It was a surprise to me how the geometry of the propeller blades produced completely different patterns in the laminations on the front vs. the reverse. The pattern on the back of the blade reflects that fact that this side is essentially flat with an essentially equal angle through all the laminations. The pattern on the front reveals how the blade has an airfoil curved surface which is much flatter towards the tips and very steep (and thick) towards the hub.

This prop would have been designed to spin at about 1400 rpm. It's quite thick compared to the props we use on our RC models -- something on the order of a 18 inch prop with a pitch of 15-16.

I'll add also that carving the prop is not at all hard. Once you get your head around the ways things curve (e.g. which is the leading edge and which the trailing edge) the actual carving follows very natural lines. Whittling and sanding the wood seemed like the most natural and intuitive thing in the world. Actually the different colored laminations actually help in this regard since the pattern revealed during sanding can serve as a guide. The lines should curve smoothly. I didn't really have any idea what the reverse would look like but I noticed that once I had sanded the surface flat I got more or less equal bands.

Rough sanding was easily accomplished with an aluminum sanding bar -- followed by some 80 grit sandpaper wrapped around a 1" dowel section. I was also surprised by how easily the "hardwood" sands. The 80 grit paper cut right through it. In fact, I didn't use anything but sanding to shape the front of the blades. Besides, it was also fun to see sawdust in another color besides "balsa!"