Well, I've been reading the Alternative Imaging thread for a little while now, and I finally decided to make myself a respectable mini35 for my XL2... complete with image flipper and XL mount on the adapter... the design is pretty much worked out (after going through an optics book). The one unknown as far as contruction goes is getting my hands on just the female-XL mount. Maybe a broken lens off ebay?

I have access to a milling machine, lathe, etc, so I intend to make a very nice adapter. There's an aluminum scrap place that has 1" and up thick blocks of the stuff, so good materials wont be an issue.

Anyway, none of this is the reason for this post. After sorting out details, I realized that it really makes sense to think about a rail support first (another thing that's overpriced to buy, as we know!). The big question is this: What are they usually made of? The ones I've seen seem to be from 3/4 to 1 inch in diameter... are they stainless steel? I was thinking either that or titanium, which is probably overkill. I've seen pictures of traingular ones made of... carbon fiber? Ok, so that's the question: stainless or other?

I'm picking up the aluminum stuff tomorrow, and might even have something to take pictures of at the end of the day.

I've seen them made of either aluminum or carbon fiber, and are usually rods of 15mm in diameter spaced 60mm apart. Someone correct me on this if I'm wrong?

Ben is always right.
Also, I would like to know the title of that book.

I have seen rods spaced in 100mm, but it might have been for 35mm motion picture cameras. I know it's a standard too.

Ok, thanks for the replies! I'm going with the 60mm spacing and alum rods but 15mm seems like a small rod to support a big 35mm lens... is there a larger standard?

Unfortunately, no pics yet... my reliable source of aluminum has disapointed me.

The book is "Optics and Optical Instruments" by B.K. Johnson from Dover publishing (part of "Dover Books on Physics").

Thanks, the book is now officially on my christmas list.