Re: Wandering First Build - Finally Going Again

[Ron Dickey]

You are moving right along

Looks good what will you pull this with?

Ron

[Prototear]

Thanks for the encouragement, Ron! I'll use either a Toyota Highlander or Subaru Outback.

[rowerwet]

your are most likely beyond that point but for anybody else reading your build, the old tried and true way to take care of the inside of steel tubes, boiled linseed oil. boil it to remove any moisture, then pour it into the steel tubes, roll the structure around to get all the tubes, then seal the in and out holes. Steel tube airframes have been built like this since they were used as the structure of dope and fabric airplanes. Even modern steel tube planes are treated the same way.
https://www.facebook.com/pages/Found-Ai ... 6305265959 some pictures of a customer airplane I work on, made last year, it has a steel tube frame.

[KCStudly]

Would love to see that link rower, but for some reason it flags a proxy error.

Edit: I was able to follow the link from my home 'puter and enjoyed reading about Found aircraft.

[Prototear]

Hi Rowerwet,
Thanks for the suggestion, but I'm too far along and have already treated my tubes with the rustproofing. I had read about the linseed oil but this approach with the spray can and hoses to thread inside them was pretty easy to do, particularly with a frame that weighs 300+ pounds. It was pretty easy to do with the hose being 24" long and just under 3/16" diameter with a tiny brass nozzle.

I liked your pictures and airplane services on your linked page, and that looks like a beautiful area. I grew up straight across the lake from there on the other side of Lake Huron then moved to Seattle after college to design airplanes at the other end of the size spectrum.

Maybe that link just happened to work for me since my wife was logged into Facebook on this computer so it thought I was her. Since I don't have a facebook account, it might not have let me in to see it, but I'm only speculating why KC may have had a problem seeing it.

[rowerwet]

sadly, right now found is shut down, the company is for sale if you have the urge to own your own airplane company. Really it is too bad, the customer plane I work on flies about 100 hours a month doing pipeline patrol work all over the northeast US and parts of Canada. After years of flying Cessna 206's his employer bought some of the Found Aircraft Expedition 350's. As good as the Cessna is, the Expedition has it beat in many ways, faster, able to carry more (important as the pilot has to carry an immersion suit (which he wears to fly across the ocean from Maine to Nova Scotia), a raft, survival gear, MRE's, snow shoes, heavy winter gear and boots, or during the summer, his mountain bike, as well as all his forms, maps, camera's and radio's) a bigger engine and a smoother ride. He loves the smoother ride as he spends about 6 hours a day flying. He just got his airplane last summer and it already has almost 500 hours on it.

[Prototear]

This weekend I made the detailed cuts on the floor panels and dry fit them before repainting the upper side of the frame. Even though it seems like I had painted it at least once before, I had to repaint it because of the frame mods I had done in December. I waited to repaint it until after I dry fit these panels since I knew I would scratch the painted surface as I placed, removed and recut the panels several times to get them close fitting.
You may notice that the inboard wheel walls are slightly warped but this will be covered by interior skin and a mattress eventually anyway.




Over the basement storage area, I'll use either leftover aluminum honeycomb panels or plywood, either one being 1/2", but I don't have to decide yet.

Meanwhile, my awaited Magna-Lok rivets arrived and I spent one by testing it on my scrap to confirm that it spreads correctly (unlike the others I had tried to use). It worked well, and is the one in the smaller aluminum washer. I should have spent one of the other specialty ones this way, but I was too cheap to think it would have been worth the expense. It looks similar to a regular pop rivet but the mandrel stays inside and snaps off flush with the head.

[Prototear]

After painting, I prepared the frame for the floor installation. I cleaned it with mineral spirits and used double sided butyl tape. Since the tape is in a 3" roll and I needed both 2" and 1" strips, I cut the tape into 1/3 and 2/3 strips while still on the roll. It is too sticky and messy to cut off the roll - you can get it off whatever it touches, but only in clumps.




I lined up the front panel and drilled some holes, then used wingnut clecos as pins to align it after removing the panel, peeling off the tape backing, and placing the panel down one last time. I used 3/4" aluminum angle along the perimeter as both a doubler to spread out the rivet load on the honeycomb and to offer a vertical surface to attach the bottom of the interior plywood skin.







