Project 5 build thread

[alexM]

Eric and Gary,
Just let me know when you're ready. I'll come over and give all my typical bad advice.

I cranked out another amateur video showing my efforts at getting my wing covered. I've since finished trimming the root and tip ends and getting those wrapped over the cap strips. Doing the upper surface should be easier than the the bottom (hopefully I don't eat those words).


But then I ran off to the better side of the mountains to check out the hangar building process.
PXL_20220402_170916982.jpg
After four years of haggling with Grant County, the Port of Ephrata, the airport manager, various building code discussions, moving imaginary lot lines, and of course dealing with builders and contractors it was finally time to get started. I wish everyone worked as fast as the builders do. On Monday a guy showed up to level the lot and dig the post holes. On Tuesday the materials were dropped off. Wednesday the vertical poles were in place. The picture above was taken on Saturday morning. At some point in the (hopefully not near) future I will inherit this hangar, along with whatever warbird we have at the time.
I think it is 56x44 with a 14' high opening. In theory it could house a King Air C90 or T-28. More likely it will house a T-6 and (part time) a radial engine Kitfox.

[Eric Page]

Thanks for the offer, Alex! I'll definitely take you up on it, assuming I ever start making progress again. Amazing how easy it is to get buried in other garbage and lose momentum. This week is annual sim training...

I'd like to talk to you about the hangar as well. I need to get one put up in the next year or two (preferably before the Kitfox is finished) but I know virtually nothing about the process or costs.

Incidentally, Ephrata is where my flying career started. I soloed there at a CAP flight encampment in July, 1988.

[Eric Page]

This just posted on YouTube...

[Geek]

Eric and Gary,
Just let me know when you're ready. I'll come over and give all my typical bad advice.

I cranked out another amateur video showing my efforts at getting my wing covered. I've since finished trimming the root and tip ends and getting those wrapped over the cap strips. Doing the upper surface should be easier than the the bottom (hopefully I don't eat those words).


But then I ran off to the better side of the mountains to check out the hangar building process.
PXL_20220402_170916982.jpg
After four years of haggling with Grant County, the Port of Ephrata, the airport manager, various building code discussions, moving imaginary lot lines, and of course dealing with builders and contractors it was finally time to get started. I wish everyone worked as fast as the builders do. On Monday a guy showed up to level the lot and dig the post holes. On Tuesday the materials were dropped off. Wednesday the vertical poles were in place. The picture above was taken on Saturday morning. At some point in the (hopefully not near) future I will inherit this hangar, along with whatever warbird we have at the time.
I think it is 56x44 with a 14' high opening. In theory it could house a King Air C90 or T-28. More likely it will house a T-6 and (part time) a radial engine Kitfox.

I like Eric, really appreciate the offer and I live on the better side of the mountain to boot !! I am down in Fallon working with the Navy so my progress on the Kitfox seems royally slow right now. I get home for a week and then I have to go to Jacksonville to help the daughter with some work on her house before she sells it and goes back out to sea. After that there is the Fly In at Kitfox. And after that - hell I have no idea but I'm sure it will be something. Will take a look at your video on the covering effort for sure and appreciate the time and effort you do to put those out. Envious of the hangar don't you know.

Gary

[alexM]

Even though the night time temperatures took another dip into the low 30s I'm trying to keep up the momentum on my covering job. I got out the pieces of Oratex I previously cut to length for my upper surfaces and used my trick to pencil mark everywhere the wing structure comes into contact with the fabric. Step 1 was to cut off the excess which will be used to cover my horizontal stabilizer.

This shows the piece intended for my right wing, turned inside out and placed on the left wing. With the leading edge taped where I want it, and the trailing edge clamped as shown, I located the only penetration in the fabric (the fuel filler neck), applied the Ray Charles method of feeling the edge and marking it with a pencil, then cut it out with a single edge razor blade.
PXL_20220405_011924424.jpg
Then I smoothed out any of the bagginess where the filler cap served as a tent pole and re-clamped the trailing edge. From there 'ole Ray and a pencil makes it a 5 minute job to located all the places of contact. Super precision is not required since you intentionally color outside the lines but just guessing I would say the lines are within 1/4" of real life (and well within the variation between the wings - and I know that because I built them).
I went ahead and marked the fabric for the other wing already, and had marked up the bottom fabric for my left wing a long time ago.
PXL_20220406_184051050.jpg
During my lunch break just now I talked my favorite woman into helping me put the fabric right side out, on the right wing. I had a line masked below the leading edge where I was going to apply adhesive. This part is a sanity check to make sure the line is where I want it. Even though I used my leading edge template to mark the lines on both wings it is not an exact science. If the fabric is short of the line you would have unsightly excess adhesive visible, and if it's short then you don't have enough adhesive on both surfaces.

