Hello my dedicated readers, er, I mean reader (thanks, honey)! This week we’ve decamped to Telluride for our annual Memorial Day getaway. While there’s no actual work happening on the plane, the break is giving me time to catch up the build log and post some (hopefully) interesting content (in between margaritas and jigsaw puzzles).
Too Big for UPS
The big news is that the wing kit finally arrived a few weeks back. I had many people ask how close the final shipment came to the estimate provided by Van’s. It was pretty close. I ordered it the first week of January and Van’s promised shipment within 16 and 20 weeks (they are now listing lead times in months–sigh). I knew shipment was getting close when I noticed the balance charge show up on my credit card. Then about a week later I got an email from the shipping company tell me I could call and arrange delivery. I thought it odd that I had not gotten confirmation from Van’s but then shortly thereafter I got a packet in the US Mail (how quaint!) giving me the details I needed, along with instructions on how to handle potential damages. I have seen some pretty bleak reports of damage during shipment and was hoping I would not have to deal with such headaches.
Fortunately I had no such issues when the shipment arrived.
I’m sure the driver had some questions about the odd-shaped crates but if he did he kept them to himself.
The driver was very accommodating and pushed the crates over the curb and up the driveway into my garage/aircraft factory.
After the rush of the delivery was over I realized I had made a tactical error in scheduling it for mid-week. In retrospect it would have been better to schedule it for Friday so I could have quit work and gone straight into inventory management. However, you shouldn’t attempt to build an airplane if you aren’t good at problem solving and, after thinking about my predicament for a few moments, I grabbed my laptop so I could take my remaining Teams meetings from the garage. I assure you I was definitely, sort of, paying attention.
One thing that is not on the inventory sheet is the shear volume of packing paper Van’s uses to protect the valuable cargo. I was pretty sure I could have packed a small, single family home with everything that was left over, as you can see in the time lapse video below:
Inventorying the kit is a critical first step as you only have 30 days to inform Van’s of missing components and get them shipped for free. After that you pay the bill. I inventoried the large/aluminum parts as I unpacked them but there are several bags and sub-kits that require more careful study. In the end everything was accounted for with the exception of some backordered flap nose ribs, some AN4 bolts (they shipped AN3’s instead), and 3 measly K1000-06 nut plates. I felt sort of bad for making Van’s send me 3 replacement nut plates as I’m sure I have some extras but, being extremely Type-A, I could not violate the mandate to tell them what was missed. I received the bolts and nut plates within a week or so.
You Can Have a Storeroom or a Workshop But Not Both
As satisfying as the unpacking and inventorying was it left me with the dilemma of what to do with all the new pieces parts (not to mention the completed empennage) such that I would have room to work (and park my truck at night). I had already used a good chunk of the wall space for some decorative aluminum art pieces:
And I’d cleaned off enough junk from some storage shelves for the smaller pieces:
That left the problem of what to so with larger wing skins and the massive spars. My first thought was to hang the leading edge skins from the ceiling. I bought a hardwood closet rod at Lowe’s and fashioned some plywood brackets but, after attaching the brackets to the ceiling discovered the skins were just too heavy and cumbersome to safely get them up there. Instead I opted to reposition the “elevator wall art” so I could hang the skins alongside):
For the wing skins I decided to use the space along the wall I normally try to keep clear do I can open by truck doors. I used some structural pipe, hose and pipe clamps, and the sides of one of the crates to fashion a shelf of sorts that hold not only the wing skins but rear spars, j-stiffeners, and other long parts:
The reason I chose to mount the shelf off the floor was that I need room to store the wing spars. While it won’t be too long before the spars are part of the larger wing structure I did want a way to tuck them away during the initial construction phases. The solution I came up with was to attach some casters I had on hand to the shipping crate. That way I can roll them against the wall when I need to:
That left only the empennage, which had been occupying one of my rolling workbenches for the past several months. I had already decided it would live on the ceiling of the garage. The question was now to get it there. I thought about purchasing a manufactured solution like the one I use to store our Christmas sleigh (don’t ask–long story) but these are a bit overkill and expensive for what they are. Therefore I decided to try to roll my own solution.
I had previously fabricated two cradles to hold the empennage and so started by building a frame out of 1×3 boards and some plywood gussets to which these could be attached:
I bolted eye hooks at the corners and to the ceiling joists with the idea that I’d use rope to hoist the whole enchilada skyward and then secure it with some surplus light fixture chain I had on hand. After I trial run with ropes passed through the ceiling hooks I discovered the whole thing was too heavy to lift, even though most of the weight was surely the wood, not the aluminum. In the end I decided to add pulleys to both the frame and the ceiling to fashion a rudimentary block and tackle system. That provided the leverage I needed and, for the first time, at least part of the airplane took flight:
The empennage just rests in the cradle so to keep to sliding out and ruining both part of an airplane and two cars I threaded a bolt through a length of chain and fitted it to the tie down bracket. In the end I was pretty happy with the result as will be easily to get back down if I want to work on some of the remaining tasks.
