Nov 5-6 -- Finish Empennage

Last post on July 4, and in between was pretty much all travel. Around the world sounds like the adventure of a lifetime, until you do it twice in ten months...

This weekend was back at the project, and it was momentous! Finished work on the empennage, or at least as much work as can be done right now. Fiberglass tips and final assembly come at the end of the project.

Built trim tab #3, which came out great, assembled the elevators to the horizontal stab, and drilled an important hole in the elevator horns.

But not until a friend with a flying RV came over to eyeball my work. As per one of the photos below, alignment was off a bit once parts were assembled. Everyone told me that this is normal, although that seems odd in a CNC environment.

In order to drill that hole thru the center bearing, I used some punches from Harbor Freight that fit precisely into a wide variety of hole sizes. In this case it was a 1/4" pin that created the dimple to use as a starting point for the drill. After a #40 pilot hole, worked my way up thru a #30 to a 1/4" bit. The #30 intermediate hole included part of my finger, although I decided that assembling the finger at this time might be inconvenient.

I also realized how woefully dull my inherited drill bits are, so I ordered $300 worth of new cobalt drill indexes -- the first time in my life that I actually purchased all the bits new as a set. Probably should have done this years ago.

All parts now hanging on the garage wall, and it's time to start on the wings.

Total Time this weekend: 19 hours

July 4 -- Build Tool to Insert Elevator Bolts

The instructions say that it's time to attach the elevators to the horizontal stabilizer, in order to check clearances and drill another hole. Yikes, this whole assembly process is a royal pain, and it took lots of searching online to see what others did. So here's a post on a tool that I built, and two other tips. Hope it saves others some time. (Sorry, no help on the agony bit...)

First, it's tough to slide a bolt thru the holes because it's tough to align the parts. Someone else posted a tip that allen wrenches make a great pin because the 90 degree bend acts as a handle. Even better, use a small one first, then guide a larger one into place. See below for a photo of the larger inserted into the assembly.

Even with this trick, it's still a pain to insert the bolt. In fact, I was speaking like a pirate while I tried with no success... Then I saw a tool that Dave Parsons built for his RV project. Mine is less refined, but works like a charm! I flattened out a couple of leftover pieces of aluminum that began life as stiffeners. The 1" belt sander worked well to cut a slot and generally shape things, followed by some metal forming in the vise. Wow, does this thing work well!

Finally, it was still tough to slide the bolt all the way home. Cleco pliers solved that!

Next up is figuring out what's rubbing. I am fairly certain that the rubbing comes from a rivet shop head that stands too tall. But not much time this weekend for building. Squandered the available time flying, bike riding, and refinishing the deck. What a spectacular Fourth of July!

Total Time: 3 Hours

Jun 30 -- Installed Counterweights

Not much to say. Some trimming to clear rivets, bolted 'em on. Bigger news is that it now sounds like all of August except for a few days will be spent traveling for business. Not good for enjoying summer or for build progress.

Like everything, tonight took way longer than it sounds like it should have.

Total Time: 1 Hour

Jun 29 -- Cut Elevator Counterweights

Tonight was more thinking than doing... Cut 4 lead counterweights for the elevators. Once again my investment many years ago in a power miter saw paid off.

The weights will still need minor tweaking in order to fit past rivets; however an initial try-fit indicates that the initial cuts are right on the money. :)

Total Time: 1 Hour

Jun 18 -- Trim Tab & Left Elevator

What you don't read here is also an important part of the project. Everything has been on hold because the drill press needed repairs (the chuck kept falling off). Took the spindle to a local machine shop; however when I got the part back the chuck wobbled slightly. Not good! EBay solved the problem after some off-EBay dickering with a dealer.