I've wrapped the open edges of the aluminum honeycomb panel with 3" aluminum vent tape rather than seal it with caulk or silicone to save work, mess, and weight. I figure this is good enough since no edges will be exposed to the weather. This tape is made for temperature cycles but I've put some on my scrap piece and alternated putting it in the freezer and in front of a heater, with several cycles and no sign of damage or lifting off (just to get a little extra confidence for the engineer in me, knowing I'll never come close to how much the tape manufacturer had to do).

Along the basement, the aft edge of the upper floor panel has 1/2" angle pointing downward to serve as a doubler and as trim along the basement. The black angle iron behind that is for the eventual basement cover to rest at mid-span since that horizontal frame member holding the aluminum panel is not wide enough.

Although I got this amazing honeycomb material for free, it has lead to higher fastener costs and effort to do it well (maybe I was just being cautious because of not being able to replace the material if I mess it up). It is still worthwhile overall, being stiffer, lighter, and rotproof!

[Prototear]

When I get these floor panels attached, I'll get back to planning my electrical layout and door design. I am leaning toward making my own doors out of leftovers of this amazing honeycomb panel, with some additional insulation and a plywood skin on the inside.

[Prototear]

I've had some distractions but am back to work on the trailer. I've been buying some materials, planning the wiring, a better way to hang the spare tire, custom doors, and a slide-out for the cooler to come out the side of the galley.

I have some major items now including some aluminum wheels from Craigslist (from a 1997 Explorer), a PD 4045 power panel, Fantastic Fan, cooler, and sunroof. My door hinges should arrive tomorrow and my slider windows should arrive a few days later. The wheels came with center caps to cover the lug nuts and extension in the hub. The cutouts in the wheels even have a teardrop shape to them!


In planning my slide-out for the cooler, I described some of the idea in another thread viewtopic.php?f=21&t=58758 and some of it didn't work, but I found a way to make it work. The reason for this is to be able to access the cooler while underway (to add food, beer or ice) and not have the weight on the tongue or have to open the rear galley hatch because of a bike rack likely being in the way. I had previously cut out some excessive side frame members to make room for the slide-out. This is on the left rear corner and it should all fit underneath the countertop and have the countertop about 35-36" off the ground as in a normal kitchen.


I had a scheme in mind to use the shallow SuperStrut channel but it was too shallow to allow the wheels to clear so I switched to regular steel channel. I got a flux welder at HF at the tent sale so I manged to weld up my frame with 1" square steel and add mounting tabs to my channel rails. Here is the assembled slide retracted (not actually fastened down yet to check for fit) and extended. I have used 6 overhead door rollers but may need 2 more. I'll use push nuts on the back of the roller shafts to retain them. One extra loose roller is shown in the middle. I've got some trim and a liner to put in my makeshift track to take up the 0.15" play leave a smooth path as it goes overboard.




This came out to about $30 in parts rather than over $120 for a pair of heavy drawer slides (so long as I don't count the extra hours spent planning and building it). I'll include a second set of rails and small door on the other side of the trailer for symmetry and to use the cooler on either side.

[Prototear]

I finally started on my doors, and figured I'd start with the small cooler doors in case I make a mistake then I won't be putting the larger pieces of aluminum honeycomb in jeopardy yet. I first made a template 17" wide and 17.5" high. It is as big as I could make it and still fit under where the countertop will go.

I first made a template with OSB, then used the router around it to trim the actual door cleanly. The skin of the aluminum honeycomb panel cut cleanly, but the honeycomb has some weird shapes that will be covered with trim anyway, especially in the corners. The white Kevlar on one side has a very slight fuzz that can be cleaned off with a file (it looks a little bit like cardboard cut with a straightedge and a dull knife, so I guess that the carbide-tip router bit is "dull" when up against Kevlar).


I then put one in the planned space to check clearance. I have about 1/4" clearance below the 1" steel frame but if I need more I can cut a larger radius later on the corner, or even cut it more parallel to the frame. I also have an old weld on the horizontal steel frame below the door that will also get back about 3/16" vertically if I grind it off. I figure I may weld on a small angle to the vertical trailer frame ahead of the hinge for mounting screws so I can offset the hinge-line away from the edge of the door opening so that when opened the door won't interfere with the cooler rollout track. I got the T hinges from eTrailer.


