Shiny Objects
Stuff we used:
Rivnut Drill Adapter: https://www.astrotools.com/product/rivet-nut-drill-adapter-kit
Chapman tool kit: Chapman tools, Rocky Hill CT
Buffing wheel: Holdridge Hardware Ledyard CT
We humans have a crazy and expensive fascination with things that are shiny. We love our glitzy diamonds, glittery outfits and of above all else, our shiny Slings. Just why we love our shiny stuff is unknown. Kaitrin Meert at Delft University suggested there is an evolutionary thing going on with our attraction to shiny objects. According to her research, we associate the razzle dazzle of Taylor Swift’s rhinestone guitar with sunlight glistening on water or something like that. This whole concept falls apart when one considers a glitzy gold thing can remind us of a certain glimmering golden fluid. Yet, we are still attracted to shiny gold things. Honestly, the real reason we like shiny things is that they are cool.
Regardless of what different shiny things are made of, all shiny things are shiny because of the way they reflect light. Instead of scattering light as a rough surface does, it reflects it at the same angle that the light hits it. The more light reflected at that angle the shinier it is. If we want a dope nice shiny object, we turn to metal.
Shiny metal things have been bedazzling people ever since there were shiny metal things. Early metallurgists the world over found that, if a flat piece of bronze was polished, it could be nice and shiny. The trick was to make the metal surface smooth enough. The smoother it was polished, the shinier it was. The shinier it was, the more reflective it was. With a real slick dope polish job, a person in antiquity could see his or her reflection in the smooth surface. The ancient Chinese thought that with that kind of a shine, the metal could store sunlight. It questionable how successful they were. Interestingly, today’s, solar power enthusiasts found a way to do that with their own set of shiny objects, none which involve much polished bronze. Nevertheless, over the coming millennia new uses for shiny objects were found. William Herschel, The 18th century equivalent of Brian May, used some sort of shiny metal object to find Uranus.
Herschel’s practical use of a smooth shiny object was followed by yet other applications. Smooth shiny objects are also slippery shiny objects, as you will notice on the cam shaft of a Rotax 916 or the shiny flush riveted fuselage of a sling TSi. Suffice it to say that the shinier something is, the smoother it is and faster it goes. This comes in handy for our Slings.
As we left things in our last episode, we had quite a time with parts that had misaligned holes. The spar carry through and the ribs for the tail were bad enough where we needed to get replacements and wait for longer than the bathroom line at the farewell Black Sabbath concert. Never the less, The folks in Tedder field and Torrance came through, and we are now moving on to the next bit, mating the center fuselage and tail, and a bunch of other stuff.
Putting together the fuselage is a bit more challenging than the wings. There are a lot of niggling little parts that have to be inserted and secured in tight corners. We saw this when we had to install the pitch servo mounts and had to use a a pair of wire crimpers to install the wretched M4 Nyloc nuts in that space that is about the width of a single ply sheet of toilet paper in a Motel 6 bathroom.
This time around, we had another tight spot when we decided not to install the rivnuts in the parts that form the center console and the front control cover skins. We should have installed them first. At the time we were not to excited about the need to enlarge the holes to accept the rivnuts. We hemmed and hawed about all that drilling until we had accumulated hours’ worth of irritating not fun with a side order of consternation installing all those rivnuts in hard to reach places.
Let’s use the space between the control cover skins (CF-SKN-22-X-C-2) and the Flap actuator support channels (CF-CHL-017-X-C-1) to chew over this job. The space was too tight to fit the drill and the Astro Rivet Nut Drill Adapter (ARNDA). It was even too tight to fit the drill and bit in position to drill the holes bigger. Fortunately, after half an hour’s search in a febrile tizzy we found our right-angle adapter right in the drawer we had for it. That made drilling out the holes for the with rivnuts the fun part.
Then came the part where we need to use the ARNDA in all its distended glory. We were stumped on how to position the SpaceX Starship sized ARNDA and its drill to drive the rivet into their holes. We looked at using the right-angle adapter to drive the installer, but even that was too big. fortunately, a bulletin was released by our Clever Solutions Development Bureau (Remember kiddies, it’s CSDB Let’s use our acronyms, this is aviation) The Bulletin described a solution that was diametrically clever to the stupidity of riveting the control skins in place first:
“You idiots:
The Chapman tool set comes with a thin profile ratchet that we could use to drive the ARNDA. no bulky drill required.
Warmest regards,
CSDB”
Wish we had that idea sooner. Installing the rivnuts was breezed after we figured that out. Its easier to show than explain. Checkout the youtube short below to see how we did it.
https://youtube.com/shorts/LU7YITrbGns
With all that rivnut trauma out of the way, we could have some more with installing the control sticks. They complement the pedals nicely and provide good visual balance to the modern art sculpture metastasizing in our Garage Sling Building Headquarters. The Legos book was cryptic as to how to go about installing them. On page 54, it shows the Autopilot Bracket (CF-BKT-002-X-C-0) and Auto Pilot Mountings (CF-BKT-013-X-C-1) mounted in their spots but showed nothing of the mounts for the controls. We saw the control assembly on page 81 all beautifully decked out with the Main Spar Control Bracket (CF-BKT-007-X-C-4) and the Control Mount Bracket 2 (CF-BKT-022-X-C-0) in the Legos book, but not with its final entangling with the main spar carry through. So naturally we thought it was supposed to be assembled with the brackets first then positioned in place. What a MENSA Level concept that was. We will spare you all the whining about the aggravation that caused when it came time to put the business end assembly through the main spar webbing.
We first installed the control assembly to try the movement of the joystick for the aileron control. It was a bit rough so some sort of smoothing things out was in order. We did some stuff with the scotchbrite pads, and that helped a little built. But then, The CSDB issued another bulletin.