I just did a quick spot check after placing the fabric and it seems I might need to move my tape about 1/8" (possibly not once I get it all smoothed out). Super easy task. I will probably need to move my dining room furniture again so I can paint the adhesive on the three remaining pieces of wing fabric in one day. Not the most fun job but it is for a good cause. My goal is to cover the top surface of the wing shown on Friday and then hammer out as much of the left wing as I can during the rest of the weekend.

[alexM]

I'm on the mend from tearing up a shoulder which messed up my covering schedule. This past weekend I was mobile enough to roll out the top fabric for my right wing, and both fabric pieces for my left wing to paint on the two thin coats of Oratex adhesive. When I was sure they were absolutely dry I rolled them back up and set them aside.

Today was warm enough that I was able to clean any dust off the wing, wipe the overlap area of the existing fabric with isopropyl alcohol and get two coats of adhesive on. About 4:30 I started attaching the top piece of fabric. I took a short break for dinner and got back to it so I could get all of the adhesive activated and thoroughly rubbed in place with heat before the temperature dropped back down to the low 40s.
PXL_20220428_045244068.jpg
It was probably around 4 hours from the time I started until I stopped and took the picture. I've still got to trim and wrap the fabric over the cap strips (easy) and trim the trailing edge. No unsightly wrinkles anywhere though I will admit I had a bubble on the leading edge that I wrestled with for a while. I took my time and got it to go away completely.

In other news I got the email that my series 7 elevator was ready for pickup. I was already headed to central Washington which made a day trip to Homedale, ID feasible, so that is what I did. As always, everyone at Kitfox is very friendly. I was back home in time for dinner.

I started on my wiring schematics to make good use of my bad shoulder. I've seen some of the artwork put out by some builders so I wanted to do better than I might otherwise have done. Learning a new software package didn't excite me so I turned to Solidworks and went to work. I know it's far from ideal but I'm reasonably fluent in it and can draw anything I can imagine with it.

Since I have all my avionics I was able to measure everything and draw them up as 3D solid models. I worked quickly and drew each of them up as an individual part. The outside envelope is within 1/8". To save time I skipped including the hole patterns in the mounting tabs but I'll add those later. I'll be able to reuse the 3D models for any mounting brackets I need to draw up when I decide where they're all going.

Kitfox Electrical Component iso.jpg
I'm not having very good luck posting images where the text is legible but with the ability to zoom and pan it is very usable. Here's a few close ups which will probably also be unreadable.
COM PTT and Jacks.jpg
Stab Trim.jpg
TXP.jpg

[Eric Page]

Sorry to hear about your shoulder, Alex. Glad you're on the mend and hope there's no permanent damage.

Your wiring diagrams are remarkable. Never seen anything like that before. Well done.

[alexM]

Thanks Eric. Time and physical therapy are making every day better than the one before it.

On Friday evening I started covering my left wing. Taking what I learned on the right wing I did both lift strut cutouts and attached the metal doublers to the inside of the fabric (just like the Kitfox manual says). I had to fabricate the metal doubler for my forward jury strut attach point, drill the rivet holes, primer and bond/rivet it in place. Those two jobs and a very thorough vacuuming took me until Saturday afternoon to complete. I put the first coat of adhesive on the wing framework in the evening, and Sunday morning did the second coat. I let it dry and then started attaching the fabric in the early afternoon.

Not surprisingly, I'm getting faster and my quality is improving.
PXL_20220502_001304428.jpg
And where I had set the lofty goal of getting both wings covered this weekend, I discounted the amount of time I would spend installing the pitot/A0A probe. I spent the afternoon reading threads on this forum to see when/how others installed the tubing.

PXL_20220502_001033604.jpg
Now I'm switching hats and becoming a plumber. Seems like a fun distraction actually. I'm still considering stealing the idea of others by installing the OAT probe on the pitot platform, something I obviously have to decide before I go any further.

And while the main focus was on covering the left wing, I did revisit my right wing to trim off the excess, wrap the edges of the cap strips and plan my strategy for edge tapes.

[alexM]

Checking in half way through the weekend. There will be a Mother's Day brunch interrupting my build schedule but still plenty of time to check off some more boxes.

