Anybody else scratch building tonight?

[mastermalpass]

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:

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

 

[tomlogan1]

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.

 

[MaxTheFliteFreak]

You can do a Short Sunderland. It's a good looking plane and is an amphibian too.

 

[Brian B]

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.

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.

Zeke's offered a balsa kit, but he's out of business. Just look at that beauty!

 

[mastermalpass]

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! 😃

 

[dap35]

I have a spare 64mm EDF so I decided to scale up the FT-Bravo125% and convert it to EDF. I am also adding a working rudder.

 

[Brian B]

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.

 

[The Fopster]

Prototype 64mm depron EDF nearly ready for maiden. Build took a couple of days - V2 will be simpler and quicker again. Just need to finish it and see if it will actually fly!

 

[mastermalpass]

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]

Actually it was silver, done with Liquid Chrome paint pin. Soft lighting before.

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?

 

[F.K1999]

Maybe it’s not a scratch-build anymore, but my first 3D printed plane is finally ready for a drop test. I’ve used 3D printed parts before, but I never made a whole plane this way. And I also used to have some problems with designing complex aerodynamic shapes, but I recently found a good way to do it very fast and easy, using OpenVSP to create aerodynamic shape and CAD to add a structure. Seems like I got an extremely powerful tool to design and build more advanced projects.
I’m going to drop it from my trainer plane tomorrow, and if it glides back safely, I’ll add a rocket booster and launch it again.

 

[Inq]

@F.K1999,

Looks like a perfect candidate for a 3D printed hook on the nose and shoot it with a rubber band... a big one. How much does is weigh? About 8 inch wingspan???

 

[F.K1999]

@F.K1999,

Looks like a perfect candidate for a 3D printed hook on the nose and shoot it with a rubber band... a big one. How much does is weigh? About 8 inch wingspan???

Wingspan is about 9 inches. I don’t know its exact weight right now, but it seems a little bit heavy, especially compared with its foamboard prototype. But I hope it will fly nice with enough speed.

 

[Brian B]

Oh my, what am I getting myself into! I'm scared. Lots of planning to do, not building yet, but maybe a feasibility test-build of this 47" long torpedo soon.

 

[zenith.hjx]

I like my MinimumRC Star Voyager. since I had success with it, and difficulty following the little plane in the sky. I took a few minutes to resized it for a B-pack - 8" slow -fly prop power system. I cut it out a day or so ago. last night I got building.

With some glue time, and a men's NCAA Basketball Champion Game

Build-log here:
https://forum.flitetest.com/index.php?threads/minimumrc-star-voyager-build.68012/post-715803

How would you Paint/Color it?

No need to paint. Need some LEDs!

 

[dap35]

Finished my scaled up EDF Bravo - hoping to maiden tomorrow.

 

[L Edge]

Finished my scaled up EDF Bravo - hoping to maiden tomorrow.
View attachment 236499

Would be interesting to get the canards movable and it would add to the acrobatics.

 

[Brian B]

Would be interesting to get the canards movable and it would add to the acrobatics.

Here is my lesson from that experience. I made this J-20 for a friend, and on his insistence converted it from Elevons-only as intended, to Elevators and Ailerons, with elevator of course functioning the canard. My mistake was relying solely on the canard for pitch control, flew awful, no pitch authority. Didn't survive the maiden flight (on the test flight, he felt a need to bullet roll and go inverted before we working out the bugs, could not pull out of a dive). In retrospect, I know it would have worked great if used with an elevon MIX programmed with canard. Do that, thinking of the canards as pitch assist, rather than for primary pitch control. If you don't do that, at least add in "reflex" to the delta, with the neutral position of each aileron kicked up a little.
Once you get it working, you might try messing with the canard's phase in flight, for super slow flat flying (with Elevons converted to flaperons and canards pulling up).
Looks great, good luck.

 

[L Edge]

Here is my lesson from that experience. I made this J-20 for a friend, and on his insistence converted it from Elevons-only as intended, to Elevators and Ailerons, with elevator of course functioning the canard. My mistake was relying solely on the canard for pitch control, flew awful, no pitch authority. Didn't survive the maiden flight (on the test flight, he felt a need to bullet roll and go inverted before we working out the bugs, could not pull out of a dive). In retrospect, I know it would have worked great if used with an elevon MIX programmed with canard. Do that, thinking of the canards as pitch assist, rather than for primary pitch control. If you don't do that, at least add in "reflex" to the delta, with the neutral position of each aileron kicked up a little.
Once you get it working, you might try messing with the canard's phase in flight, for super slow flat flying (with Elevons converted to flaperons and canards pulling up).
Looks great, good luck.

View attachment 236523

I explored movable canards to really improve pitch and roll movement. Each canard gets a servo. What you do is setup 3 modes in your transmitter.
1) use elevons only
2) use elevons and canards set up with pitch only
3) use elevons and canards set up with pitch and roll

Using mixes and the mode switch, you start off flying mode 1 where you can kick out of using the canards so if trouble (one malfunctions or too much travel) and not crash. Then learn to fly with the additional pitch and see the difference in rotation. Then try it with roll plus pitch.

Here's a video of my design plane that was on "crack". It had elevons, thrust vectoring of motors(elevons and differential rudder) and working canards in pitch and roll. At high throttle in flight, this was a handful on where it would go. Stress came along after twentyish flights and destroyed it in flight.

 

[mastermalpass]

Actually it was silver, done with Liquid Chrome paint pin. Soft lighting before.
View attachment 236363
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?

For me, if and when such a challenge would be started, the scoring would primarily be on looks so any method would be allowed including 3D printing. With everything I've got going on though, I'd be happy if ai started it in 2024. I want to say October would be likely, but even that feels like a lot of pressure!