Now, in the immortal words of Robert Irvine, “Let’s get to work!”
I have a problem. I’m impatient. And I have a short attention span. And, doc, when I lift my left arm really high I get this pain… Oh, right. The build.
With the wing kit ordered (Happy New Year 2021 to me!) I got obsessed with planning out the exterior lighting since a good chunk of it goes in the wings. I had researched various options from different suppliers with different strengths/weaknesses but really wanted a complete solution from a single vendor if at all possible. Then I learned of FlyLEDs.com. It’s an outfit focused in the RV market and apparently run by some Aussies (so points for that already) and unlike most (all?) other vendors doesn’t sell you something you can just bolt directly into your plane. Sounds awesome, right!
FlyLEDs really embraces the whole “amateur-built” concept by making you finish the build on the lights. (You’re building a whole airplane so how hard can this be, right?) Specifically they sell you the electronic components (circuit boards, LEDs, resistors, etc.) and you solder them all together. Now, I am old enough to remember (a) when Radio Shack was a thing and (b), in particular, Radio Shack’s “Science Fair 100 in 1” Electronic Project Kits. These were ingenious “educational toys” that allowed you to create a variety of electronic circuits by connecting components attached to a large board using wire and spring connectors.
I was particularly drawn to circuits that blinked or buzzed. I recall there was a basic VHF radio circuit included but I never remember ever getting that to work. This nascent interest in electronics caused me to own a basic soldering iron as a youth (though what I used it for is now lost to my ever aging memory) as well as a resurgent interest as an adult in the much trendier sounding hobby of “making”. This, of course, required the acquisition of a “much nicer” soldering iron (in fact a soldering station!) as well as enough microcontrollers and other components to start my own “shack”:
As you can see from the photo I had grand ambitions to build all sorts of internet-connected gizmos with sensors, displays, etc. In the end it mostly just fed my curiosity, though I did create a motor controller for a home-built TV lift and a cheesy Halloween special effect. Still, it gave me the confidence to tackle the FlyLEDs project without much hesitation.
Choosing a Lighting Option
FlyLEDs has a few different options to choose from when it comes to position indicators, strobes and landing/taxi lights. One of the primary choices to be made is whether to mount landing lights in the wingtips (integrated with the position/strobe lights) or in the wing leading edge. The integrated solution sounded clean and cool but I had heard that some traditional lighting options had issues with being obstructed by the forward edge of the wingtip. Plus, the limited space means the landing lights are not the brightest FlyLEDs offers and, if your going to do it yourself you might as well do it bright! So I opted for FlyLED’s “Original” wingtip light kit, which comes with complete with position lights, strobes and a controller board. I then added their tail position/strobe light as well. With this decided I felt “well positioned” to make the next choice.
Having decided to go with leading edge mounted landing lights there was really only one choice–for me anyway–FlyLED’s “Seven Stars” landing lights. These are their top of the line offering where the light level “goes to eleven” (or maybe seven…I’m not sure). Obnoxious? Perhaps. But they must be bright since they barely fit in your hand:
As an Australian company FlyLEDs does resell through Flyboy Accessories in the US but I decided to order directly from Oz to perhaps give the folks a bit more margin. (Plus the thought of the shipment potentially getting hung up in customs really excited me!)
Delivery and Unboxing
To my chagrin, US Customs decided to allow the heavy and obviously suspicious package through and it arrived in a week or so after ordering:
The contents were packaged well for the journey with ample bubble wrap and lots of little zip-loc bags of electronic components:
The kit includes all the lighting components plus DB-15 connectors, back shells and pins, thermal grease (for the numerous heatsinks), and even a length of solder!
Wingtip Light Assembly
The instructions that come with the kit are quite good so there’s not much I can add in terms of tips and gotchas. I will say, though, that for best results you should be somewhat proficient in your soldering technique, in particular getting the heat transferred from the tip of the soldering iron into both components you are trying to solder. This promotes good solder flow and clean results. The fact that some of the kit components are rather large can make this tricky.
One thing the instructions recommend is to test fit the large wingtip circuit boards to the wingtips and trim as needed. Of course, I had no wings yet but wanted to get started anyway. (Did I mention I’m impatient?) If I end up having to trim the boards after assembly I’ll just be very careful. In truth I’m not that worried. There are not that many (or fragile) components that need to be soldered on.
Assembly is quite straightforward, solder the LEDs, solder the big power resistors, solder the wire terminals, connect the two halves with ribbon cable. The position LEDs come in red and green (obviously) but it’s difficult to tell them apart just by visual inspection, though they come in separate bags. Take care not to mix them up. Helpfully, the circuit boards come with colored labels that you can remove after assembly;
The LEDs went on easily, despite the strobe LEDs being quite beefy, and the requirement to smear some thermal grease on the back side of each:
When soldering the power resistors the instructions state to leave some clearance between them and the circuit board to facilitate airflow/cooling. To get consistent spacing I used a couple metal rulers to establish an offset:
Once the LEDs and resistors are installed you can test the LEDs by connecting power directly to the contacts on the circuit boards. FlyLEDs recommends a 9-volt battery but I used my benchtop power supply. FlyLEDs warn that the units are bright and they don’t lie!
