Built up J-3 cub build

[Mac82]

Here I go again,

Ok folks I'm bringing y'all a build log on ( you guessed it) a J-3 cub. I finished about 95% of the plans now transferred to the foam board in kit form



I'll be building this balsa style built up and reinforced with balsa or ply where needed

I've used about 2 1/3 sheets of foam board, I probably could have used a little less but I was trying to use up some scrap sections I had laying around.
I've only got a couple of the fuselage tail formers the landing gear and cowling then she'll be ready to cut out and assemble.
As you may noticed I've got the wing set up in ribs. This is going back to my earlier experiment with the built up wing with balsa foam and poster board seen here

http://forum.flitetest.com/showthread.php?21587-Foam-wood-paper-built-up-wing

But instead of using the poster board to cover the entire wing I'll only be using it on the leading and trailing edge. The wing tail and fuselage will be covered with monokote in cub yellow( again something I had for another project that didn't get used).

Thoughts, concerns, critiques always welcome.
I'll be updating you as the build progress.
Thanks for stopping by.

 

[Mac82]

I've managed to make a little progress today


The wing is starting to take on a familiar shape.
Most of the parts are just pressure fit for now, so I can make any final adjustments before I glue them in place.

 

[ClearSkiesCalmWinds]

Looking good. Subscribed.

 

[Mac82]

A little more reinforcement in between the ribs. Servo and aileron place ment this morning before I get to the house work

 

[AkimboGlueGuns]

How are you going to cover it? Regular monokote? It looks really cool as it is, and I might have to give that king of building a shot.

 

[Mac82]

I'm going to use poster board over the leading edge where it would normally be balsa sheeting then it'll be regular monokote.
In case your wondering yes I have done some testing on covering foam with the monokote it 'll work fine you just have to be mindful of the temperature and how long you keep the iron in a single spot.

 

[Mac82]

I just want to show some close ups as I progress
So here we go



Here is the mounts for the wing struts there eye pins from michaels for beads



The hinges



Max up deflection



Max down deflection

 

[Mac82]

Right wing half ready for glue


With a yard stick for scale.
It'll have a 41 in. Span

 

[Mac82]

No pics this time, just a quick update.
The right wing half went to gather a lot faster, after working out the spacing and errors from the first wing. I'll post up a couple pics after I get the poster board sheeting on then I'll cover the wings with the monokote.

 

[gabrielete]

Very cool and original use of the foamboard! I can't wait to see how it looks.

 

[Mac82]

Thanks gabrilete, I'll be keeping this build up to date as I go along. The wings are taking the longest, we'll cuz it's the most complex part of the build. That's why I started with them. The fuse should move along fairly quick but I will be taking my time to make sure everything is as perfect as I can make it.

 

[Mac82]

I wasn't feeling well yesterday day so nothing got done
But today was a better day
I got the wing sheeting done and almost ready for to the monokote witch I will do at the end of construction also I still need to work on the section where the wing will secure to the fuselage.

.

 

[Mac82]

More progress today


The fire wall and the motor mount cut out and shaped (final sanding to come)



Fuselage doubler and wing shelf reinforcement in place




And wing mounts and made and installed on wing

 

[Mac82]

Fire wall former and motor mount about ready to instal just need to cut down the rods after I get the right size, along with the landing gear mount on the right


The fuselage is starting to take shape

 

[Mac82]

Motor mounted about 2° down and about 2° right thrust



The tail feathers placed with the tail struts tacked in (they will be removed for covering) and the rear fuselage formers in place now it's time to set the servo placement. Now it's time to build the landing gear put in the belly plate and cowell. Then cover.




And a shot with the wings mounted, ya know for reasons

 

[gabrielete]

Congratulations again, your piper is looking fantastic. I'ts the first time I see the firewall with long screws to control angle. I think it's a great idea. How does it work??

 

[Mac82]

Thanks.
how they work? I guess by slowly twisting the bolts and setting them with the nuts. I also threaded the motor mount holes for 8/32 threaded rods so they are extremely secure. I'll just dab on a little paint to lock the nuts in place just to prevent any vibration from shaking them loose.

And about the bolts I figured it was the simplest way to mount the motor without adding a lot of weight or building time

 

[Mac82]

The wing window detail

 

[willsonman]

Looks good! Feel free to steal ideas from my SE5a build. More people NEED to discover how much more versatile FB is.

 

[Mac82]

Hey thanks I just checked out the build. I'm glad I'm not the only one to take this approach. It's the same way I plan to build my next two planes ( sopwith camel F1 & Newport 17)