10' Ford Tri-Motor

localfiend

I like 3D printers...
Mentor
Sweet, I love the Tri-Motor. This gigantic one will be awesome.

My wife got me the Twin Power Pack C for Christmas. I will add another one to it and make it three. It won't be real fast, but should fly scale.

Should work just fine if you keep things light. My 100" PBY worked with two C packs, though it was unpainted. That's the only thing I'd be concerned about, the rest looks great as far as keeping things light goes.

Wonder if you could simulate the corrugated panels with some really light body filler and a comb of sorts.

What's your estimated AUW?
 

Aviator08

Flagstaff,AZ
Sweet, I love the Tri-Motor. This gigantic one will be awesome.



Should work just fine if you keep things light. My 100" PBY worked with two C packs, though it was unpainted. That's the only thing I'd be concerned about, the rest looks great as far as keeping things light goes.

Wonder if you could simulate the corrugated panels with some really light body filler and a comb of sorts.

What's your estimated AUW?

Maybe a floor adhesive trowel? I would think that would still add quite a bit of weight though.

I don't really have an estimated AUW. I'm trying to keep it as light as I can while making it strong enough. Do you remember what your 100" PBY weighed?

The Tri-Motor does have a high lift wing. Hoping that helps.
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Perhaps a paper crimper?

They're not particulalry wide, but you could get a silvery metallic paper, run strips through one of these and 3M-77 it to the side. Only hard part is balancing weight vs strength of the paper and finding that bond in the finish you prefer.
 

Swimjim

Member
One Time

Red Devil makes a spackling compound called One Time. It's very light. Home Depot carries it. Might be worth a shot for creating a corrugated look. Great project! I'll be watching the progress!

Jim
 

Joker 53150

Mmmmmmm, balsa.
Mentor
Body filler for automotive work is typically very heavy, so I'd recommend against it. You can simulate corrugated metal by using small strips of balsa or basswood, which is what I'm doing on a 1/4 scale L-19 over in the balsa forum. There is also a vacuum formed sheet of plastic designed to mimic the metal available from Park Flyer Plastics, although the sheet is only about 2' long and about 8" wide.
 

localfiend

I like 3D printers...
Mentor
Maybe a floor adhesive trowel? I would think that would still add quite a bit of weight though.

I don't really have an estimated AUW. I'm trying to keep it as light as I can while making it strong enough. Do you remember what your 100" PBY weighed?

The Tri-Motor does have a high lift wing. Hoping that helps.

I think the PBY was a bit under 5lbs. Weren't any scales available at FT though.

It took 7000mah worth of 3s batteries to balance though.

You can figure out your foam weights by multiplying your square inches of foam used by .19. That'l give you total grams of weight. If you drew stuff up in cad finding the area of the foam pieces should be easy.
 

Aviator08

Flagstaff,AZ
Perhaps a paper crimper?

They're not particulalry wide, but you could get a silvery metallic paper, run strips through one of these and 3M-77 it to the side. Only hard part is balancing weight vs strength of the paper and finding that bond in the finish you prefer.

That looks kind of cool. Not sure how it would bend around corners though.
 

Aviator08

Flagstaff,AZ
I think the PBY was a bit under 5lbs. Weren't any scales available at FT though.

It took 7000mah worth of 3s batteries to balance though.

I hope to use three 2200 3 cell batteries. One for each motor. Placement will depend on CG.
 
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Aviator08

Flagstaff,AZ
IMG_0119.JPG IMG_0120.JPG
 

willsonman

Builder Extraordinare
Mentor
Honestly, the wing leading edge will make any corrugations an issue. I would say try to make that bend work first and if it's a no-go then forget the whole thing.
 

Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
Honestly, the wing leading edge will make any corrugations an issue. I would say try to make that bend work first and if it's a no-go then forget the whole thing.

That, and the corrugations are so fine in comparison to the size for a trimotor that painting/skinning the shadows on becomes an option, even at this scale. Anamorphosis is a powerful tool for creating the illusion of finer details.

Quick look at a few pics, I count 53-ish corrugations from wing root to waterline -- TLAR on your fuse says ~8in high? so 6-7 ripples/in . . . There may be a commercial product (pre-corrugated paper or crimpers) with that fine of corrugation, but it'll be around the smallest sheet size available . . . skin prints start to become a really attractive option . . .
 

Jw547

New member
Looks great, Tim. I can't wait to see the maiden. I am curious to know how the motor/esc/battery configuration works for such a model. I have never built a multi motor aircraft before, so this is new to me.
 

CaptBill

New member
I agree with crafty Dan on this. Corrugated metal has about a 2" profile. What is the actual height of the side of the plane, 10-12' ? And your model? Then scale profile is.very small, perhaps to small to make it worth trying to physically produce.

As soft as foam is and as sensitive as our eyes are to distortion maybe just drawing lines, lines that slightly distort the foam/paper will produce the illusion of the corrugated metal.
 
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Aviator08

Flagstaff,AZ
Willsonman said:
Honestly, the wing leading edge will make any corrugations an issue. I would say try to make that bend work first and if it's a no-go then forget the whole thing.

That, and the corrugations are so fine in comparison to the size for a trimotor that painting/skinning the shadows on becomes an option, even at this scale. Anamorphosis is a powerful tool for creating the illusion of finer details.

Quick look at a few pics, I count 53-ish corrugations from wing root to waterline -- TLAR on your fuse says ~8in high? so 6-7 ripples/in . . . There may be a commercial product (pre-corrugated paper or crimpers) with that fine of corrugation, but it'll be around the smallest sheet size available . . . skin prints start to become a really attractive option . . .

CaptBill said:
I agree with craftsman on this. Corrugated metal has about a 2" profile. What is the actual height of the side of the plane, 10-12' ? And your model? Then scale profile is.very small, perhaps to small to make it worth trying to physically produce.

As soft as foam is and as sensitive as our eyes are to distortion maybe just drawing lines, lines that slightly distort the foam/paper will produce the illusion of the corrugated metal.

I am beginning to think illusion might be the best answer. Maybe an airbrush shadow would work? However, I plan on just painting this prototype to KISS.
 
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Craftydan

Hostage Taker of Quads
Staff member
Moderator
Mentor
I am beginning to think illusion might be the best answer. Maybe an airbrush shadow would work? However, I plan on just painting this prototype to KISS.

The big challenge to your artistic skill . . . people perceive parallel-ness and spacing between lines with amazing precision.

It certainly can be done by hand, but it will be a test of skill. Good luck :)
 

willsonman

Builder Extraordinare
Mentor
Might want to give Rasterize a note. He may be able to do some amazing artwork that you can print out and super77 on as a skin.
 

AkimboGlueGuns

Biplane Guy
Mentor
What are you going to do for the engines? Did you have a dummy in mind or are you just going to wing it?

If you find/design a dummy engine which could be 3D printed I could probably run them off for you.