Steel for compound table?

[plasticad]

Hi all, I am building a small mill for home use (steel and aluminium) and I want to build a compound slide x-y (cant buy them for love of money in South Africa). I know traditionally they are made of cast iron with wear gibs, but as a friend has offered to machine it for me in his shiny cnc shop, I dont want to make him cut cast iron. What steel can I use - I dont want binding on the dovetails or "picking up" of the steel? Or any other ideas for a compound slide that does't involve big $$ ?

Many thanks,


Brian

[Geof]

It does not matter what steel you use it is not possible to run steel on steel without the very high risk of galling and jamming....although I suppose to be really precise if you had them hardened and ground it might work but that does not qualify as low cost. It is possible to use brass strips on one part so you have brass running on steel which is okay but then you can run into fairly rapid wear problems. Ductile cast iron is really the best solution because it can run against itself. Your best solution might be to promise to vacuum and scrub out your friends nice shiny machine after he has made the parts .