The weather is now solidly Seattle fall weather, so I'm going to have to figure out priming in colder/humid weather.  It's unlikely I'll be able to spray outside, so I'll have to sort something out for doing it indoors.  That's a huge reason why I purchased the EkoPrime product - much less toxic since it's waterborne and doesn't use the nasty carcinogenic stuff.  Spraying it inside will be much less of a concern if I need to do that over the winter.

Of course, tomorrow I have to make a trip to the aviation aisle of Home Depot.  I need to pick up a piece of aluminum angle to use when riveting trailing edges. In order to make a straight trailing edge using the wedge that goes between the skins, you need to fix the wedge to the skins using either tape or proseal (I'm using the heavy duty 3M double sided tape they recommend) and fasten it to a straight piece of angle for a few days while the stuff cures.  Then you can rivet with less concern of it warping.  Van's says to shoot for less than 1/10" of wave, since more than that can cause differences in handling.  

Once again, the order Van's has you do things in for the elevator is just strange.  They have you prime everything and rivet most of it together before starting on the trailing edges, meaning that you have to match drill, dimple, countersink, etc in the skin which has already been primed.  So I'll probably have to touch up some scuffed up parts before riveting the trailing edge.  I know it's nothing to worry about, considering a completely unprimed plane would still likely outlast my lifetime.  Given that this plane will likely live in the Pacific Northwest for a while though, and to top it off may not have a hangar since those are insanely rare and expensive around here, I am just trying to give it the best shot of staying in good shape for as long as possible.

I have a few days off from work, so hopefully I can hammer out the right elevator, finish the trailing edge of the rudder, and get the left elevator started by the end of the weekend.  If all goes well, I should be starting the wings sometime in the next month.

Sub-Par Instructions

There's not much to show or explain from the last couple of days.  I'm convinced that Van's handed off the instructions for the elevators to the new intern.  Things are not only out of order, but many sections just don't make any sense.  For such a simple assembly, I've spent more time scratching my head than actually building the last two days.

I fit and match drilled the reinforcement plates to the spar, then clecoed and match drilled the end rib.  

The end rib has to be riveted to the spar right away in order to do the rest of the fit.  I deburred and cleaned up the rib and then hit the mating surface of the rib and spar with some self-etching primer.  Those insanely hot halogen shop lamps come in handy when you want to dry primer.  Only 30 seconds or so under the lamp and the surfaces were dry enough to work with.  The rib has to be riveted on with a flush head rivet on the side of the spar so the control horn will fit, so I dimpled it all.  I know some people countersink the spar instead, but it's thin enough that dimpling worked fine.

Following the instructions, I then clecoed the rib and spar to the skins, only to discover that the step they want done next can't be done with the spar installed in the skin.  So out came all of the clecos so I could match drill the control horn to the spar and rib.  Then back it goes!  Looking ahead in the instructions, I've noticed that they never mention the top skin surface.  The top and bottom skins are attached differently, so I have to figure out the order of operations based on the plans so I don't get backed into a corner once I start riveting things together.  It sure would be nice if the instructions were just a tad better for this part of the build.  It's funny, because in the manual Van's says that the elevator is the most messed up part of the build for new builders.  I'm not sure that they realize how they're contributing to that stat with their iffy instructions.  I'll get it sorted out, but it'll just take longer than it should.

Right Elevator Dimpling

Time to deal with the pre-bent skins and figure out how to dimple them.  Because they are clamshells, there's no easy way to mange the c-frame dimpler and use it like I normally would.  I pulled off the blue film and tried a few methods.  While I was trying to sort out how to use the c-frame, I went ahead and hit the holes around the edge of the skin with the squeezer and also dimpled the stiffeners with the squeezer.  I had heard that some people use the pop rivet dimpler, so I gave that a shot.  It works, but it's a slow process and doesn't make dimples that are quite as crisp.  I can see using it on a hard to reach area, but don't think I want to use it unless there's no other option.

Back to the c-frame I guess.  The only way I could really manage things myself (not having someone to hold the skin open) was to reverse the dimple dies and use the male die on the upper set that gets hit with the hammer.  I prefer to have the male die on the bottom plate just because it makes locating the hole and keeping things aligned a little easier, but not much choice this time.  Using the c-frame like this let me open the skin and keep it open by sliding it down the bench legs.  It took forever doing it this way, but ultimately worked okay.  I did have two holes near the bend that I screwed up because I didn't keep the skin flat enough when I hit the die.  It created a ding at the edge of the dies.  Lesson learned.  At least it was on the bottom side.

After I finished dimpling, I moved on to the counterweight ribs and counterweight skin.

Right Elevator

I'm waiting on my new yoke to finish off the rudder, so time to switch gears and start working on the elevators.  These are built similarly to the rudder, using mostly stiffeners instead of ribs as the internal structure.

Just like the rudder stiffeners, Van's supplies a big bundle of angle that has to be cut down to the correct length and shape.  For the rudder, all of the stiffeners were different sizes, but for the elevators they're mostly the same.  The one exception is on the left elevator, where there is a section of shorter stiffeners/skin to make room for the trim tab.  I went ahead and cut, shaped, and deburred enough stiffeners for both the left and right elevator (minus the short ones).

The simple step of match drilling the stiffeners to the skin is complicated by the fact that the skin comes rolled at the leading edge.  A board, clamps and some rope worked relatively well, but I can see that back riveting the stiffeners in is going to be pretty awkward.

Once I figured out how to keep the skin open, I got both sides of stiffeners in and match drilled. The bend at the leading edge makes it difficult to get the stiffeners to lay flat while the skin is open, but it's doable.  It's amazing how such a flimsy piece of sheet can get so rigid with the addition of the stiffeners.  Completely done with the match drilling, I pulled it all apart and deburred the stiffener holes.  I finished deburring the outside of the skin as well, but landscaping chores cut work on the plane short, so I'll deburr the inside and edges of the skin another day.