I completed the pitot/AoA installation after a lot of head scratching and trying different ideas out. Cutting the over length tubes of the Garmin GAP26 probes isn't something that can be undone so I approached it carefully. I had acquired the tools for cutting, bending and flaring the tubing months ago and practiced quite a bit on scrap. But like I said that was months ago and getting recurrent on the real tubes didn't seem like a great idea. So I practiced on some scrap again. Then when I cut the GAP26 tubes I practiced some more on the excess scraps.

1. The tubing cutter is the same low tech sloppy junk you would use around the house. It does the job but I found it important to clean the ends up with my 2" grinder with a Scotchbrite because if you don't you often get splits in your flare when it forms.
2. The tubing bender works fine. When I showed it before I was cautioned that there are better ones, and I'm sure there are. But I was able to make it work very smoothly and it was probably the best tool of the three for this job. Its only real limitation is only having one bend radius but I didn't need variety for this job.
3. The Rigid 37 degree flaring tool is pretty dang crude for this task. There are cheaper tools and this one was about $100 so I hoped it would do a decent job. There really is a lot of subjective techniques that need to be worked out by the user. For example when you clamp the tube in the tool it is easy to over tighten and scratch up the aluminum tube (especially the actual Garmin tube). It's generally accepted that you start with the cut tip of the tool flush with the top of the clamp bars but for everyone that recommends a starting point they'll tell you others have the tube above/below flush by 1/8" or so. Finally there's finding out how many turns you crank the knob to form a nice flare before it splits. And it is a very narrow window between what looks like too small and splitting. In my case 2.5 turns didn't flare enough, 3 turns would split it wide open. At 2.75 turns it would result in a tiny split in the otherwise nice looking flare about half the time. I settled on 2.625 turns which leaves a slightly undersized looking flare with no splits.

PXL_20220507_000813434.jpg
As I said I spent quite a bit of time figuring out how to pull this off. I wanted to be able to remove the pitot tube if absolutely necessary (say it gets full of bird guts or I have some kind of leak at those connections) and the design of the steel mast extension and the tube don't lend themselves to easy removal. The mast extension is installed from the inside of the wing, so it's there to stay.
My final version is shown above. Believe it or not there is just enough service loop there, and the bends in the tubes are staggered and at just enough of an angle that the fittings will pull through the mast extension. Then I got out bags of Nylon 66 wire clamps and screws and ran the tubing out to my wing tip along the upper stringer tube. I'm doubled up at both ends for strain relief, and every place the tubes came into contact with each other or a rib I wrapped it in silicone rescue tape (wrapping one tube first and then both together so the tubes don't actually touch).
I have mapped out a couple of locations for access holes but with Oratex I can put them in later, so for now there are none.

Oh. The steel mast extension came to me with no holes to attach the GAP26. I used a piece of drafting film, some tape and a sharpie pen to locate the holes on the outside of the tube but between the curved surface and my crappy spring loaded center punch which only marked into the powder coating, the brand new drill bit walked on every hole. Three of them were good enough that I could open them up just a bit but the fourth was not even on the right planet. I did the math on only having three of the AN526 632 screws and it would take about 2000 lbs to pull the probe out of the mast extension, so I'm going to just fill that fourth hole. Shh, don't tell anyone.

PXL_20220508_043317254.jpg
Which brings me to the money shot for yesterday. With the pitot probe installed I could cover the top surface of my left wing, so I did. I've still got to trim and wrap the cap strips but I need to ditch the rotisseries to open up access at the ends. After that is done I'll be attaching the aluminum strips for the wing tips and starting on edge tapes.

[jrevens]

…
1. The tubing cutter is the same low tech sloppy junk you would use around the house. It does the job but I found it important to clean the ends up with my 2" grinder with a Scotchbrite because if you don't you often get splits in your flare when it forms.
...

Alex - some random thoughts. I literally made thousands of flares during my working life… copper, aluminum and stainless steel. Like you’ve observed, it’s critically important to clean up the cut end. You need to eliminate the sharp edges (deburring outside and inside edges of cut) followed by polishing with something like 340 or 400 grit aluminum oxide sand-cloth. Lubricate the cone of the flaring tool with light oil, then clean the flare afterwards. Flared connections are strictly a metal to metal seal. Never leave oil or any thread sealant on the flare mating surface. In general it’s fine to use a tiny amount of lube on the back face of the flare and/or threads before assembly. This can prevent the tubing from twisting when tightening the nut.