Per an earlier post, the first run at a trim tab hinge was all boogered up. So this time I used a #41 drill bit and a rivet fan to carefully lay out and drill the hinge holes. At least with this rivet fan a #41 bit is perfect in the rivet fan holes, as you can see in the photo below. Using the rivet fan really helped clean up "eyeball" variances from hole to hole. Simply clecoed then ends, then drilled holes in between, using the rivet fan to guide the drill press directly.

Used ProSeal to glue some foam ribs inside, and also carefully riveted the tab together. It's sitting in a corner for a week or so while the ProSeal sets up.

Next I closed up more of the left elevator and also glued up the apex wedge in its trailing edge. Hard to believe how much day all of this ate up, but a great way to spend a rainy Saturday.

Total Time: 5 Hours

May 30 -- Left Elevator and Trim Tab

Been forever since I worked on the project. The Luscombe annual, followed by a trip to Europe for close to a month conspired... And now a deck refinishing project lurks. Couldn't finish it last summer thanks to neck surgery. Not to mention that the drill press is in pieces for a long-overdue overhaul.

At any rate some modest progress.

On the elevator, I drilled the trailing edge wedge, also known as the apex wedge. Learned a lot on previous attempts, so this time I used angle iron for the trailing edge to keep everything lined up. Also used the new battery-operated drill for countersinking. Slow speeds really help with control.

The trim tab is starting to come together, although I did have some issues thanks to dimpling. See the photos for where the dimple die interfered with the bent tab at the end of the trim tab. Had to do some repairs, so back into the clamping blocks...

I also went off plans with standard rivets in place of the pop rivets on the plans. Hoping that there are no issues when it comes time to squeeze them (doubt there will be as long as I perform this operation before inserting some internal foam ribs). Also dimpled and primed the forward trim tab spar.

Hard to believe; however this was:

Total Time Today: 5 hours

April 12 -- Elevator Trim Tab

Posts have been sparse lately, thanks to work. Silence cloaked what activity did occur, and perhaps that is just as well.

Picked up a spare elevator trim tab skin while at Vans to get the wings. At the time it looked to be wasted money; however statistically an extra skin is a good investment.

Sure enough, the first attempt was a fiasco when I bent the tabs at the end. Issue was that I pranged the aluminum in every conceivable way while bending. Some (OK a LOT of) research online turned up that (a) the block recommended for forming the bend should be harder than pine, and (b) there is no such thing as "tight enough" when clamping the block down.

Fortunately(?) the mess known as our garage has some hard maple stock in it. Karin's childhood bed frame, to be precise. A piece of that maple made a great forming block, with more maple affixed to the sides of the wood to keep everything aligned. Then three screws in the bottom of the block served to clamp the assembly, and a humongous C Clamp worked on the other end. The genesis of this approach came from this page -- about halfway down.

That's a 10 degree angle in the maple, and I used a jointer to make certain all was super smooth. (The jointer is another bit of clutter in the garage.) The pieces tacked on the side don't quite touch the bottom of the block, in order to ensure that there was not any tilt induced by alignment issues. This setup took me 4+ hours to build, including time spent on some bad tries.

Some thoughts for others who may be reading this blog post as they consider their own construction project.

• Make certain that you clamp tightly and precisely. Bend the bottom tab first, then the top tab over the bottom. It's easy to miss in the instructions; however the bend line should intersect the middle of those "u" notches on the aluminum. Consider that the top bend will be over the bottom one, so make certain that the first one is spot on.
• Vans says to use a rivet gun to finish off the bend. I found that was a way to scar the aluminum. Besides, a block of maple and a hammer are all that are required.
• My bending brake (per Vans instructions) was made with wood from Home Depot. It was wet, green, and warped. Stuck it thru a planer to true it up, then left it on top of the table saw for a week. Result was a rusted table saw top, and wood that warped again. You can draw your own conclusion...
• That same brake will be used later for (longer) ailerons. Word is that I should have purchased wood long enough for a six-foot brake. I didn't, which is either good or bad, depending on your thoughts about the previous point.