The only “gotcha” I came across was my own confusion trying to understand the instruction on connecting the two portions of each wingtip unit. The kit comes with a length of 8-conductor ribbon cable and instructs you “cut this in half” to create two pieces, one for each pair of boards. After dutifully complying I discovered that each piece was very short–too short, in fact, to reasonably allow for the two boards to sit comfortably at the roughly 90-degree angle required. I then realized I had cut the ribbon cable the wrong way–perpendicular to the wires instead of lengthwise. Argh…
I looked online for a replacement and only found options from my standard vendors (Mouser, Digi-Key, and Arrow) in the 1,000′ spool variety. Not wanting to start my own ribbon cable distributorship I opted for some 4-conductor cable used for RGB LED strips. Another reminder to measure twice, go get some coffee, measure again, and then cut once.
Controller Board Assembly
Assembling the controller board is nearly as straightforward as the wingtip boards but takes a bit longer due to the number of components. Taking my time to ensure high-quality soldering it went together in about a half hour.
One component I did not solder is the included DB-15 connector. (You can see the empty holes on the right side of the controller board.) I did this because I plan to install the controller board in a project box and want to mount the DB-15 there. This means at some point I’ll need to perform some tedious wiring, soldering and crimping.
Controller Board Testing
Once all the wingtip boards and the controller board was assembled it was time for a bench test. I used standard electronics hookup wire to connect the wire terminals on the wingtip boards to the open holes where the DB-15 connector would go. (I haven’t mentioned the tail strobe yet, because there’s nothing to assemble, but I wired it in as well.)
In truth you can perform a preliminary test of the strobe lights without connecting them because the controller board features 3 LEDs that flash in time with the main strobes in various patterns controlled by the DIP switches. Of course I wanted to experience the “full effect” (sunglasses at the ready) and even cobbled together a test rig using some 3D-printed parts:
As with any moderately complex electronics project everything worked flawlessly and exactly as designed on the first go! I’m kidding, of course. I discovered that the strobe lights on one wingtip were not triggering, even though the onboard LEDs worked fine. I retested the individual wiring paths and ruled out a bad connection on the wingtip board. And thanks to some explanation in the instructions as to how the strobes were controlled I was able to so some troubleshooting of circuits on the controller board using a multimeter. In the end, though, I was stumped and emailed the FlyLEDs support alias.
I got a reply from Paul at FlyLEDs (I suspect the sales, support and information emails all go to the same place) who was super-helpful in helping me troubleshoot the issue. He asked me via email to test a few things, which I did, even uploading some video of the errant behavior:
In the end we traced it to one of he IC pins not outputting the correct voltage during strobe sequence. This was highly unusual to say the least but, with the answer in hand, Paul graciously offered to have the team at FlyBoy send me a replacement. The great news is that since the IC is simple to swap out the replacement was super simple. This enabled me to stage a full-on test in my workshop, at night, with the window blinds pulled up–no doubt to the alarm of my neighbors.
Landing Light Assembly
Compared to the wingtip lights and controller, assembling the landing lights was quite simple since they don’t contain any electronics, other than those that come already soldered to the circuit boards. Construction consists mainly of assembling some 3D-printed parts and screwing them–and the main circuit board–to a giant aluminum porcupine–er, I mean, heatsink.
Each landing light (I ordered two) includes a large 3D-printed piece which holds lenses for focusing/distributing the light from the tiny (but very bright) LEDs, as well as a set of spacers that help position the lens holder. After separating the spaces from their web (very reminiscent of building plastic airplane models back in the day) the instructions state to bond them to the lens holder using acetone, which reacts with the ABS plastic. This fact came in handy when I managed to crack one of the lens holders. I simply slathered on some acetone and waited for it to cure.
The next step is to carefully snap in the small plastic lens cups and then, even more carefully still, snap the lens themselves into place. Each lens has a set of minute tabs that must align with gaps in the lens cups in order to fit securely.
You then screw the circuit boards to the heatsinks (after applying thermal grease) but I failed to get a picture of this step. All that’s left is to screw the lens assembly to the circuit board. At this point I discovered that the 3D-printed screw holes were a bit undersized (not uncommon in 3D printing) and some of the acetone-bonded spacers broke loose due to friction from the screws. However, I was not concerned since the screws are what provide the mechanical connection. I figured it would be no different then using loose aluminum spacers on other parts of the plane.
The finished result is two hefty pieces of kit. It’s hard to tell from the photo below because massive heat sinks are hidden by the circuit boards but, take my word for it, don’t drop one of these on your bare foot!
With the assembly done it was time to grab the sunglasses and test these behemoths. You’ll notice there are three connectors on each: GND, +12V and TAXI+. TAXI+ connects only the center LED to allow for “reduced airport denizen complaint mode” while taxiing at night. Apply 12V to the main connector and get ready for “Operation Suntan”.
