CoroPlanes Home

We design, build and sell model aeroplanes

We started building corex aeroplanes in December 2008. We have added XPS (extruded polystyrene) to our list of materials. Already we’ve built a few good looking planes ranging from the beautiful BeachCraft Staggerwing biplane to the modern F22 Raptor air-superiority fighter.

Depron is a bit expensive, so we use “isoboard” (XPS) or the next best thing that is Corex. Corex is relatively light, but not very rigid so unfortunately it warps easily – one good thing about using corex is that its impact resistance is very good; certainly better that polystyrene foam; the main draw backs of corex is that you cannot sand or file it to shape so you always get square “boxy” looking structures and wing spars are always required to stiffen the wings (we use carbon fiber tubes; Easton arrow shafts works very well ;-)). The best glue we found is “hotmelt”, but it has to be very hot to bind properly to the corex – we start working with glue temperature at 110°C (its too hot when the glue starts to boil inside the gun though ;-). Because the hotmelt glue is used as a filler-glue and sources heat to locally melt the corex it tends to add significant weight to the model – for this reason we eventually resolved to only tack parts together and not do continuous bonds thus we can save weight and the plane glides better in the end.

Services

1) If you have a defunct motor we have the solution. We rewind motors (brushed or brushless). Our friend reported excellent performance for the finished end product.

2) We build and sell RTF/ARF RC planes so, order yours today and specify your own colour scheme. Check out our Blog page to see what we fly.

3) If you bought an RC kit at a hobby shop and you need to set the radio up, we can do that for you.

Blog summary:

- African Black Eagle (Verreaux's Eagle or “Witkruisarend”) This project is having some difficulty – wing problems during flight tests. We're still working on it.

- The Swift has inherited the RC kit from the Arrow (temporarily retired) – it proved pretty aerobatic, but a little underpowered.

- The B52 is on hold due to wing problems – we'll also need to convert the wings from corex to isoboard (the corex wings were way too floppy and unsymmetrical).

- The EasyGlider's motor has been burnt out twice and rewound. Note: solder cannot stand the commutator heat for long – crimp fit works better.

Current & Past Projects

Beechcraft Staggerwing

This classic biplane initiated us into building planes with corex. The red-and-white version was our second try . This SA-flag version is of the same construction as the red-and white, but with a motor, fuel tank, receiver and servos fitted on a removable chassis – we figured this way we could stick this fully functional chassis into any model we built.

Theo's X-70

The X-70 has a half 3D half crossed fuselage with a wingspan of 61cm.And it glides well but in order to allow it to glide far you have to throw it hard because of its short wings. And it is very easy to balance. Very nicely finished in an American paint job. And it looks good!!

Lockheed Martin F22 Raptor

The F22 is similar in configuration to the F35, except that it has 2 jet engines (the real F22 also has thrust vectoring for pitch and roll). It was built as a solid fuselage with 50cm wingspan and looks really good. Our rendering of the F22 is stable and predictable even during a stall. 62cm wingspan.

Again the F22 built as a crossed-fuselage. Nicely finished with PVC film colour scheme.

Piper Cub

Built in the same way as the Staggerwing the Cub’s acrylic paint job also took some time. 75cm wingspan. The acrylic paint we used gave a matte finish and does not stick to the corex very well, but is cheap and easy – good for display.

Our own design: we call it the “Smitties RC ARROW”

This one came into being when we took parts from a broken RTF 2-channel RC plane and designed our own light and resilient yet well behaved flier. I figured Burt Rutan’s reasoning around the use of canards holds water.

Specs:
Weight: 240g
2x motors: 60g thrust each
Battery: 650mAh Li-Po, 2cell 7,4V
Wingspan: 61cm
Length: 62cm

Our own design the “Smitties Kiwiet”

Christo and Theo designed, built and did the colourscheme on this one. It was sold before it was finished – not bad for a day's work! Construction in 2mm corex and colour scheme with PVC film.

Its a very nice glider.

Specs:
Wingspan: 82cm

Our own design the “Smitties V-Plane”

Nico designed this one and did the colour scheme. Because it is short it is very difficult to balance, otherwise it glides well. Construction in 2mm corex and colour scheme PVC film.

Specs:

Wingspan: 66cm

Our own design the “Smitties Arrow II”

Theo's modification of the Arrow I. It is slightly smaller and glides very very well. Construction in 2mm corex.

Specs:

Wingspan: 56cm

Length: 56cm

A display model Microlight

Christo built this one for display – and it can glide backwards! Also with corex and light wood.

A display model Microlight (Cosmos Trike)

Theo built this microlight with corex and light wooden strips that his grandpa made for us. Glued together with hot melt, super glue (CA) with bicarbonate of soda would probably have worked better.