Brainiacs:
“Shininess comes from within, try polishing the torque tubes.
Warmest regards
CSDB”
It was forehead slapping cryptic as it was plain and simple. Shiny things are smooth things. Smooth metal surfaces are shiny. If we made the shaft of the controls shiny, it would be smooth and slippery. Smooth and slippery is goooooood!!!
While the controls were in situ, We did some buffing with Dremel, which improved things a bit. but then we decided to give a buffing wheel on the bench grinder a try. We marked the general area where the bushings were on the torque tube, and extracted the assemblies from the main spar webbing. The buffing wheel made short work of making the torque tube smooth and shiny with a hint of razzle dazzle. once we had it ensconce once again in its permanent home, it became a proverbial beautiful Easter egg hidden in the bowels of our sling.
We tested the assembly again, and what a difference, it is so smooth. (I’m actually taking a quick break from writing this rant to go down and try it yet again!)
and then there were the locking bushings on the torque tube. The 4 Locking Bushings keeps the control torque tube from sliding forward and back as it rotates in the bushings. These needed to be riveted in place, how could we forget that? Once more there would be more consternation as we would have to extract the rear part of the assembly from the main spar carry through’s metallic maw.
The Legos book tells us the bushing has to be secured using four 4 x 10 rivets (HW-RIV-153-X-X-0) of course, exactly where they were supposed to go around the bushing wasn’t specified. We guessed we would put one in every corner of the collar, about every 90◦ around it.
The first step was to slide the locking bushing up against the torque bushing. Next we marked its position on the torque tube while it was positioned in the control brackets. After that was marked, we maneuvered the control assembly out of the control brackets and wrapped painters tape around the locking bushing, just once, trimming it to match the circumference. Next, we peeled it off, measured it, did the math, and made 3 evenly spaced marks on it. The bushings are about 9/16” wide so we put a line on the tape to mark the middle (9/32” from the edge) of the bushing, that crossed the 3 marks we made and we were ready to drill. We also measured diameter with a pair of calipers and then tried mathematics to determine the circumference. It’s surprising how well that worked, it was spot on with what we did with the tape. It’s one of the few times in life that paying attention in math class proved useful.
We slid the bushing back into place lining it up with the mark on the tube wrapped the tape back on the bushing, and We were ready to drill. We used the hole starter to make the divet for the drill bit on the crosses, and then did the drilling. The rivets came next, and we could put the assembly back into the control brackets, after negotiating the Main Spar Carry through web. Checkout the link below for how well the joystick moves. not enough O’s in SMOOOOOOOOOOTH to describe this one.
https://youtube.com/shorts/RP9Tu5NhTnc
Things were moving along well, With the parts in our SPDR growing fewer in number we know we are closer to having a fuselage complete. The next part is one of those that made us think we were making some real authentic progress, installing the side skins. We decided to do just the right skin for now, this would allow better access to the innards so we can install the heating and electricity stuff more easily. That said, its remarkable that there was very little to complain about. Except for a couple of things. Given our difficulty with the tail ribs (See Holes episode) we had concerns with whether we would have obnoxiously misaligned holes in the side skins (CF-SKN-001-X-6). With relief, we are pleased to report there were none.
The only snag we had was ensuring the side rail gussets and spacers were in the right position. We studied page 91 intensely to make sure that the spacers went between the side skin and the gussets. It would be nice if there was some sort of verbiage saying that, and maybe a cross-section showing the layers. Just sayin’.
A bigger issue comes with the modest amount of dimpling on the skins. Early versions of the Legos book, such as 7.7, indicate that we need to dimple the top row of holes from where the fire wall is to where the main spar rib is. Since we enjoy dimpling so much we went full bore on that one, you can see what we did in the above photo. This is where the Front Upper Composite Skin attaches, and in Version 7.9, it is not dimpled. Brother Arjen Visser posted on facebook that he did the same thing, and he was given a solution, so we will fret and clutch our pearls over that one later.
The dimpling runs down the line of holes on the front end of the skins, which connect to the next shiny object in the project, the fire wall (FFR-FWL-001-C-F-3). It is nice and shiny. Sadly, all its shininess did little to make it easy to align its holes (The ones in the mounting flanges) with the Cowling mount strip (FF-STP-101-C-F-1), the Fire wall spacer (FF-STP-002-X-F-1) AND the side skins (RF-SKN-004-C-C-1). Compounding the effort was this confusing picture on page 95 that shows how all that was arranged. The cowling mount strip goes inside the flanges, the spacer strip goes between the fire wall and the side skin. Got it.
Then came the part where we had to cleco these cats together. Daunting even now to think pushing all those clecoes through 4 uncooperative layers at the same time. It was a struggle to get the whole lot aligned for the clecoes, and it looked rather gnarly.
We found that building the firewall assembly in layers helped make it better. We first clecoed the Cowling Mount Strips to the firewall. Then we did the spacer strips, starting at the of the strip, opening the clecoes and slipping the strip over the cleco and closing it, moving on to the next. It should be noted that the spacers are not exactly straight, there is a curve to them, and just how they are oriented is not clear. this may be why others have been having trouble with them. Never theles, building this in layers cleocing them together one layer at a time reduced the intake of stress relieving beverages, especially when we added the side skin.
We are leaving the firewall only clecoed to the side skin for now, in all its shiny brilliance. we read that it is easier to install the Firewall channels and brackets to the side skins first, then install the firewall. since we are not yet installing the left side skin, we will leave it as is. For the time being, we are installing the heat, electricity, and air stuff, which is easier to do with one side skin off.