Total Time: 10 hours (includes the bad trim tab not shown here)

Click on photos for a close-up view.

Mar 5 -- Elevator Trim Tab

Lots of "enabling" work today.

Started by melting plastic off the outside skin of the elevator, then drilling and deburring both the skin and trim tab rib. Didn't even bother with clecos before match drilling, because when I lined parts up it was obvious that once again CNC had everything spot on.

But most of the time was a matter of cutting foam for ribs and also some wood for forming blocks. Once again the miter saw came in handy with its clean cuts. So did the table saw.

Total Time: Can you believe that I burned over 4 hours on this?

Feb 26 -- Rivet Left Elevator Bottom Skin

Technically this is two days, because a couple of days ago I riveted the gusset on to the rib. What a pain -- over an hour and about 6 drilled rivets later there were 2 installed rivets. Some fool posted on their site that out of 15,000+ rivets, they only drilled out 200 or so. Calling BS on that stat...

Today was just a bit of time on the plane. Riveted the bottom skin to the E-901 spar, then attached the Counterbalance assembly to the spar. This is the reverse order of the instructions, and works out better. One pair of rivets buried way down inside connects the counterbalance assembly directly to the spar. I used (gasp!) pop rivets. Out of site, just as strong, and the result is a much better grip than trying to get in there and buck a standard rivet.

Next up will be the trim tab spar. But I need to go heads down on work for a week or so, meaning that all progress will stop for now.

Total time: 1.5 hours

Feb 23 - Backrivet Lower Stiffeners, Install Trim Servo Reinforcement Plate

Tonight I installed the nutplates on the trim servo reinforcement plate, then installed the plate on the lower skin. Next up was backriveting stiffeners to the lower skin, with some NAPA gasket material behind them to dampen vibration that others report causes cracks in the skin.

Total Time: 2 hours

Feb 22 -- Re-do the Elevator Trim Mounting Plate

The first run at this plate didn't go so well: see the "before" version on the left in the photo below. In my attempt to counter sink the holes for nut plates, the countersink bit walked and ruined the piece by decorating it with ovals.

The replacement part showed up today. This time I enlarged the #40 pilot holes in the part, and then drilled #40 holes into hard maple, in order to provide a hole that would prevent the bit from walking. What a difference!

Stopped for the evening after counter-sinking, deburring, cleaning, painting, dimpling.

Total Time: 1 hour

Feb 21 -- Rivet Spar to Left Elevator Top Skin

Tonight I riveted the E-902 spar to the top skin of the elevator. About 20% of the rivets could be squeezed; the rest were accessed by clamping the bottom skin to the table and then spreading the top skin so that it was possible to get a bucking bar in there to buck the rivets, two at a time.

Backriveting doesn't work here, because the skin flexes and it is not possible to keep the rivets flush against the steel backplate.

I'm learning to cut objectives down into smaller sessions. Get better results when I slow WAY down!

Total time: 1.5 hours

Feb 20 -- Backrivet Stiffeners

Back-riveted the stiffeners to the top skin, with ProSeal under them to act as a vibration absorber. Was able to rivet a couple of lower ones too, before the ProSeal was too set up to be usable.

Bunch of rivets are going to need to be drilled out and re-set, because the shop heads are messed up. tough working conditions in there, trying to spread the skins enough to rivet. Don't want to clamp them open, because that damaged the other elevator.

Also cut down some angle iron into flat steel plates to use for riveting in tight places. The EAA Website has a great video tip on how to do this.

It got exciting though, because I did the cutting on the table saw, and the sparks ignited about 8 cubic feet of sawdust inside the saw base! Was time to clean it out anyways...

Total time on the plane: 1.5 hours.

Feb 19 -- Dimple & Prime Left Elevator

Weekends are priming days, because there's light outside (and I get into enough trouble about the smell of fresh primer just from bringing the parts back into the Garage).

