Anybody else scratch building tonight?

tomlogan1

Well-known member
Four motor foam board plane

I have built a bunch of foam board planes and have been very satisfied with single engine and two engine varieties. I would like to build a four engined plane out of foam board. I have a few criteria:

1 Must be electric (have 2 1806 and 2 2204 motors
2 Can't have a wingspan greater than 48 inches (1219 mm).

Wiring is not an issue I have that covered. I'm not concerned about being scale and my builds are certainly not beatiflul like some of the builds I've seen here. More concerned about flying than appearance.

I can 3d print any parts needed.

I would welcome any design suggestions. Right now just thinking of a four motor Tiny Trainer, but theres got to be a better idea out there.

Thanks.
 

mastermalpass

Elite member
Four motor foam board plane

I have built a bunch of foam board planes and have been very satisfied with single engine and two engine varieties. I would like to build a four engined plane out of foam board. I have a few criteria:

1 Must be electric (have 2 1806 and 2 2204 motors
2 Can't have a wingspan greater than 48 inches (1219 mm).

Wiring is not an issue I have that covered. I'm not concerned about being scale and my builds are certainly not beatiflul like some of the builds I've seen here. More concerned about flying than appearance.

I can 3d print any parts needed.

I would welcome any design suggestions. Right now just thinking of a four motor Tiny Trainer, but theres got to be a better idea out there.

Thanks.

There was a Bloody WWII collection uploaded a few years back. A wide range of planes built in the style of the Bloody Baron. I can see a B-17 and a Tupolev Tb-3 in the list. Dunno if the plans are still available.

But, if you want suggestions for your own design, I shall suggest the Kawanishi H8K:

236298

236299


The fuselage has some relatively flat sides to the fuselage, which should make it fairly easy to capture a realistic form.
 
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tomlogan1

Well-known member
There was a Bloody WWII collection uploaded a few years back. A wide range of planes built in the style of the Bloody Baron. I can see a B-17 and a Tupolev Tb-3 in the list. Dunno if the plans are still available.

But, if you want suggestions for your own design, I shall suggest the Kawaishi H8K:

View attachment 236298
View attachment 236299

The fuselage has some relatively flat sides to the fuselage, which should make it fairly easy to capture a realistic form.
Thanks for the link. Gonna see if I can scale a couple of these to accommodate the 2204s & 1806s I have.
 

Brian B

Elite member
Maybe a little tough, but I'll suggest the Republic Rainbow, the most gorgeous 4-engine prop plane, ever. No compromise streamlining, nacelles that were basically like four XP72 Super Thunderbolts with those incredible R-4360s, it STILL holds the record for the world's fastest 4 engine "piston" driven prop plane. Last gasp before the jet (and turboprop) age.
nacelle comparison.jpg

A real foamboard challenge!

I modelled up a 3D solid model to made 3D print, and you can have the files if you want to slice profiles from a CAD program. I'm considering making a balsa model someday... still building up my skills.
20230206_202107.jpg
20230206_202134.jpg

Zeke's offered a balsa kit, but he's out of business. Just look at that beauty!
xf-12.jpg
Photo.XF12_1.jpg
 

mastermalpass

Elite member
Maybe a little tough, but I'll suggest the Republic Rainbow, the most gorgeous 4-engine prop plane, ever. No compromise streamlining, nacelles that were basically like four XP72 Super Thunderbolts with those incredible R-4360s, it STILL holds the record for the world's fastest 4 engine "piston" driven prop plane. Last gasp before the jet (and turboprop) age.
View attachment 236344
A real foamboard challenge!

I modelled up a 3D solid model to made 3D print, and you can have the files if you want to slice profiles from a CAD program. I'm considering making a balsa model someday... still building up my skills.
View attachment 236346 View attachment 236348
Zeke's offered a balsa kit, but he's out of business. Just look at that beauty!
View attachment 236345 View attachment 236347

Ooh that's very nice. A challenge indeed, I mean, not only do you have to figure out to capture that beautiful oval in foamboard, you also have to figure out how to give it a chrome finish. I mean, you have to - look how perfect it looks! 😃
 

Brian B

Elite member
Ooh that's very nice. A challenge indeed, I mean, not only do you have to figure out to capture that beautiful oval in foamboard, you also have to figure out how to give it a chrome finish. I mean, you have to - look how perfect it looks! 😃
A challenge, yes. But I think doable. I was considering a DTFB version first before commiting to designing a balsa kit.
This here was my 2nd scratch-build, and I've learned about since then. Especially about strong spars... 5th flight was fatal. Shame since it flew SO well! But I managed curved-taper tube fuselage OK, which is the challenging part of the Rainbow.
Screenshot_20230317_224123_Gallery.jpg
 

mastermalpass

Elite member
A challenge, yes. But I think doable. I was considering a DTFB version first before commiting to designing a balsa kit.
This here was my 2nd scratch-build, and I've learned about since then. Especially about strong spars... 5th flight was fatal. Shame since it flew SO well! But I managed curved-taper tube fuselage OK, which is the challenging part of the Rainbow. View attachment 236352

You did do well with the shaping there. And the finish as well, all glossy, no wrinkles. Y'know what, I think the rainbow is so beautiful we should do a build challenge of it at some point. Your model looks so nice in Bronze. The real one looks great in silver... Do I take it too far and make one in Gold? 🤣 Either way, it'd be a great challenge where most of the points are focused on looks.
 

Brian B

Elite member
Actually it was silver, done with Liquid Chrome paint pin. Soft lighting before.
16792015884415138349337391454615.jpg

I'm up for a challenge. As long as deadline doesn't interfere with work. Or the new workshop I'm building. Several 3-view drawings out there to use. Almost everything is a revolved shape around an axis, except for the rear tip of the nacelles, which turns into vertical oval-sorta shape.
Would a 3D printed skin on a foam skeleton be cheating?