Here is a view the template and one of the doors with the latches placed in them (the hinges are not fastened).


I hope to start the passenger doors tomorrow since these small ones went reasonably well!

[Prototear]

This evening I was able to finish the wood template for my main cabin doors and cut the door skins from the leftover aluminum honeycomb that I also used for the floor. My template broke Sunday when I wasn't careful enough handling it so I had to make another one before I could cut the actual door skins

I decided to make my doors first before the interior walls as I figured the doors would drive the detailed measurements of the wall cutouts, and I still had some uncertainty in the door details (and risk of a costly mistake). Making these door skins get me past the most risky part of fitting my doors I think, or at least I feel more at ease now

Here are the 2 doors, the good template, and the top piece of my first (broken) template. I used a straight trimming router bit to follow the template clamped underneath the slightly over-sized pre-cut pieces of aluminum. They are 27" w by 40" high, with cutouts for 14"x24" windows. The construction plan is to sandwich these skins and 0.2" birch plywood for the interior, with 1/2" foam inside the sandwich along with plywood strips around the door edge for a solid trim mounting surface with a total thickness of 1-1/4" (or a few hundredths less). I'll use 1" T-molding around the door frames using the approach described in the DIY door construction thread http://www.tnttt.com/viewtopic.php?f=21&t=54654



The aluminum sheets I had were "rejects" for aircraft use so they had SCRAP written on them with a big marker, so I picked areas with less to clean up while not wasting any of the overall sheets. These need some cleaning and polishing since there was no PVC film to protect it from scratches.


Here is the edge view - the edge will eventually be covered by the T-molding, but I may want to cover or fill with something first, perhaps epoxy. On the floor panels I just used aluminum tape but those edges are all protected inside the walls and aren't likely to be exposed like the door edge might.


I will probably wait on the final door construction until I have latches. I still need to pick out latches and am still deciding whether to use retro handles, recessed rectangular ones like I have for the smaller cooler/cargo doors, or something else. I'll use the same hinges I have for the small doors.

PS. By the way, the wheels in the background of the first picture are on Craigslist for sale. The white ones are the original wheels I got with the trailer frame with worn but useable tires, and the others are 2 of a set of 4 from a '97 Ford Explorer (I kept the best looking pair of rims and put on new tires, and the pair for sale has tires that are shot). They are 15" x 7" rims with a 5x4.5" bolt pattern.

[jseyfert3]

Looks a bit heavy (vs my foamie anyway) but very nice. I'll be following along on this build.

[Prototear]

It is really solid but fortunately the aluminum honeycomb weighs only about 2/3 of the same size plywood. In hindsight I went a little too far with the steel frame mods underneath. With the steel wall frame though I'll fill it with 1" closed foam with thin plywood on the inside and aluminum sheet on the outside so much of the weight is already installed (I hope) if I don't get carried away.

[Prototear]

I made some progress this weekend, finishing the floor and all the little pieces of doubler/trim and another 100 rivets!

After the Easter activities, I finally got to working with wood finally rather than metal on this project.
The woodworking seems to go much faster than the metalworking! I started by cutting some old plywood scraps for the open basement covers, then made cardboard templates of the contours of the top of the steel frame and transferred it to a sheet of 5mm birch plywood for the first interior wall skin. In this picture I had placed a leftover scrap from what I removed months ago from the wheel well to double-check my marks before cutting.


Since the original frame builder built the steel frames with a template, the left and right sides are extremely similar. After cutting and fine-tuning the wall skin for the left side, it almost fit the right side except for a slight protrusion on one of the front frame welds and about 1/8" variation around the sheet metal around the wheel well. Here's the skins placed to check fit.


In this picture of both sides, the pipe insulation was there for cranium protection since I was getting tired of bonking my head and I had to pull it back from the sides to get the skins in place. I'll keep them there as long as I can though.


Last night I fixed my bandsaw so I can start cutting curved plywood rails to put into the roof to both support the things that will be in the ceiling (fan, sunroof) and keep the roof skin from sagging.