I know I'm a bit late to add my 2p worth but I started out and more or less completely drew up an mdf machine before I started reading threads on this site and I think the wood bashing is very justified! Even on a tight budget steel Ali and 'proper' bearings make sense. I got change from £30 for 1500mm sbr20 rails from china - by the time you have bought Ali angles and skate bearings you have spent that... For a comparably rubbish set up. To me it's a no brainer!