As FlyLEDs says on their website, it’s hard to really illustrate how bring these lights are (amazing given the actual size of the LEDs). You’ll just have to take my word for it that I could have had some fun with my neighbors if I was that kind of person.
Now, when are those wings gonna get here so I can actually start building an airplane!
With the elevator debacle under control I decided to sweep up the metal shavings and switch gears to Section 12–empennage fairings–one of the few tasks left to do. Section 12 covers the installation of composite fairings to elevator, rudder, and stabilizer tips. The molded tips come as part of the empennage kit but some must be modified by building up one side with raw fiberglass cloth. The plans are extremely basic, describing a two-step process through very clean-looking engineering drawings. Little did I know how much “character building” would be involved in saga that unfolded over the course of multiple weeks.
Some time ago I had ordered the composite practice kit from Aircraft Spruce. I ordered the version that comes with Burt Rutan’s “Moldless Composites Sandwich Homebuilt / Aircraft Construction” (a $15.50 value!), figuring it would be useful to learn from the master. For some reason this SKU was backordered (the kit with just the raw ingredients would have shipped immediately) and so it didn’t arrive until early January. When it arrived I wasn’t sure I’d made the right decision since the manual’s contents weren’t any more illustrative then what I can find online through EAA and YouTube.
Regardless, the kit came with everything I needed to get started, including West Systems resin and hardener, fiberglass cloth, flox and micro, cups, stirrers, gloves and more. The accompanying manual suggests several practice projects with which to get familiar with the materials and processes but, frankly, none seemed all that interesting. I suppose back when Rutan wrote the manual (apparently using a typewriter and ink pen) someone reading it would be mystified by this “magic” process. Today, when composite manufacturing is practically live-streamed (not only aircraft, but boats, custom cars, and more) you (or, rightly, me) feels like they understand what’s going on.
And thus I decided to jump right in.
The tasks called out in the plans are fairly straightforward and go something like this:
Trim excess material to ensure the fairing will mate with the matching aluminum part.
Remove any excess epoxy/gel coat from the joggle along the flange perimeter.
Match-drill the fairings using the pre-punched holes in the aluminum skins.
Dimple the skins and countersink the holes in the fairings.
For fairings with an open side, enclose with three layers of fiberglass cloth and resin.
Attach the fairings (except for the lower rudder fairing, which waits until lighting is sorted) using CS4-4 blind rivets
There are several considerations that affect the fit and finish of the fairings. Rather than provide a chronological narrative of the process (since that would result in a 70-page blog post) I will present some highlights of each stage along with lots of pictures as well as my observations, learnings and frustrations.
Mis en Place
As when making a great meal, each stage begins with prep work. First you must sand off any resin/gel coat in the “joggle” where the fiberglass parts get riveted to the aluminum structure:
I tried using a razor blade for the first few passes but this proved cumbersome and not all that effective. I found using a flat file much easier. Just hold the long edge of the file snug against the corner and work it back and forth until it’s square. It’s a bit hard to see in the image below but goal is to get a nice clean edge so there isn’t a gap when you rivet these onto the metal components.
The next step is to trim excess material from each part. I used a Dremel tool with a cutoff wheel as well as painter’s tape and a reference line to reduce splintering.
One thing to be careful of at this stage is the width of the flange. The plans specify a nominal width but I would recommend making it a bit oversize and then sanding to fit. Otherwise you risk not leaving enough material to support the rivets (see below).
Match-drilling and countersinking the fiberglass parts is pretty much the same as when working with aluminum, involving clecos, #30 and #40 drill bits, and countersink cage.
Where Are The Dressing Rooms?
One thing you might have noticed in the photos is that the fit between the rudder and rudder fairing was, er, not great. In case you missed it, here’s a close up:
Oh, by the way, see that cleco right above the counterweight attach screw? The placement of that rivet hole is ambiguous in the plans drawings (note the lack of handy-dandy dotted lines below) but the text states you need to use an odd number of CS4-4 rivets and there does appear to be a hole drawn on the forward end so I assumed a rivet was needed there. If my rudder falls off because I misinterpreted the plans then now you know why.
In retrospect I would recommend prepping the fairings while assembling the tail section components so you can check the fit and attempt any adjustments. However, because the rudder was already built when I got the kit I didn’t have that opportunity. My first thought was to attempt to improve the fit with some composite treatment. (I had never used composites before and so assumed they were effectively magic materials.) After stewed on the issue, though, I decided to try to improve the fit of the aluminum skins. Keep in mind this piece has to line up with the vertical stabilizer tip fairing and I determined just slathering on fairing compound was not going to provide the finish I wanted.
My fix involved removing the rudder counterweight, filling in the top screw hole as well as the infamous 19th rivet hole with JB Weld epoxy (using duct tape over the holes), clamping the skins tight around the fairing, and re-drilling the holes.
You can see how much the top portion of the rudder skin squeeze together (about 1/4 inch) the final photo above. You can also see a layer of JB Weld I applied between the two skins after reassembling the skins. Eventually all this will be covered with a layer of composite material.
