Feb 22, 2023     Aileron Links and an Elevator Bushing - (1.5 hours) Category: Controls

No exciting pictures this time. I installed the short elevator link pushrods that go from the control stick to the transverse bar. Surprisingly easy!

I also installed the bushing that goes on the link between the long and short elevator pushrod, per Service Bulletin 0021.

  Jan 30, 2023     The control tube locks are in place - (4 hours)       Category: Controls

Sort of anti-climactic, after a few months of working on the control tubes, waiting for parts, drilling the stop bushings and riveting them, checking the overall system for smoothness, putting in the linkages and the autopilots, it was finally time to close it up. That went remarkable fast, though I did need to use the hand rivet puller because of the lack of space. When it was all done, it looked, well, just like it should.

  Jan 26, 2023     Autopilot servos! - (5 hours)       Category: Controls

I got an earl shipment of the GSA-28s autopilot servos from Midwest Panel Builders, so I decided to install them. Installing them was, as with all things in the controls area, something best done by someone with much smaller and more nimble fingers than mine. I admit to losing a washer somewhere between the bottom skin and the spar. I imagine it will be there forever.

Figuring out how to install them was easy, but getting my fingers into where the nuts and bolts went was tough. the pushrod was easy on the GSA-28, but it was once again a pain where it tied into (inside) the alerion bracket. I spent a good 3 hours (ok, honestly? It was a bad 3 hours) trying to get all the washers lined up and installed.

My plan for the next time I need to do this trick is to use some string first and thread everything together in place, then push a rod that is thinner than the bolt from the non-bolt side (call it the nut side, I guess?) to get everything mostly lined up, and then us the bolt to push everything back out to the nut side, pushing the rod out of the way, the string out of the way, and all my troubles out of the way. It sounds good, we'll see how it goes the next time I have some pushrods to install.

  Jan 18, 2023     Re-did the steering controls - (4 hours)       Category: Controls

The stop brackets for the rudder pedals needed a little more rework (thanks, Yeol, for grinding those down). SInce I had the control rods and everything else with the rudders off to get to the brackets, I figured it would be a good time to put the leather boots in place from the cockpit, I mean flight deck, into the engine compartment.

That was a lot harder than it should have been. The leather, like all the fiberglass, was not pre-punched with the hole locations. Not a problem, I just put an awl through them and we were good to go. But, because of the sides already up in the quickbuild kit where the steering control rods pass through, not only was it hard to get clearance (needed a manual rivet puller), but I had to form the aluminum boot backers (I'm sure they have a better name) under the sides. Not easy when there are Clecos holding the leather in place. But, by pulling some off one at a time and putting them through on the firewall side, I was able to get it held into place using the holes I had already put in the leather. For the record, I did try gluing the leather to the backer, but it didn't hold. {Note added later - with all my great planning, it turns out I installed the boots backwards. The leather should be inside the plane, not inside the engine compartment}

Once the boots and their backers were Cleco'd in place, I needed to rivet them. Most of the holes were relatively clear, but Clecos are smaller in diameter than the rivets and there were some holes that needed to be drilled out. I figure that's a rounder hole in the leather, too, so it was all good.

Once that was done, it was relatively straightforward to attach the control rods. Not easy, because getting eyebolts into the slots has been tough for every control rod, but at least there was nothing to figure out. It just took brute force and a little luck.

I noticed that the rudder pedals were bottoming out on each other rather than the stops and was trying to figure out what was going on. Then I remembered there are TWO pushrods for adjusting the way the front wheel points relative to how even the rudder pedals are. I had them both too long, so when I shortened them both the same amount, the orientation stayed the same and the stops were what stopped the pedals rather than the rudder pedal bar stopping the pedals.

  Dec 26, 2022     The ailerons - glad that's done!!!! - (20 hours)       Category: Controls

First of all, the time is an estimate. It felt like eternity, so I know it was at least 20 hours.

The first thing I got to do was UNdo all of the elevator stuff I did. I thought I would have enough clearance to work on the ailerons with the elevator parts there, but that was not to be. I am sure glad I fastened them with Clecos and not rivets!

Where to start? Well, I've learned my lessons on thru holes for screws. Never trust that they are right, especially when there are rivnuts behind them. So, I checked and sure enough, I had to drill out the M4 thru holes in the Front Controls Top Cover Skin. That is not riveted in, at least on my build and at least at this time, so it would not have been the end of the world if I didn't open them up yet, but I knew it would be a problem later if I didn't.

I riveted the main spar control bracket together and I ended up doing those with a hand riveter since i couldn't get the rivet gun in place. Then I put a few of the M4 screws to hold the bracket in place while I was working on the rest of the joystick.

I had to rivet the locking ring for the bushing in place. It said to use 4 of the 4mmx10mm rivets. I say that's crazy, because I can't reach that far around, so we compromised. I installed one rivet. I was able to do the locking rings closest to the tail of the plane with the joystick assembly off, and then I did the locking ring closest to the joystick once it was in place and the bracket holding the back was in place. I'll whine about installing that bracket in just a moment, but I wanted to be clear that I did clear out the aluminum chips prior to riveting and prior to putting the top cover skin in place.

