Amorphous M7/M6 Rebuild Project

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DavZeeMXT
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Re: Amorphous M7/M6 Rebuild Project

Post by DavZeeMXT »

A swing out right window…..nice. Will you be putting in the little vents too?
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Old Piper
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Re: Amorphous M7/M6 Rebuild Project

Post by Old Piper »

Hi Asa,

It’s coming along great!
Are you going to Rivnut the glass in or rivets? You may find rivets may put too much pressure and cause spider cracks around holes of glass, especially after a few flights. Rivnuts are also a lot easier for future change outs. A strip of padding under the glass to the frame wouldn’t hurt, for protection and air sealing. Have fun and the end is near!

Tom

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Re: Amorphous M7/M6 Rebuild Project

Post by asa »

DavZeeMXT wrote:
Sat Jan 21, 2023 7:57 pm
A swing out right window…..nice. Will you be putting in the little vents too?
The plane already had this window. If I had a large enough piece of acrylic to just go over the whole door, I probably would have removed the opening window haha. I rarely have passengers and when I do, they don't open the window. I won't be putting in the vents Maule does, at least not right away.

This is not going to happen (for now), but I'd really like a NACA scoop in the boot cowl with a 1" scat tube up to an eye-style vent mounted in the instrument panel to make it like a car vent. Have seen experimentals with the setup, and Maule has a drawing for a NACA scoop for cabin cooling air (5566F). It's mounted in the fiberglass engine cowl though, not the boot cowl. My M7 had an avionics vent like this (https://www.ebay.com/itm/403654033113) in the boot cowl. Same principle.
Old Piper wrote:
Sun Jan 22, 2023 3:53 am
Hi Asa,

It’s coming along great!
Are you going to Rivnut the glass in or rivets? You may find rivets may put too much pressure and cause spider cracks around holes of glass, especially after a few flights. Rivnuts are also a lot easier for future change outs. A strip of padding under the glass to the frame wouldn’t hurt, for protection and air sealing. Have fun and the end is near!

Tom
Thanks Tom! Was planning rivets simply because I hadn't thought about it past looking at what was on there and the drawing. I think I have a worse relationship with rivnuts than other people. I've had a bunch spin on me and I despise them. I like the idea of easily changing out though.

A change to Maule's window design that I think would be an improvement is to put an aluminum lip/skin around it to make the sealing surface the outside of the door instead of the inside face of the opening window. The acylic would be sandwiched between this lip/skin and the frame which would help distribute the loads better. Would eliminate the inside lip that the window normally butts up against and seals so you're not adding anything extra.

I think I'd love building an experimental where I can do every idea I have, and use all new materials. Or maybe I should go work for Maule? Haha.

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Re: Amorphous M7/M6 Rebuild Project

Post by asa »

A door a day keeps the anxiety away. All doors fitted and fabricated. Prep and paint next. I chose to make the door skins all one piece (an option on the Maule drawing) rather than multiple little strips. It uses more of an aluminum sheet and I imagine takes longer but I think it makes a better end result.

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Re: Amorphous M7/M6 Rebuild Project

Post by Kirk »

Looking at your choice on material for the side windows. At some point I will need to replace 1 or 2 of mine. I vaguely recall the choices are acrylic or Lexan? What are the differences or advantages between the 2?

Kirk

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Re: Amorphous M7/M6 Rebuild Project

Post by asa »

Kirk wrote:
Mon Jan 23, 2023 7:41 pm
Looking at your choice on material for the side windows. At some point I will need to replace 1 or 2 of mine. I vaguely recall the choices are acrylic or Lexan? What are the differences or advantages between the 2?

Kirk
"Plexiglass" = Acrylic. Hard, scratch resistant, very good chemical resistance. It's brittle, not really machinable in the traditional sense. Can be formed/bent/molded at higher temps. Care should be taken when cutting/drilling as it can crack easily.

"Lexan" = Polycarbonate. Super strong, some brands claim "unbreakable". Can be formed/machined in most ways. You can actually bend it in a sheet metal brake cold or cut it in just about any way you can think of including a shear. Scratches easier than acrylic and can be damaged by fuels/chemicals, although I think the fuel susceptibility is overstated for many airplane uses. Usually comes with a scratch resistant coating. Generally more expensive, especially Lexan brand.

Acrylic seems to be the accepted choice for windows and windshields in light airplanes although I think the opening window would be a good application for polycarb since it's directly riveted. There are light sports that make their windshield from a flat sheet of polycarb that is just cut and fastened in shape. I've heard people say a downside of polycarbonate is that you couldn't kick it out to escape a crashed airplane. Not sure that's true. In alaska we had a pacer on floats where both seaplane doors were simply a steel frame and a sheet of polycarbonate, no aluminum or fabric skin. Worked great, couldn't be done with acrylic.

Fun fact for nerds, acrylic is flammable in the presence of an oxidizer. Here's a rocket motor I made it grad school with acrylic (4" round piece with hole drilled through it) as the fuel. Oxidizer coming in from the left, combustion chamber is the hole through the acrylic, then nozzle on the right. It's called a hybrid rocket because the fuel is solid and the oxidizer is liquid/gas.

https://www.youtube.com/watch?v=AixgC9p2fv0

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Re: Amorphous M7/M6 Rebuild Project

Post by asa »

Another status update. Windshield installed for good. What a pain, but feels great to have it done.