Sometimes You Can Be Too Trim
The rudder fairing was the first piece I tackled and (naturally) I took off a bit material more than needed. To avoid having the fiberglass crack at some point in the future I borrowed a tip from another builder and patched in a thin strip of 0.020 aluminum using a strip of bi-directional glass cloth and resin.
You can see that I only added the aluminum to the forward sections where the flange was too thin for my liking. Also, the tips of the cleco clamps are wrapped in packing tape to prevent them from becoming permanent fairing accessories.
I made a similar mistake when trimming one of the h-stab fairings, cutting it to close to the end, right through a rivet hole.
In this case, though, because I needed to build up the open side with fiberglass, I assumed (correctly for once!) that enough material would get laid down to provide a reasonable anchor point.
Cutting in Three Dimensions
One of the challenges of trimming these fairings in particular is getting the upper and lower curves to align with the elevator fairings. You want to follow the contour of the elevator tip and fairing, leaving just enough space to ensure the elevator can move freely but not leave so much clearance that it doesn’t look pleasing to the eye. As with my aspects of the build, the solution is to work slowly, making small adjustments as you repeatedly attach and remove the fairing using clecos.
You can see above that before you close out the aft portion of the h-stab fairing with fiberglass it protrudes a bit outside the edge of elevator fairing. My solution to this was to make the temporary foam rib (see below) a bit taller than the profile of the h-stab fairing, thus “tucking in” the outboard curve.
R V Serious?
See what I did there? Subtle Latin reference. I crack myself up sometimes!
One of the most mysterious aspects of constructing the fairings involves enclosing the open side of the elevator and vertical stabilizer fairings with fiberglass cloth. The diagram in the plans that tries to explain this is deceptively ambiguous.
The first stab is to fashion a temporary rib out of foam and shape it to the fairing profile. I ordered some PVC Divinycell foam from Aircraft Spruce for this even though the composite practice kit came with some blue foam insulation pieces. I figured I might need it for other projects at some point in the future. At this point he plans are not very explicit as to how to go about forming the rib. Here are a couple of things that I took away from the process:
You can approximate the profile of the fairing by firmly pressing it into the surface of the foam.
Given the curve of the elevator counterweight, the rib should be made somewhat concave, not straight as it is shown in the plans.
Unless you like digging out pieces of foam and epoxy from hardened fiberglass, consider wrapping the temporary rib in packing tape. Argh!
Rather than making the rib flush with the back of the fairing as shown, recess it 1/8″ or so to provide a “well” to fill with fairing compound/micro-balloons. Argh again!
Make sure to test fit the fairing and attach with clecos until you are happy with the profile. Yay!
As you can see from the last photo, the first layer of cloth detached from the fairings in a few places. I figured this was okay because most of the strength was going to come from the two layers applied inside the fairing. As long as I was happy with the shape (you can see this in one of the photos) I decided to move on. Also, because I did not apply packing tape there was some foam residue on the inside of the fairings but, again, since this was going to be saturated in resin in the next stage (and no one except me–and, well, you–would know about it) I felt it was okay.
The next two layers of fiberglass cloth went on pretty easily, though getting it to lay down in the tight inside curves was a but tedious. Incidentally, even though the composite kit came with calibrated pumps for the West epoxy system I found it easier to measure the resin and hardener by weight (5 to 1) since I was working with such small volumes. I used a small digital scale I had bought for the kitchen.
Super-sharp shop shears (alliteration!) and a Dremel tool with cutoff wheel made quick work of cleaning up the excess cloth and resin.
This Page Intentionally Left Blank
After reinforcing the fairings the next (and last) step in the plans is to rivet them on to the appropriate tailfeathers.
While the plans don’t dictate anything beyond this I have seen numerous builders apply composites to the joint between the two materials to make a more visually pleasing interface. In fact, the junction between the two components did look pretty amateurish. I contemplated leaving them as-is to reinforce to the FAA that this aircraft was, in fact, built by a total noob but, in the end decided to attempt to replicate my esteemed peers’ work.
In retrospect, I have to question that decision for the sake of my sanity. What became apparent quite quickly is something I’m sure builders of Long-Eze, Glasair and other composite aircraft are well acquaint with–the frustrating and fruitless hunt for smooth perfection. In a way, it is the definition on irony. I am building an aluminum aircraft, where subtle ripples in the skill and rivet lines are part and parcel, but somehow believed the tiny pieces of fiberglass at each tailfeather tip needed to exhibit the characteristics of the Hubble telescope’s main mirror. In case you are similarly afflicted I’ll briefly describe the high points here but, in truth, I am reluctant to relive this portion of the build.
I started by applying a layer of West Systems 410 filler to the individual parts in order to create a semi-smooth surface. I followed this up with a sanding and a layer of epoxy and micro-balloons. More sanding and a second layer of micro–followed by more sanding–yielded satisfactory pieces which I then riveted on to the main structures. I varied sandpaper grit from 80 to 220 and found these Durablock sanding blocks to be super useful.