Then it was back to putting the 4 M4 screws back into place for real, using washers and lock nuts and everything to make it official. I was a little concerned that the M4 screws seemed a little scrawny for holding the bracket in place, but don't worry, they are not! First thing to mention is that there is very little space for my hands in there. I didn't think they were that big, but I guess they are. I ended up doing what I did before on the brackets for the springs for the throttle cables. I taped the nut into the wrench and used that to hold it all together. It was still a challenge. One of the nuts got crossthreaded. Then the head of the screw got stripped, because that's what M4 buttonhead screw heads like to do. I didn't take pictures of the removal process, so I'll try to be descriptive. First I tried to hold the screw head with pliers and vicegrip lock pliers while turning the nut. Nothing. Then I tried to use an oscillating tool with a saw blade to cut through the screw, but it was meant for wood (I didn't have a hacksaw attachment) and the screw is stainless steel and the saw blade didn't have a chance. Then I used a big pair of pliers (18" handles) and tried to just rip the head off the top of the screw, and even after being attached with the saw, the screw held firm. I was eventually able to break the head off, which left a very "scuffed" surface for the screw to attach to. I sanded that smooth (no need for sharp edges), and *carefully* put another screw, washer, washer, and locknut on it. It worked fine, but that's 2 hours of my life I'll never get back.

Then came the hard part. I put the cross control rod for the ailerons in place. This required pushing an AN4 bolt from the difficult side into a bracket, then put in two washers, then the eyebolt from the rod, then two more washers, then the other side of the bracket, then a bushing, then a 5th washer, and then the nut. I lost a lot of blood in the this process. Every time I work with sheet metal for long periods of time working on a single screw or bolt, I end up getting cut up. This was no exception. I finally got wise and pried the bracket apart a little bit, since the bolt was going to squish it all back together. I didn't get wise enough to do that until I had spent about 4 hours on this part of the build, though. After a lot of cussing, it was all finally attached.

Next step was to make the joysticks parallel, at least for the ailerons. I did this with a simple a level, screwing the control rod in and out to get to the perfect length. Then I tightened the jam nuts on both sides to lock it in place. I don't know if it really needs jam nuts on both sides, especially with one being a locking nut, but I am sure that that length is now fixed until I saw otherwise!

I then Cleco'ed the Aileron Control Stops into place and wanted to make sure I had the same amount of travel to the left and right, since I had heard from two other builders that it was a problem. I didn't have an inclinometer, or so I thought. I remembered that my phone had one on it, and as long as it was accurate to the nearest degree, I should be OK. I knew it was precise to the nearest degree, but I didn't know about accurate. So, I first made sure the plane was level (I'd heard stories about getting some plane part perfectly balanced, but only on tilted ground!). Then I measured the the angle of the travel for the joystick in each direction. Since I couldn't vouch for accuracy, I did the next best thing and went for repeatability. I measured each stick on the left and the right a few different times and always came up with 18 to -18 degrees of swing. I guess I was the lucky one who didn't need to modify the control stops!

With that checked, the last thing to do was to install the control stops with rivets. The instructions say to rivet it down from the top of the plane, and I was about to do that and was talking with another builder. He reminded me that rivet heads should be outside the plane and rivet tails should NOT be outside the plane. Excellent reminder! The instructions were wrong, but I riveted up from the bottom and all was good.

That was a lot of work, a lot of frustration, and a little bit of bleeding (which I cleaned off), so it sure does feel good to have it done! Next step is the autopilot, then back to the flaps and elevator.

  Dec 22, 2022     Center Console Throttle Quadrant - looking good! - (2 hours)       Category: Controls

Yesterday, I got the center console top plate back from Midwest Panel Builders, who will powder coat and laser etch it for free when you get a panel from them. The console for the throttle quadrant looks GREAT so I was able to finish up that piece.

The fittings were hard to screw into place, so I am hoping that means they are pressure and leak resistant, not that I broke them by forcing them where they shouldn't go. The only real tough ones were on the parking brake valve. They went on OK on the piston.

The nuts and bolts were also a little bit of a challenge to put in since they were buried so deep in the handles, but I was lucky to have a socket that would fit them.

All the cotter pins are bent, the bolts are tightened and torque stripe is in place, and this is ready to go! Actually, I didn't put the Locktite on all the individual M4 screws because their heads tend to strip easily (to the point where I just went out and bought a lot more stainless steel M4 screws of different lengths), but if those screws somehow vibrate loose, I'll put some Loctite in then.

  Dec 03, 2022     Elevator and flap pushrods - (7 hours)       Category: Controls

Even though I SITLL don't have joystick assemblies, I decided it was time to get going on the pushrods. Now that the long elevator pushrod is in, it was time to put in the short pushrod and the flat control tube and motor.

