Estimated main spar rivet holes to be counter sunk: 14,564,239,187
Drill bits 3.3mm, 3.2mm 4.1mm Montville Hardware, Montville CT
Master Precision level Accusize Industrial tools (Always sounds good when “Industrial” is in the name)
Wera Torque Wrench KC Tool (lots of good Teutonic precision here)
Counter Sink Aircraft Spruce
Milwaukee M12 Rivet Gun Coastal Tool, West Hartford CT
8″ C-clamp Johnson Hardware, Groton CT
After the Make-Over
We never go to the spa thinking we will come out looking the same as when we go in. A visit to your Personal Appearance Specialist (PAS) is straight forward: you ensconce yourself in the Customer Hold Down Chair for a nice relaxing make over. After all the scraping, spackling and hosing down, you are set free. You look different and questionably more appealing to the eye. However, if your PAS (the term “hair stylist” isn’t techy enough for aviation) is not a dedicated professional, and even worse, has more than one name, you’re screwed. Look at this Frightful make-over where the PAS had a side job working for the Pakistani ISI:
Before (L) and after (R) switching to an PAS with more than one name (Not to mention has a side job working for the Pakistani ISI)
.
Either way, the subject always comes out unrecognizable from before. Just like our little darling Sling wing parts after their day(s) at the spa. Removing the protective plastic film with their name tags robbed them of their identities. The deburring scraped away their dashing sharp looks, and let’s not get into what the Alodining and puke green paint did to them. Its worth mentioning some Slingers wired a name tag to each part before punting them onto the makeover bus, but that was just a little old lady at the cash register tedious. So, we decided not to go that route. Instead, we went forensic, matching each part to the right rib using the Legos drawings in the instruction booklet.
It took us all of a 3 hour YouTube marathon on a Saturday afternoon to get them sorted out. Once that was done, it was Officially Meccano Time. We figured to commence the Meccaning with assembling the proliferation of rib parts into actual ribs. This would cut down on the risk of all the little itty-bitty parts strewing themselves all over the garage during a febrile search for a missing croquette set or hidden potato fork.
It was fairly straight forward, although we should thank God the Sling Wing Legos Booklet is mostly pictures. which not only helped us determine what parts were what, they helped with getting them properly aligned for clecoing. Once we got the right parts aligned, we clecoed and then riveted them together when riveting time came. It wasn’t that hard a process, even a macaque monkey lacking two fingers he gnawed off during his tenure in the lab could do it with one eye shut while stoned on peyote.
We did have to pay particular attention to a few things, starting with the flap and aileron brackets. These had slight bends in them to align with the flaps and ailerons. Of course, the left wing had the brackets bent in the opposite direction from the right, so figuring which wing each bracket was supposed go on had to be figured out. We double and triple checked, just to make sure the bracket was bent so it pointed away from the rib, and by extension, the fuselage. (The left wing brackets are bent to the left, right wing brackets are bent to the right). The monkey might need both eyes open for this one.
this Right-wing flap bracket is bent to the right.
Main spar rivet holes to be counter sunk: 7,232,120,112 (Estimated)
Once we got all the ribs assembled, we decided to start assembling the left wing first, because we felt like it. We got underway with mounting both spars in the jigs. With that, we had a couple of issues. We here at Connecticut Slingers have an extreme hyperphobia to screwing things up. It comes from a couple of things. First, we are new to airplane building, and while we do our best to do things the right way, we don’t exactly know what the right way is. We have a lot of unknown unknowns, as well as a lot of known unknowns, and more than a few of not even suspecting unknowns, or suspecting unknowing unknowns. (Donald Rumsfeld eat your heart out)
Truth be told, building the Sling can be counter intuitive. What might make sense could be exactly the wrong thing to do. For instance, drilling out the wing spar mounting bolt holes is a massive white after labor day no-no. We learned this by watching the last few moments of Evan Brunye’s wing video where he made one of his nuked 6 leaf clover rare errors. He knew it too when he used a drill bit to ream out the wing mounting bolt holes. He recommended doing a more legitimate reaming with a genuine hole reamer. We ordered one, while seeking a second opinion. We passed a note to Mssr. Jean D’Assonville. He was emphatic and fervent with a text message for us NOT to ream, giving us his phone number and insisting we call him, his feverish response punctuated by mistakenly using “team” Instead of “ream”. We elected not ream nor call him for bail money at 3 am on a Sunday night.
We set aside the main spar mounting issue aside for the moment. And went to work on the rear spar where we found yet another unsuspecting unknown. The rear spar comes in 5 pieces, a real long Rear Spar Channel – (P/N WG-CHL-003-L-F-1), and a short one, the Left Spar Channel Extension (P/N WG-CHL-004-R-F-0) that orms the tip end of the wing and is riveted to the end of the long one using a coupling piece the Rear Spar Lower Joining Angle (P/N WG-ANG-010-L-F-0). So far so good. the brain rash comes from the two other pieces at the other inboard end of the long one, the Rear Spar Doubler Plate (WG-PLT-002-R-F-0) and Rear Spar Tripler Plates (WG-PLT-003-R-F-0) all of which had these slight bends in them. Intuitively, the bends match, maybe we should lay them against one another so there would be no gap between them. But then, is that correct?