Once riveted, I applied a layer of painter’s tape to protect the aluminum skin and repeated the 410-sand-micro-sand process to file and feature the gaps between the fiberglass and aluminum parts.
Once I had achieved reasonable good contours I hit the tips with a coat of SEM self-etching primer, which helped highly any ridges, valleys and pinholes. (It also offers a layer of protection to the layer of Alclad sanded off during the process.) Then it was back to spot filling with thinner and thinner coats of micro and more sanding.
In the end I was reasonably happy, if exhausted. Remember that gnarly gap between the rudder and rudder fairing? Viola!
There was also a pretty nasty gap where the v-stab met the fairing that I was able to disguise.
So after trying unsuccessfully to connect with my EAA Technical Counselor to come look at my elevator fiasco I decided to jump in the deep end and attempt a fix myself. After much thought and a few opinions from Van’s Air Force (including one that amounted to, “just give it a big ol’ yank”) I was pretty convinced the fix I had in mind would work. Specifically, my plan was:
Remove the elevator counterweights
Drill out all the rivets in the counterweight skins
Using fluting pliers to impart a corrective bend in the end ribs
Reattach the skins and counterweights
I started with the right elevator because it had the most interference, figuring if I could get that fixed the left one would be a piece of cake. (Yeah, right.) Step one, unbolt the counterweights. Step two, turn several dozen of the previous builder’s carefully driven rivets into metal confetti:
With the skin removed I had unfettered access to the end ribs and proceeded with bending them (to my will). I created a slightly exaggerated correction figuring that when reattaching the skin (using the same holes) would have a tendency to pull in back towards the h-stab. It did as expected after I clecoed the skin but did leave enough of a gap (3/32″) to resolve the problem.
From here all there was to do was to re-rivet the skins. This went pretty quickly thanks to the pneumatic squeezer I got from Cleveland Aircraft Tool. (I also got a t-shirt but this didn’t materially affect the process.)
Happy with my work on the right elevator I took the night off and tackled the left elevator the next morning. Oddly, even though I now understood the process it still took me about the same time to finish. Here’s a gratuitous time lapse of me drilling out the rivets:
In the end, I spent almost 10 hours correcting an issue that should have been done right in the first place. Happy days!
With much of the tail cone already done by the builder I purchased it from I only a have a few options for things to work on until the next kit arrives (in a few months 😒). In preparation for attaching the tail feathers I decided to work on the elevator trim servo. In particular I wanted to (a) complete a bench test to ensure it works and (b) sort out how I was going to connect the wiring to the eventual fuselage and instrument panel.
The Ray Allen servo setup is pretty straightforward. The kit comes with the servo, a three position switch, and a position indicator display. The wiring diagram is also straightforward–connect the colors as shown.
Since I have previously dabbled in microelectronics I have no shortage of stuff for connecting components like this. One breadboard, a power supply and some hookup wire later…let there be light (emitting diodes)!
I ran the servo through its complete range and after confirming the servo electronics I moved on to the hardware. The first step was to assemble the servo linkage and it was then I ran into my first real aircraft builder decision. The plans call for the three pieces of the linkage hardware to be rivetted together using two AN470AD4-7 rivets but for whatever reason the remaining hardware that came with the kit contained but a single rivet of this specification. Now, being new to this whole every-decision-you-make-could-be-life-or-death thing I sought out some advice from the “hive mind” of RV aircraft building: Van’s Air Force. One respondent suggested I just take a longer rivet and cut it down using a rivet cutter. While I admit it’s a great suggestion I don’t (yet) own a rivet cutter. Not wanted to delay the process by ordering a single rivet to be delivered via USPS during the Christmas crush I decided to use a AN470AD4-8 (just a mere 1/16″ longer than specified). I figured as long I managed to create a good shop head I would be fine. The Cleveland Aircraft Tools “Main Squeeze” rivet squeezer made easy work of that.
The next step was to deburr the trim bellcrank and assemble everything. That’s when I ran into conundrum #2. The bellcrank mounts were too close together and I could not fit all the called-for hardware in the gap between the two angle pieces. With the holes in the F-1095A servo bracket already drilled I decided to drill out the rivets in one of the brackets and fabricate a new one. Fortunately the kit came with some leftover 3/4×3/4 aluminum angle stock and this went pretty quick thanks to band saw, sander and grinder with Scotch-Brite wheel.
Because I had all the hardware already out I sorted out the positioning by first drilling the 1/4″ hole for the bellcrank hardware, connected the bellcrank, and then match-drilled the three mounting holes using the holes in the servo mount as a guide. In the end it probably shifted the remade mount outboard about 1/8″ but that was enough for the bellcrank to move freely. Four rivets later (I screwed up one and had to drill it out) and the bellcrank was in business.
At this point I couldn’t help but wire up the whole assembly and watch the bell, er, crank!
I am curious to see how this all goes together since the forward bellcrank attach point dips quite a bit below the bracket and seems like it would interfere but, hey, after all these years I assume someone would have fixed it if it were a problem.
