Quote Originally Posted by martin54 View Post
Jazz I understand what you are saying but from the little I have seen during researching building a machine Profile rails are very expensive & this would be more likely to put me off trying to be honest. If you are lucky enough to have money then I suppose you may not think of them as being expensive but on the limited amount of money I have available it's just not really possible & at my age I would probably be dead before I could save up enough lol.
If I do manage to build a machine I'm not actually sure just how much use it would get or what sort of accuracy I would require. Yes I can think of one or two things I would like to do with it & I realise that once it is done I might be able to come up with other ways to use it but I still can't see it ever getting more than a few hours a month run time.
he's not saying to use profile rails or else.. but there is an inbetween which are known as supported rails... now they are still quite a big cost of the total machine, but through doing my own research i personally have decided not to scrimp on rails or screws..

having said that if you check out trickyCNC's thread you can see what can be achieved by not using supported rails and by using mdf to build the frame, i feel this may suit you somewhat better.

the reason i asked this question about the round rails was to clear some things up... the outcome is that my planned 20mm round rails wold be better replaced by 16mm supported rails and have less room for error at roughly the same cost