The other end of the spar was a lot easier. We aligned the spar tip with the jig using snug fitting rivets through the holes in the jig and the spar, and clamped the jig using vise grip welding clamps. Refreshingly simple. We eventually inserted the little bolts and locking nuts and tightened them down.
Setting the spars in the jigs first is different from what Evan Brunye shows. He riveted the ribs to the main spar first then riveted the rear spar to the ribs, finally mounting the whole shebang onto the jigs. We’re not judging here. We’re just different. Suffice it to say that we had no problem slipping the ribs in place with the spars mounted in the jigs first, then doing the cleco thing. Fortunately, we remembered to install the first 6 ribs on the inboard end first, so that we could install the flap torque tube. This was not without a bit of confusion over which one was which. The wizards of Tedder Field came up with a clever way of helping us builders line the ribs up. The downside is that they didn’t tell anyone. Evan Brunye talks about it in one of his vibrant documentaries and explains it on the wing he had already assembled. Since Our Directorate of Research has strangely not found it in the Sundance Film Festival submissions, We are including a link to it here.
We also have a photo of what we are talking about below. You can see the ends of the first 5 ribs. 4 of them have little notches which are in different spots, rib 1 doesn’t have any. Rib 2 has a notch between the bottom 2 rivet holes, rib 3 has the notch between the third and second hole from the bottom, well we could go on, but the photo does a better job than our complicated drivel ever would. Just stare at the ends of the ribs and you can see the notches on the end flanges. Once we figured out the order, we clecoed the ribs in place.
the notches circled in red. rib 2 has the notch near the bottom, rib 5 near the top. Why don’t they tell us this secret in the legos manual?
Once those first 6 ribs were clecoed, we inserted the flap torque tube (P/N CT-AFL-001-X-F-0) through them before placing rib 7. It was a minor miracle that we avoided the embarrassment of forgetting it. The rest of the ribs were straight forward, and it took us all of an hour to cleco in place, It really was that food stamps in the mail box easy. Hallelujah and Thankee Jesus.
Main spar rivet holes to be counter sunk: 3,153,365,112 (Estimated)
Then came the riveting this first ribs in place, and our first bit of confusion.
The snag was that these first six ribs were too close together for the riveter. Not only that, but the rivets were too short to pass through the spar and then the inch thick main spar. This cannot be. Rivets are supposed to go all the way through, and form a bulb on the end. They were not supposed to disappear inside the bowels of a wing spar, never to see the darkness of the wing insides. We mentioned this to Mssr d’Assonville, and he shrugged as we hopped into a Sling TSi for a frolic over French Valley. Turns out the rivets do indeed form a bulb, since the aluminum plates making up the root of the wing spar have a gap where the rib rivets are installed. on the first rib, two bolts are used to do that bit of holding. With this brilliant observation we could move on.
Connecticut slinger Staff Sling Assembler installing Rib 4 while one loafs, and another pays homage to a bust of The Lord Slingungus, our inspiring sage.
We unclecoed the first five ribs and moved them aside to yield some room for the rivet gun. Once rib six was riveted, we slid rib 5 into place and riveted. Not so bad. Then came 4, rivet, then 3, rivet the 2, rivet, then 1 rivet. like good little ribs.
The last thing to do before we installed the skins was to counter sink the holes in the main spar. Regarding this topic, our Director of Clever Ideas Bureau insisted we add our bit to the teetering pile of stuff about it. We tested the special Counter sinking tool mentioned By Brunye and others. We also got an assortment of countersinking bits which screw into the receptacle of the guide, to make sure we got the right one.
Once all our stuff came, we found a that a nice 3/8” thick piece of pure acrylic plastic was a good way to try it out and find the right depth. it drills easy, fast and is cheaper than metal, but has a smooth consistently hard surface to observe the placement of the rivet head. Some other plastic would work as well, provided it hasn’t spent the last 20 years floating in the Pacific. We drilled a 
few 3.3mm holes, which match the 3.2mm rivets using our drill press. This made it easy to test the nice countersink a hole, checked it by inserting a rivet, mandrel end first (We won’t say how long it took us to figure that one out) and repeated until the countersinking was the right depth.
We would like to say that telekinesis was used to pull the spring loaded parts of the guide apart, for the photo below, but we stuck a crappy dimple die (the one Evan Brunye Told us not to get) to hold the pieces apart to illustrate. the toothed ring on the right slides back against the knurled ring on the right. to change the depth, twist the part on the left. the knurled ring on the far right needs to be loosened to allow the piece to slide. its spring loaded so it must be held. once the part on the left is adjusted, the sliding part will engage it with the teeth and keep it from turning.