First things first, I put all the eyebolts and jam nuts on the pushrods. I got normal but thin left hand threaded nuts, but the thin right hand thread (aka “normal thread”) nuts were nylon locknuts. They go on pretty easily when the nylon is the last part to go on, but when they are acting as jam nuts, I wanted the non-nylon part of the nut up against the pushrod, which meant that I had to thread the eye bolts into the nuts from the nylon side. This sounded hard to me, and it turned out to be harder than I expected. I ran the eye bolt through the nut the “correct way” a few times to thread the nylon a little bit, then put the nut into a vise to hold it, then pushed hard and turned the eyebolt into the nut the wrong way. That was about an hour or so of work to do the 6 pushrods.

Then I had to figure out how to get the long and short elevator pushrod “axel” (my description, don't blame Sling for that!) bushings into place. This was hard because the thick brackets were already riveted to the thin metal that holds the bushings. It took some bending (but not creasing!) of the thin metal, and I was eventually able to get the bushings in. Those should never come out!

Putting the rivnuts into the top clamps that go over the bushings was easy (thanks for small blessings) and I decided to just cleco them in place. I have this bad feeling that at some point, I will need to move them to put something else in. I can already see that I will need to use the hand riveter to get at most of the rivets, so I don't want to have to drill any out.

At first, the elevator tube was hard to move back and forth and the flap tube was VERY hard to move. I was thinking about shaving down the bushing and then I remembered that I used grease to slide the long elevator tube through a bushing, so I put some grease in and around these bushings, too. They are now incredibly smooth and easy to operate, and I didn't need to take anything apart. I will make a note to clean and re-grease the bushings during condition inspections.

Putting in the flap motor was easy enough, especially since I could rotate the flap tube easily. In order to test it out, I just needed to put 12V on the Red and Black wire (reversing polarity reverses direction, just like a DC motor which, I guess, it is). Thanks to Adam at Midwest Panel Builders for the “how to” on testing the motor.

The last thing I was told on these assemblies was that I needed to rivet the rings in place (see picture with blue arrow). It makes sense because I don't want the axels sliding back and forth, but I put this in the same category as the rest of the riveting - I don't *really* believe that it is ready to go yet, so I am going to hold off on putting in the rivet.

  Nov 22, 2022     Long elevator pushrod - (1 hour)       Category: Controls

Now that the pushrods are ready for use, it was time to put the long elevator one the tail and into place. Well, first I had to move the plane out of the garage so I could get enough room to put the pushrod in the back. I got some help from David and Rosie to move the plane out and chock the wheels.

I put some weight on the front (the tail is supported in the garage so I don't need it, but rolling the plane out, the support was gone), put the pushrod in, saw it get jammed in the central bushing on the rivets, so I pulled it out and used a steel file to knock down the tops of the rivets a little bit. I did another test run, saw I needed to file a little more off, and did that a few times until the pushrod went *almost* through the bushing. Then I used some grease and put it all over the inside of the bushing. I held the front of the plane while David pushed on the pushrod until it popped through. Success!! And, frankly, not that hard to do. The hard part was moving the plane, handling the long rod, and moving the plane back, so I was glad to get that done while David was here.

  Nov 22, 2022     Ay-ay-eyebolts, they're screwed - (2 hours)       Category: Controls

I was feeling pretty uninspired to work on the plane since I still don't have joystick assemblies. When I was down at Livermore airport for an EAA meeting, I went to see Yeol, another Sling builder, and his build. I am *so* glad I did! While I was there, I saw a bunch of other things I could work on without the joystick assemblies. There is a lot I could do with the rest of the control rods and ventilation system.

Acting on a tip from Yeol, I chose a couple of sacrificial right handed and left handed eyebolts for the pushrods and tried to screw them all the way in and out. It was not easy! I guess in the manufacturing process, either the alodine or the riveting, the threads in the pushrods got messed up. I ended up spending about 2 hours with some screwdrivers in the eyebolt for leverage and WD-40 on the threads to try to help "cut" through. I also discovered that putting a jam nut on the thread helped get the screw's thread back in somewhat reasonable shape. I put the nut all the way towards the "eye" part of the eyebolt, then unscrewed it over the damaged screw threads to undamage them.

OK, nothing exciting, but it was forward progress, and that is exciting in and of itself!

  Aug 31, 2022     Had some time to kill so I worked on the center console - (8 hours)       Category: Controls

I don't know if it should be the "center" console or the "centre" console but since I am feeling American today, I'll call it "center."

This was pretty simple on the surface of it. Not a lot to put together, everything was packaged together, there were moving parts with castle nuts and cotter pins, it was all good. But those rivnuts... I ended up stripping two of them, which in my case means that the screw got stuck in them. I ended up using a hacksaw on the front of the screw and bolt cutters on the backside to remove the screw from the rivnut so I could drill it out and start again. That's why this project, which should have been about 2 hours, took 8. But, it all got done.

I needed to adjust the amount of thread in the piston for the brake. For some reason, it wasn't obvious that I needed to cut off some thread. I think that's because it was not in the printed manual, but it was in the online manual.

Then I took it apart again to get the top panel free and I mailed it to Midwest Panel Builders so they could powdercoat it and laser etch the insignia and labeling on it.