The next step was to create an attach point for the wiring harness I planned to build. I wanted to be able to (somewhat) easily remove the servo assembly as needed and so there needed to be a way to disconnect the wiring running up front. The servo lead wires are pretty short and so you need to route them to a point quite close to the servo. Based on prior art from Mouser I decided to fashion a bracket that would hold a CPC (see below) from .020 aluminum sheet.
I started by fabricating a cardboard template that would provide enough space for the connector and a tab that will be used to rivet the harness mount to the servo mount. I also added flanges to provide stiffness to the part.
I transferred the cardboard dimensions to aluminum and drilled out holes for the connector using a step drill and the mounting holes (not quite getting them aligned straight but, heck, it’s buried in the back of the empennage after all). Then I cut, sanded and deburred the final piece (being careful to drill stress-relief holes at the bend points) and bent the flanges in a vise.
I then had to decide where on the servo bracket to mount it. It needed to be close to the servo but could not interfere with the mounting screws. I offset it enough to provide clearance and then test fit the entire assembly in the empennage.
With the hardware sorted and connected I moved to how I was going to mount and route the wiring. As I mentioned earlier, I got the ideal to use CPC (Circular Plastic Connectors) from Mouser, and so did some research on them. I liked the fact that they are pretty foolproof and easy to manipulate in tight spaces and so, after shopping around, I ordered a bunch of components from Arrow.com:
Now, all of those components are relatively inexpensive. What’s not inexpensive is the tool needed to crimp these particular connectors. At $200+ it seems like an extravagance at this stage but I see myself using these connectors a lot so I’m sure I’ll recoup my investment over time. (And, by the way, I also got the pin removal tool because I know I will screw something up at some point.) In addition to the specialty bits I also got some wire loom and silicone tape from Amazon and was ready to fabricate a wire hardness.
The first step was to cut the wire loom to length and thread the bare wires through. Of course I failed to recognize this as the first step and went ahead and attached the female sockets. This required carefully unrolling/re-rolling the loom around the wires. Argh…
Before I crimped the wires on the servo I tried practicing with some scrap wire, sacrificing a few connectors in the process. I found it a bit cumbersome to position the wire in the connector in the right way and also hold the two at the right spot in the tool. Also, the tool uses a ratcheting mechanism that doesn’t release until the connector is fully crimped so it’s nigh impossible to correct the alignment if you misalign something. Eventually I discovered that if I closed the tool until the first ratchet position I could maneuver a pin into the correct position and it would stay there. Then I could feed the wire into the open end and finish the crimp. In the end I got all five servo wires crimped without any screw-ups. Time to declare victory and go home!
Actually I forged ahead and finished the servo-side wiring by attaching the wire loom and silicone tape, inserting the pins, and attaching the shell clamp.
To finish out the wiring tasks I created a temporary wire harness to use during the install/adjustment process and tested everything on the bench. I only had one brief moment of panic when the servo didn’t work before realizing I’d inserted one of wires into the wrong row on the breadboard!
The final elevator trim task was to finish the E-616-PP trim cable cover plates, to which are rivetted a set of cable brackets. The previous builder had purchased a set of milled cable brackets from iflyrv10.com, but only after match drilling the holes using the stock Van’s brackets so these ended up as scrap. (Actually I ended up using them as #30 countersink guides.) Van’s brackets are nothing more than a nut welded to a piece of steel and if I had built the tail from scratch I would have upgraded as well.
For a reason never fully explained, he had ordered one replacement plate so one of my first orders placed to Van’s was for a second. Since, at that point, I had not transferred the project over to my name I’m sure the folks processing the order were perplexed why a “non-builder” was ordering this very specific part. A few days later I had my part and was ready to complete the step…until I realized I had somehow neglected to include a rivet puller with my tool order. Fortunately this is a non-aircraft specific tool so a trip to the local Ace Hardware store rectified the problem.
The assembly process went pretty quickly. It would have gone faster but it was the first time I got to use my dimpling table so I spent considerable time making sure I had the right dies, adjusting the table height and ensuring I was dimpling on the correct side of the skin.
One of the first things that happens when you start to build an aluminum aircraft is that your woodworking skills improve. This might seem counterintuitive but not only do you need several good-sized workbenches on which you will measure, drill and rivet, but some assembly steps require custom jigs or cradles be built. Furthermore, while I suppose you could assemble and airplane using nothing but hand tools, having a variety of power tools (in particular a band saw, drill press, sander and grinder) make the process go much, much faster. Therefore, one of the first steps in the aircraft construction process is to outfit your workshop.
Now I’ve been a bit of a workshop nerd for most of my life. I grew up on my grandparent’s farm and, like all good farmfolk know, you need a well appointed workshop if you expect to survive more than a few harvest seasons. My grandfather was the first influential person in my life when it comes to nurturing my DIY talents. Some of my earliest memories were following him around as he built (and repaired) all manner of farmhouse facilities. I had plenty of opportunity to observe. For instance, we got our fresh water from a spring near the Penobscot River, which was pumped several hundred yards up to to the house. It seemed like several times per year my grandfather needed to drive his tractor through the forest to the pumphouse and climb down into the pump fit to execute a repair. I never knew exactly what he was doing but was fascinated by the process. Likewise, his basement workshop was filled with amazing tools (including, as I recall, a dedicated saw blade sharpening machine). He built an apartment for my mother and sister in the farmhouse attic. As the kids say today, he had ‘mad skilz’.
