thanks for your replies. To answer your questions;
I want to use the camera slider (distance of 1 - 2 m) for filming. Programming it als for stop motion/timelapsing would be fun, but is only optional. First I want to be able to slide my camera at a constant speed. I would love to be able to control the speed, using a knob. So I could set it at a very very slow speed too. Maximum speed should be something like 2 seconds over 1m. I'm using the canon 5d m2, which is about 800g. I guess I just want the slider to be very stable and solid.
My budget is ofcourse as low as possible, but I'm willing to spend something between 0 and 450 euros.
What kind of material (motor? slider? rail?) do you guys suggest? I found something that looks interesting on the Igus website. http://www.igus.com/wpck/default.aspx?PageNr=3582&CL=US-en
Any idea on the cost?
Again; thanks for the replies!