Month: September 2022

Cowling

This was an extremely stressful thing to do but also very rewarding. I got my little Sling TSI’s cowling fitted up and cut to the correct length. I used the whole painters tape trick to determine where to cut. It worked great. I did have to sand a lot down to make things perfect but the painters tape idea was a great starting point. I made sure to measure precisely that there was the correct amount of clearance around the propeller both front to back and up and down.

I put the top and lower pieces on the ground, clamp them together and worked my way back with cleco’s. After I knew where the cleco’s would go I removed them, attached it to the plane, and put them back on.

This whole plane build is being done entirely by myself without a second set of hands to help me. Mounting the cowling is one area that the manual specifically says to use a second set of hands. So I just pulled out ye good ole painter’s tape and used it to temporarily hold things in place and that worked great. That really allowed me to position the cowling exactly where it needed to be.

Interior

I was trying to fit the interior side panels. But they were a little too tight which would cause some bowing in the panels themselves. So I had to remove a little bit from one of the panels I peeled back the leather and cut about a quarter inch off the fiberglass. I scored it with a razor blade and then bent it and it broke and peeled right off. Now everything fits fine.

Oil and coolant Radiators

This was the first easy thing that I have done in a while. Everything else has proven to be harder than anticipated.

I installed the foam after cleaning the mating surfaces. I mocked up the location of the latches and marked them. Drilled them. Riveted then from the inside outwards. And everything worked great. They are nice and snug. I then tested fitted them against the engine and they for perfectly.

On to the next thing.

Cowling fitting

Okay so embarrassingly this took all day long. I built this little jig and added just enough washers to come out precisely to my calculated 25 mm clearance that I will need for my propeller,,, more information on my propeller to come,,,. That is 25mm between the front of the flange to the back of the spinner. Calculated at 31mm , minus 6mm.

Rear passenger floor

So I was concerned that where the passengers put their feet on the rear floor wasn’t solid enough. As you can see in the picture, the row of rivets I am pointing at is supposed to have a small brace under that thin piece of aluminum that they call the floor. The brace is only about half an inch deep. I didn’t feel like it would support enough weight. Or more accurately jumping and yelling and screaming kids. So I made the brace run all the way down to the bottom. So the new thicker brace that goes between the floor and the outer skin/bottom of the plane is 65mm tall. And then at the back bottom of that skin I put a piece of foam to fill the gap.

For better or worse it is definitely stronger now.

Heated Regulated Pitot with aoa

I chose to connect my pitot heat controller to the inspection hatch, has many others have done. I considered for a long time other places inside to mount it but none of them seemed as good as the hatch itself.

I was concerned that the pitot itself would go straight in and bang the aileron pushrod. If it goes straight in it will rub against the push rod. A slight bend of the aluminum pitot pipes towards the rear is all that was required to avoid the aileron push rod.

You can also see in one of the pictures the special tool I created to help tighten and loosen the inspection hatches.

I’m quickly running out of things to do. Because there’s only so many more things I can do without having my propeller or parachute. I have a couple things I’m trying to figure out this week that will hopefully help solve that problem.

Avoinics with Midwest Panel Builders

Christmas came early. I went back and forth a lot about whether I should do the panel myself or have somebody else do it. Deciding factor was that I want the highest quality install I can get and no one else has more expertise at installing avoincs, in Slings specifically, than Midwest Panel Builders. I definitely have the skill set to muddle through it and I could have figured it out but it wouldn’t be to the same level of quality that they can do it. So this week they have been here all week doing the panel installation. Now that they have been here and are mostly done, I’m very glad I had them do it. The amount of OCD and particularity that they put into their wiring is just unparalleled.

A huge advantage to having them do it that hadnt previously considered is, because they were here for a week,,,being able to ask them endless questions and be annoying as humanly possible to them has been a great education that I would not have gotten otherwise. A lot of us kit builders more or less buildings silently in our garage by ourselves. Being able to talk to somebody else and have them look at what you’re actually doing for any length of time,,, the value of that cannot be overstated. Not to mention it was just a lot of fun.

I did make some doubling plates for the antennas and I wanted an alternate static air source so I made a mounting bracket for that. So that gave me something to do while they were doing the wiring.

I’m not completely happy with the location of the antennas. I would much rather prefer them to be on the center line of the plane. But with the parachute and main support going down the center that just is impossible. They ended up being to the side of the parachute.

As mentioned in a previous post, I am getting the dual g3x and gtn 650 with smart glide and g5 and co2 detector options.

Sling TSI front skin

Front skin on. This went pretty smoothly. I was nervous about permanently sealing it up but did it anyway. I used RTV under the skin to make it water tight. I outlined the whole area with painters tape to help with clean up from over squeezed rtv. Remember to attach the defrost ductwork before you rivet it down.

Thanks Jean !!

Trying to figure out what was causing my rudder cable to rub was a lot of work. About 3 days wasted. (I can count these hours towards the plane build right? Even if I am redoing things, or just staring at the plane itching my head? ) I’ll admit I couldn’t figure it out. So I took to the Sling Builders Facebook group to get ideas. A lot of people really stepped up to help out and give great ideas, thanks to Oliver and Midwest Sky sports. But it was an unexpected phone call from Jean that sent me down the right path. He suggested checking the sliding plates under the luggage floor where the springs connect. The suggestion was to disconnect the springs and then loosen the sliders. And then position the sliders where the stops on the cable naturally fall. So what this accomplished was that the cable going to the rudder on the opposite side that is being pulled, has very little pressure on it. So it may in fact be rubbing or touching but it has very little pressure therefore it won’t cut through/wear. He did also mention that if my rudder is correctly configured it should more or less auto center. At that point in time I couldn’t even imagine that ever happening because I was nowhere near that. I used the luggage weighing device and I measured how much force it was taking to turn my front wheel even while in the air…. Using the hole for the tow attachment,, it was taking 35 lb of force to turn my front wheel…. That is ridiculous…

So for the fifth time I dropped my front wheel and sanded down the bearings… That helped a lot… But still not enough… So I also remove the pedals and sanded down those bearings… I used to micrometer to make sure I didn’t take too much off. I sanded them down from 5.6 to 5.45mm. Then I haf to reattach the pedals and reattach the front wheel l. Now as if by some sort of magic my rudder auto centers, barely. Which to this novice is perfect. Now the front wheel while in the air takes 5lbs of pressure to turn.

The cable going to the rudder, where it comes out of the rear fuselage, in my opinion was still rubbing too much. So I made the whole a little wider and a little further back. Jean also said this would be fine. I’m going to make a special piece of plastic to go over this hole which will make it look exactly like a normal hole. It’ll be just like the plastic (polypropylene sheet 3mm thick Amazon) that comes from the factory except a little bit wider. Should be a fun project for my Rotozip. To make the hole in the fuselage a little bit bigger, I was extremely nervous. But luckily this tool called a biter just made it like cutting butter, I could do it accurately and easily it was incredible.

Jean thank you for calling me after hours, your time, and spending 30 minutes listening to me uneducatedly babble about my problem. Your suggestions were invaluable. Thank you, Thank you.

okay, for documentation sake, and helping to spread understanding, here is a picture of the rudder slide control ,,

rudder centered below,

rudder full right below,

rudder full left,

Rudder cable rubbing

Why is this happening? I can’t have my rudder cable bending around this corner. It’s about a 20 degree bend right against the fuselage. It will rub right through. Yes I know the plastic guard isn’t on yet. I am just test fitting. And yes both cables are attached. And both are attached to the pedals and the pedals attached to the front wheel.