Cnc rails?

>>1240632
Linear guide rails are usually made of steel, so there you go

>>1240632
>Would stainless steel rails be more resistant to deflection than something along the lines of titanium?

I don't even think you can _get_ rails that are made of anything but some variant of chromium steel (effectively a type of stainless) without special ordering and paying out the ass. I've seen a few 3D printers that have carbon fiber tubes, but I can't imagine those are cheap, and they're not much more than a foot long, anyway.

There's no reason to use anything other than steel. You need them hardened to resist wear, and the stiffness of the rails themselves is almost irrelevant; they should be fully supported, and affixed to the structure of the machine itself every few inches.

Unless, of course, you're thinking of using unsupported rails. That, however, is flat-out not going to work for the kind of work volume you're looking at. You HAVE to use fully-supported rails for axes that long. The weight of the bearings themselves will throw them out a few thou without any load on them at all.

>>1240632
>CNC router

what are you routing that is that large, cabinet doors?

Like the other guy said, you need to support the rail the entire distance, which you could do with wood if your work does not require great precision.

>>1240789
That's actually one of the potential uses for this monstrosity lol.