Then comes frustrating part. The idea is to get the counter sunk hole to be just deep enough for the rivet to sink just a little bit below the surface. First, we screwed the proper size bit into the end (the holes for the spar require the 1/8th 120⁰ bit) Then we screwed the knurled collar upwards away from the spring loaded toothed ring, and while holding the toothed ring back we twisted the bottom cagey thing a little bit, left to make the countersink deeper, right more shallow. then we let the spring loaded ring go to engage the teeth on the cagey thing to keep it from turning. then we tried countersinking a previously drilled hole in the plastic. we checked the hole depth using a rivet, and then used trial and error over the next few holes in the plastic to find the right setting in the guide.
Countersinking is fun. countersinking is fun. counter sinking is fun. OHMMMMMMM!
With that done, we were ready for hours of counter sinking fun. Thank goodness we don’t live in the early 20th century when sticks and strings were all the rage amongst hole drilling enthusiasts.
With the ribs in place, we could move on to the next milestone, the skin. The placement of the ribs jiggled and jaggled the spars a bit, which made it necessary to we level the jigs once more to give the wing the right bit of washout twist. We are supposed to make the two jigs level, and we rabidly wanted them really level. To do this, we used a really genuine precision level, the kind hospitals use. We are not sure if it makes a difference, But dammit, we paid a lot for the level and wanted our money’s worth.
Early 20th century hole counter sinking. we’ve come a long way.
The level we got is this heavy beast (Photo of Level) chiseled and ground out of some sort of heavy grade machine steel. Inside was the glass vial that had the bubble, which functions the same way as a normal level and the ball in a turn coordinator. It was amazing how vertical-hold-sensitive it is. Just a teeny winsy itty bitty mouse toe touch on one side of the jig would move the bubble. We used a few scraps of aluminum to lift the low side, and a Irwin Quick clamp to squeeze the high end down cutting into our SBB. A lot of nudging, shimming, and clamping down. eventually, we got the jigs nicely and precisely level.
Our deluxe precision level.
Main spar holes still needing counter sinking: 0 Yay!
We decided to do the bottom skin since it was relatively flat and it would make it easier to catch all the dropped things while installing the tubing, wire and other internal fripperies. With the frame upside down, and accurately leveled, it was ready for the skins. It was magical watching the first bit of tinfoil on Olympic steroids flop out across the vast expanse of spars and ribs, it was as if it was creating a new firmament that one day, would carry our fat butts all the way to Block Island for dinner. It was truly a milestone, and we marveled at the majesty of it. The joy was short lived.
We started in the middle of the wing, Clecoing the holes in the main and rear spars and rib 10, all at once, then moving to the ends clecoing the ribs as we went. The result of sunken spans of oil canning across the acreage of aluminum reminiscent of the logging roads of the great North Maine Woods. Yep, lots of oil canned potholes. We tried to flatten the skin through various means while redoing the clecoes, even placing the bust of The Lord Slingungus, our dear inspirational sage, right dead center of the wing, and then clecoing, but it still ended up oil canned. We gave up and riveted.
We shared some photographic evidence of the offending skin during a summit with Mssr. d’Assonville in an undisclosed location at the airport, located right beside Fausto’s Bail Bonds in French Valley, California. We will not describe his initial reaction when he saw the evidence, but he steeled himself, and politely said “it wasn’t too bad” through weighted breath, shying away as we clambered aboard a newly completed sling TSI for the afore mentioned frolic over French Valley.
Bust of the lord slingungus, making itself useful. mixed media, 2021
Wretched cursed oil canning. It looks Butt end hippo ugly ripples across a tranquil aluminum sea.
Slinging frolic around French Valley
Back in Connecticut, it took all of an hour to drill out all the rivets.
It was about this time we saw the Wing Skin episode of the action packed, gripping and informative Evan Burnye Sling TSI building series. He mentioned that the wing frame may rack slightly where the spars stay parallel but are positioned just a little bit out of alignment in a way that along with the ribs, form an imperceptible Z like pattern when viewed from above.
To correct this, we clecoed the spars first, starting in the middle, and working our way out, alternating the placement of rivets, one in the main spar, one in the rear. Eventually, we had the front and rear edges clecoed, then we started in with the ribs, their flexibility gaining rigidity with each new cleco.
A couple of hours and a gazillion clecoes later, we had a nice de-oilcanized skin, ready for a brand spankin’ new batch of rivets. This was when we cued the aviation videos on the YouTube and riveted away with earnest glee.
In short order, the bottom skin was on for good, making a nice catch-all for all the nuts, rivets, zip ties, cell phones and whatnot used while we accessorized and decorated the wing interior. we knew there was a reason Mike Blythe included a bottom skin in his brilliant design.
Next: The Gizzards