Balsa plan for foam board

[fly boy3]

Hi all, have this idea for Winter build lol. Can you build a foam model from plans for balsa ?  Cheers FB3

[Ron Gray]

Yes you can, I did just that with the Hanky Planky plan that was in last Novembers RCM&E

 

 

[fly boy3]

Hi Ron, thanks for reply. Did you follow the plan as per cutting wing ribs , firewall, etc, or did you cut slabs of foam as per the flat wing KF designs ? Cheers

[Ron Gray]

I redrew parts of the plan to suit 6mm Depron construction, the wing was made from 2 sheets of Depron glued together then sanded. I later made a KFm wing which did away with the need for most of the sanding!

I’m currently looking for my next Depron build using 3mm and 6mm sheets and it could well be the Akromaster although I also have a few ideas around a design of my own!

[Eric Robson]

This is my Me110 built from foam board and depron, it is a scaled down Brian Taylor plan from 71" to 56". I changed the wing section to flat bottom, the fuselage is a foam board frame with 3mm depron skins. It has had over 150 flights and is still good, the  picture was taken last week. 

[leccyflyer]

I'll say it again, that's a bonny Bf110 Eric 🙂

 

[martin collins 1]

Built my Skystreak using the balsa plan as a starting point, changed the wing to flat bottom section and made the wing by cutting the bottom sheet from flat depron to the outline of the wing shape, added two full depth tapering foamboard spares (double thickness so 10mm) and cut the top skin from depron slightly oversize so it allowed for the curved aerofoil section. This was curved over a kitchen worksurface then glued on. Builds the wing very quickly, fuselage followed the plan more or less but with foamboard sides with the inner paper skin removed to lighten and aid the shaping, front formers were foamboard, rear ones were depron. Motor mount was ply and the front sides had very thin ply added to put some extra strength in the motor area.

[martin collins 1]

I have to say i really enjoy this form of building with the foam, i have so many rarely or not modeled planes on my to scratch build list! Trying to finish off a classic car build at the moment which i started 11 years ago 🙄, hopefully another 4 weeks will see it on the road and i can get back to my foam plane building.😁

[Steven Hurd]

Martin. 
 

I really like what you have done with your me 109, and indeed the skystreak. Could I ask how you formed the leading and trailing edges ? In my head at the moment all I can see is the foam either butted up together, or not? But by the look of your models they seem to feature a true aerofoil leading and trailing edge, and I’m left wondering how this accomplished. 
 

I have gone out and bought a few boards from hobby craft, and a few sheets of depron, and some B and Q polystyrene board. So I’m keen to get building, however I like to know how I’m going to tackle it before I get cutting and forming. 
 

Any chance you could give an example. 
 

I also like what Ron Gray  did to the hanky planky, a couple of months back I looked at that plan and thought it was a good platform for depron, went out and bought some, and next thing I know he’s knocked one up, flown it and got it modelled on a laser printer. He is a skilled and prolific builder. 
 

The Me 109 is a favourite of mine and your foam example is an excellent model.  
 

thanks 

 

Steve 

[Simon Chaddock]

People seem a bit wary of sanding a Depron skin to create a fine trailing edge.

Depron sands easily with new 60 grit sand paper if you do it on a flat surface.

Just be aware it creates a fine dust.

A 3mm all Depron wing.

The inside surface of both the top and bottom skins are taper sanded down to a 1mm thickness giving a 2 mm edge when they are glued together. 

As the glue area is quite substantial the edge is surprisingly 'ding' resistant.

I do the same thing with the 5 mm Dial XPS. It is just a bigger area to sand.😉

 

In this case the inside of the leading edges are just lightly sanded and glued together to allow a sanded radius leading edge.

If you smear the sanded leading edge surface with ordinary white wood glue it not only fills the foam cells to give a smooth surface when dry but adds considerable knock resistance.

It works for me.

[fly boy3]

WoW, some of these models are amazing. Would love to have a go at a sports model sometime.  Been building from plans for 30 years, never bought a kit. A plan, sheet balsa, some ply and away to go lol. Foam seems a different kettle of fish.  Iknowthat my models fly better when lighter, so foam maybe the way to go.  Cheers FB3

[Steven Hurd]

Simon, 

 

Thanks for the explanation and the pics that helps a lot. Sometime a pic is worth a thousand words, and these helped out with my visualisation of the build. 
 

cheers 

 

Steve