George - I remember having a look at the Sigma printer (I think it was) at the Bristol show. I always wander round looking for ideas for my own builds! This was the first printer I have seen in the flesh with profile rails for guides, which must put the price up a bit. I was demonstrating my old Prusa printer on my club stand. It's a grotty old machine that is showing its age (and it wasn't that great to start with) but it has the benefit for demos that you can see all the working bits. The mark 2 will be a compilation of the best bits of all the machines I can find, and might even now use profile rails...

I'm a great believer in that old motto of the academic - pinch one person's idea and it's plagiarism. Pinch lots of peoples' ideas and it's research