F3A Competition Results
Current Project: Extra 230
Piper PA-18 (Roedel)
Glens 30% Cap
Step-Four Milling
Vacuum Technology
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About Me


My current project:

Scratch built Extra 230

I have chosen the Extra 230 as it is a little bit unusual, compared to all the 330s out there. The plan is to design the plane in CAD using an original 3-view drawing of the full scale plane. Some changes will be necessary (like incidence) but these should be kept to a minimum. The whole plane should be machined on my Step-Four. The plane will be built to quarter scale in the first version.


I have used CompuFoil 3D for the basic design of the wing. The initial idea for the wing design was taken from Glens Cap/Extra wing designs. However, pretty quickly that initial design concept changed completely as you will see. The first version of the wing looked like this:

The immediate problem is quite evident: the spar would not stay 100% straight.


After 3 more versions to improve the design, I have finally arrived at Wing Version 4, and I am starting to like the design now!

The main thing I have changed is that I have added carbon D-section rods underneath the spars. Also, lightening holes are now more refined, the main spars are now in balsa instead of spruce, and the ribs use building tabs.

Here are the ribs and the spar webs (ater a LOT of sweat on the PC!):

Note the alignment tabs - these aid in building the wing true tremendously!

Putting together the wing is easy:

Here you can also see the carbon spar. Everything is aligned first, the tack glued with thin cyano.

Here you can already see the aileron sheeting:

And finally finished!

F3A | F3A Competition Results | Current Project: Extra 230 | Piper PA-18 (Roedel) | Glens 30% Cap | Step-Four Milling | Vacuum Technology | Photo Gallery | Links: Manufacturers etc. | Miscellaneous... | About Me | Contact

This site was last updated 09/04/06