Several weeks ago I wrote in this link
"The weight of heavy watches tends to rotate them from the flat of my wrist around to the bottom of my wrist. Round watches are more comfortable for me than my big square 46mm watches because the corner of the watch bottom (near 2 o'clock) pushes on my protruding wrist bone."
So I decided to try making a lightweight round case for my 46mm square Parnis which weighed 157 grams. I liked the looks of the simple, high-contrast dial. But rarely wore it because it was not comfortable.
The finished watch is the same diameter (46mm) and thickness (13mm), but its weight is 57 grams - exactly 100 grams lighter.
My original intent was to black anodize the aluminum. But I'll try living with the natural color for a while first.
Note that I've rotated the dial 30 degrees clockwise. It looks level when my hands are on my computer keyboard or steering wheel. Under these conditions it looks right to me. But when I'm not typing or driving, it looks a bit odd. Perhaps I'll get used to that. But if I get too used to it, my standard watches might start to look odd.
I chose a "lugless" case design. It was easy with this movement, which has a smaller diameter movement than the dial. The lugless design is also easier to lay out with a narrow strap. This one is only 20mm, which looks a bit too narrow on this 46mm case. I have some more 20mm straps on order, which may look better.
It was an enjoyable, though laborious project. The space is so tight that I first designed it in AutoCad, then machined it to +/- .002" tolerance.
And yes -- it is much more comfortable to wear than the original case.
Update: 4/20/11 I narrowed the ends of a few 22mm straps to fit this case. I like this size better than the 20mm strap first illustrated. I also like their textured leather. Three new pics follow:
Update 4/23/11 I added two more pics. 20mm black straps with yellow stitching. Cloth first, then leather - my current favorite strap for this watch.