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Doors are going through paint/assembly. Pilot door painted and assembled. Rest of them are in process. Did the center part black to "disappear" so it will sorta look like the big back window. We'll see if my imagination matches reality when it's all done. I think it'll be obvious whenever I remove the paper from the plexi.

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Overall how she sits currently. Looking angsty and disheveled, ready to break out of this garage.

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asa
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Re: Amorphous M7/M6 Rebuild Project

Post by asa »

Doors. Tinted acrylic doesn't look so dark in person. The pilot/copilot opening windows are clear. Would've been smart to leave the protective paper in place on rear door but I just couldn't stand it. Had to see what it looked like. Will refrain from removing it on fronts...

Also like two posts ago I said I wasn't going to install window vents. Ha! Installed.

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DavZeeMXT
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Re: Amorphous M7/M6 Rebuild Project

Post by DavZeeMXT »

I like the little vents. I think they work great. :)
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Re: Amorphous M7/M6 Rebuild Project

Post by asa »

DavZeeMXT wrote:
Sun Jan 29, 2023 1:19 pm
I like the little vents. I think they work great. :)
There are many styles, but I went with the rotating knob ones. I don't love the old Maule ones with the arm. Used a hole saw, cut from both sides to meet in the middle of the material followed by file/sand. Practiced on scrap first and preferred running the hole saw in reverse so it ground/melted through rather than digging in.

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Seats and seatbelts in, mainly verifying fitment and that I have all the right fasteners. Of course this will all come out for final inspection/annual which is now less than 1 month away. My IA is scheduled to start Feb 28th. Will I finish in time? Stay tuned to find out. You may also notice compass hanging on windshield and the **original** dome light re-installed. You can tell its legit Maule OEM because the brand name is Truck-Lite and it's a truck marker light readily available at NAPA. Also notice the different back angle of seats. I fixed the copilot one a few months ago. The pilot one could use a tweak. Everyone complains about Maule seating postion but I believe most of those complaint seats are bent or broken.

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Got the doors mostly sealed/weather-stripped. Could not refrain from removing protective coverings from acrylic. Satisfying. We all have our vices. The warnings say not to let it be exposed to sunlight with the covering on anyway and I am moving the plane to the airport in a few days...

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Re: Amorphous M7/M6 Rebuild Project

Post by drak130 »

Looks awesome. The amount of progress you have made in a short time is amazing. Good luck with the move.

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Re: Amorphous M7/M6 Rebuild Project

Post by asa »

drak130 wrote:
Wed Feb 01, 2023 6:17 pm
Looks awesome. The amount of progress you have made in a short time is amazing. Good luck with the move.
Thank you! "Short time" haha. Doesn't feel like it. Not sure if this was clear but I'm working full time on this at this point. I help my parents feed the horses (they board 120 retired horses at a couple different "free range" farms) for an hour or two in the morning then it's airplane time. It's a weird phase I'm in.

Have been doing little things on the cowling. Replaced baffle seals up front, degreased the inside, and did a small amount of sanding in prep for paint eventually. Lots more of that to do, was just seeing what it would be like. Will likely wait until after I get it flying unless I happen to have time. Added anti-chafe tape around boot cowl. The cheap cloth type wouldn't quite fit so I went with the teflon style. Not really sure about this. It may do nothing.

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Testing out some stripe schemes. Held on with masking tape for now. I know, I know, it's not normal, I get it. Red matches the wings, in real life its somewhere between the two shades seen in the pictures. Initial design had 1" spacing. Initial feedback said to spread them a bit which I agree with. Who knows what will end up happening or not happening with these. I'm a fan of AeroGraphics but I wasn't sure what I wanted so I found out what material they use (Scotch 220 Marking Vinyl) and ordered a 30" x 10yd roll from the distributor. Was significantly cheaper but you have to cut it yourself of course. What you see here is 52" so I will have lots left.

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Cleaned out the hangar I get to use for February. The previous tenant still has some stuff in it as seen. Hangar rent is so cheap here ($80!!!!) that people just hang onto them. I told him he could slowly move the rest of the stuff out if he would just let me move in instead of keeping it another month. Him and his late father build a Zenith in here years ago. They added the foam ceiling which is great. Wish I could keep this longer but in March it goes to the next person on the wait list. The airport manager is really doing me a favor by allowing me to slide in for a month between tenants to finish the project. Small towns are great in some ways.

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Re: Amorphous M7/M6 Rebuild Project

Post by whittakerw »

$80 for a hangar?! Man, I need to move...

It's looking great, excited to see it with some wings on soon.

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gdflys
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Re: Amorphous M7/M6 Rebuild Project

Post by gdflys »

Obviously he forgot the extra 0. $800/month here. :shock: :wink:
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Re: Amorphous M7/M6 Rebuild Project

Post by asa »

Yes the hangar rent is staggeringly cheap considering it includes electric and is about 1000ft from my house.

First time seeing the light of day in about a year. Got it all moved over to the hangar. Was also great seeing the plane in natural outdoor light today for the first time - it looks really good and I'm super happy with the tinted windows and the light grey tint on the windshield.

The holy trinity - old airplanes, old toyotas, old horses.

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