Today I primed the stiffeners after masking off the side that will face the elevator skin. Plan to use ProSeal between them and the skin, in order to prevent vibration caused by cracking.

Next up was dimpling the skin, with Karin's help. Then I scuffed the inside skin, cleaned with Coleman fuel, and masked off areas where ProSeal will be applied. Oh, and of course primed the inside of the skin.

Some more drying time and riveting can begin.

Total Time: 2.5 Hours

Feb 17 -- Drill & De-bur Left Elevator

Van's replied to my email today to say that the stiffener issue from yesterday is a non issue. "Build On" was the message.

Tedium tonight... Drilled out all the holes in the skin for the stiffeners (the ones that officially need to be clecoed together and then match drilled). Per yesterday, I am counting on CNC fit to make things "just fit". History says that they will.

Next came manual de-burring of each side of each hole. At least it's done now.

Seems like some errors in the instructions for the next few steps on this assembly, so going to surf some other builder sites to see what I can see.

Total Time: 1.2 hours

Feb 16 -- Left Elevator Stiffeners

Continued work on these tonight. First I cut the majority of them down to the correct length for this elevator (they need to be shorter because the trim tab). As I cut each one to length I also tapered the rear edge of each stiffener to match the taper on the original (longer) ones. Doh! They don't need the taper! Gonna have to check in with Van's Aircraft to see if this is worth re-doing...

Also drilled the pilot holes in each stiffener out to #40. I didn't cleco things together first, because these CNC holes are so accurate that there's no point in aligning to match drill. Put another way, on the other elevator I did more damage via kinks in the skin when I tried to open it wide for all the stiffener work.

Next I scuffed the pieces with Scotchbrite pads (a lot easier than after dimpling), and finally it was time to dimple each stiffener.

Total Time: 1 hour

Feb 14 -- Left Elevator Stiffeners

Celebrated Valentine's Day in the garage. (We never celebrate it...)

Tonight I spent 45 minutes making stiffeners, which meant pulling off the protective plastic, cutting them, and deburring the edges. This elevator requires that most of the stiffeners be cut to a shorter length, but that was out of scope for tonight.

Total Time: 0.75 hours

Feb 13 -- Left Elevator

Match-drilled the spar, and ribs for the left elevator, then deburred, dimpled, countersunk, cleaned, dcuffed, and primed a number of parts. deburring is easy using the Scotchbrite wheel; albeit a bit tedious. (Dimpling is really tedious. And as you can see in the photo, lilac bushes are there primarily to hang parts from.

There is a doubler for a recessed area that holds the trim servo. I managed to make two oval holes while counter-sinking for nutplates, so a new part is on order from Vans.

Finally riveted together the counterbalance ribs. A bit ahead of myself there, because there is still a lot of work to do with stiffeners and the skin.

Total time: 7 hours

Feb 9 -- Start Left Elevator

Fixed one last rivet on the trailing edge of the right elevator, then started the left one. Actually, I did just a bit of work on the spar the other day (deburred the edges).

Tonight I pulled the blue plastic off the inside of the skin, and then used a solder gun to met strips off the outside where rivet holes are. Next came deburring the edges of the skin (wicked sharp!). Finally started clecoing parts together.

Only 6 weeks until I pick up the wing kit -- gotta get my butt in gear!

Total Time: 1.75 Hours

Feb 6 -- Right Elevator Trailing Edge

First things first. That epoxy on the trailing edge was an awful idea. What leaked out was hard to get rid of, it goobered up rivet holes, and didn't really adhere to the aluminum that well. OK, the adhesion issue was most likely my failure to remove primer from the subject surfaces...

Pounded in all the rivets, but frustrated and quit for the day. Will finish the rivets and making certain that it's straight with no epoxy in a fresh session. Suspect that 25% of the rivets need to be drilled out because the shop heads tipped over. :(

Did start on a bit of drilling and deburring for the other elevator while waiting for 24 hours on the epoxy...

Total time: 1.5 Hours