Templates arrived

A nice surprise was waiting for me when I came back home from a long day at work:

…I’m talking about the templates 🙂

Did I mention that these airfoils are quite large? Everything in CAD looks the same size. There’s no palpable difference between 1 mm and 10’000 mm. You simple scroll in and out until the image fits your screen. Once you see the pieces live, you realize how big everything truly is.

Anyway, I started to clean and glue the pieces together:


This will take a couple of days to finish. I’m eagerly waiting for the styrofoam to arrive and to heat that wire up…

Drawings of foam-cutting templates ready

Last week I draw the templates for the center section’s pattern. I need these to cut the foam pieces that make the pattern up. I had to split the large ribs into thread-millable pieces, as the largest one is 2840×500 mm (111×20 inches) and cannot be milled in one piece by my friend. He is hopefully going to mill everything in 4 mm popplar plywood soon. I also ordered enough styrofoam material (14 panels of 200 mm or 8 inches width), which should get here within the next days.

Here’s a screenshot of the templates. Each piece is shorter than 700 mm (27 inches):


It looks like a nice puzzle for a cold winter night. I’m really looking forward to start!

For those wondering what the center section is:


If you put the cabin on top, you’ll end up with the final center section.

First foam cutting experiments

The shell layout of the center section is a sandwitch of carbon and honeycomb aramid core. Hence, a mold is needed, and before that, I’ll have to make a good positive pattern. This is my project for the next winter days.

My idea is creating a pattern by hot-wire cutting rigid polystyrene foam (XPS) into shape, sanding, laminating some layers of glas fabric, surface filling and painting to get a high gloss surface.

Sounds good so far, however, I’ve never cut complex foam shapes with a hot-wire before and the pieces I’ll have to cut are almost 3 m  (10 feet) long. This is why I made my first test with the green Styrodur today:


Though I used some old poplar plywood leftovers as templates, the shapes turned out pretty well. I think I’ll go for this material. A friend has a small thread milling machine and he could easily mill the templates…