The second major influence on my “craftiness” was my Uncle Bob, whom I got to spend time with during and after my stint in business school in Rochester, New York. Uncle Bob was a Kodak “lifer” who, along with his wife, Dallas (my mom’s older sister), had raised his family in a beautiful, turn of the century, arts and crafts home. He was planning his retirement during the time I lived nearby and I helped him rework part of his basement into a proper woodworkers shop (including chiseling a channel in the concrete floor for his table saw’s electrical connection). His passion was furniture construction but I learned a lot from him about general carpentry and, unlike during the time spent with my grandfather, I now owned a home and had reason to invest in some tools of my own.
Over the course of many years (and homes–and wives!) I slowly built both a modest workshop and modest carpentry (and other) skills. By the time we arrived in Colorado I was able to fabricate basic necessities like bookshelves, desk drawers, crown molding (through admittedly just barely) as well as tackle basic electrical and plumbing jobs. I was also comfortable with attempting basic plumbing and electrical tasks. My workshop consisted of few decent hand tools (gratefully bequeathed to me by my grandfather), some cheap power tools, and a basic workbench I built from plans found online. As the reality of an aircraft building project began to settle in I filled out the stable with few additional workshop tools that had been on my wish list and started work on additional workbenches for my impending assembly activities.
Like many builders my first task was to construct two Experimental Aircraft Association Chapter 1000 workbenches–or EAA 1000 for short. Their design, 2′ by 5′ with a shelf underneath, has proven imminently practical for a variety of homebuilt aircraft projects. By building two you have the flexibility of being able to push them together to work on large pieces (I’m looking at you, wings!) and, like other builders, I opted to create a lip on one side (all the better for clamping!) and fit them with casters to facilitate easy, single-person repositioning.
In addition to the standard workbenches I also fashioned a separate rolling work table for my power tools. This was a mashup of an old restaurant tabletop I bought at auction a few years ago (see, honey, not a hoarder!), some crappy drawers I had built for my wife when we were renters and kept around in the garage (see, honey, not a hoarder!) and some plywood (see, honey, that’s why we own a pickup truck!).
And, while not strictly a requirement for airplane building, I decided to (finally) have our garage floors finished, replacing a half-arsed job I started when we moved in. It is officially the second highest expense in the building process thus far but well worth it to create a space I’ll enjoy spending hours at a time in.
Now that I had a space worthy of highly technical and time consuming activities it was time to fill it with (more) tools. There is a small part of me that sometimes wonders if the real attraction of aircraft building is the opportunity to acquire more tools but I try take my mind off it by browsing the Grainger website.
While most well-appointed workshops do contain many tools that can be used in aircraft building it’s not to say they always should, especially when higher-precision and purpose built tools are available. I, like many homebuilders, chose to “jump start” the tool acquisition process by purchasing a kit tailored to RV construction. Realizing the popularity of Van’s designs, several companies specialize in selling kits with most of the tools that most people don’t already have. While all kits contain the same basic collection of implements there are differences in optional tools as well as a range of prices. After comparing the options from companies listed on Van’s website I decided to order a package from Cleveland Aircraft Tool. They are certainly not the least expensive option but–based on feedback on the online forums–have a reputation for great service and tool quality. They also allow for some customization of the kit. After a couple weeks I got a pre-Christmas gift from my new best pen pals, Mike and Annette.
Experienced builders will notice a couple things in the above photo. First, I went with a C-frame dimpler. I’ll leave the endless “C-frame vs. DRDT-2” debate to others. Suffice it to say it’s what I learned on (during that one class I took) and I’m building my airplane in an apartment so noise be damned! Plus, I find the rhythmic “whack-whack-WHACK” to be a very soothing, Zen-like experience. Second, you can see a hand squeezer in the photo. I was impressed with the design of Cleveland’s “Main Squeeze” so I got one…along with a pneumatic squeezer that’s on backorder. I selected a Sioux air drill because of the reputation and often hook it up just hear it go, “Whizzz! Whizz!”. I also purchased Cleveland’s lightweight air hose and manifold kit so I didn’t have to constant swap the airline between tools. I attached the manifold to one of the benches so a simply quick-connect to my compressor supplies all my air-powered needs.
Speaking of compressors, another important building decision, I upgraded from my tiny (and loud) portable compressor to a 26 gallon oil-less Kobalt model from Lowe’s. While it’s not as quiet as a two-stage, oil-lubricated model it is rated the quietest among comparable models. I would have liked a bit more capacity but, hey, if it’s good enough for Plane Lady then it’s good enough for me. I did end up ordering a few more items form other suppliers like Aircraft Spruce and Arrow but I’ll save discussions on those for a future post where they actually get used. Until then, time to build something!