Clark Y airfoil for model aircraft

This Clark Y airfoil was part of a test. I was unsure if it is indeed possible to cover a 3D printed part with iron-on foil like Oracover. Recommended temperatures for the iron are around 100°C for a first fixing of the foil to the underlying surface, 130°C for the second round of fixing and up to 150°C to shrink the foil and get all the wrinkles out for a perfectly smooth aerodynamic surface.

I had printed the part in PETG from DasFilament.de and was very positively surprised how little the part was affect by the iron. I could attach Ora light without any troubles. If you keep the iron on the same position for a longer time (say 10 seconds) with temperatures of 130°C and more, then the PETG warms up enough to be bendable with some force, but it will not melt and cause a mess, not even at 150°C. So in general the test was very successful. It is in fact well possible to use 3D printed parts to make foil covered RC airplanes. In my humble opinion, this is much more sensible than printing the whole plain and ending up with very fragile designs. But I agree of course that it is much more work my way and working with an iron to cover a naked plane is not everyone’s favourite.

When printed at 100% scale, the part is 100mm long, 3mm thick and is made for a wooden main spar of 8x3mm and a secondary spar of 4x4mm, which are easy to get in most home improvement shops.

I plan to build a complete RC aircraft based on this technology, probably with about 100cm of wing span, which will use an airfoil of roughly this size. But that may take a while. Of course I will publish the plane as soon as it flies.

Let me know when you use this, I’d be highly interested to learn about your results.