Hi Guys

I am trying to translate an American CNC plan by CNC Router Parts. It uses the 8020 Imperial extrusions. Is this stuff freely available over here? I have found this site which sells similar profiles (are they the same?). 1530 8020 is 1.5" x 3" which converts to about 38mm x 76mm. The nearest size on that site is 40x80mm. Should I round up and use this? In which case, to follow the plan, would it be best to 'make it up as I go' when working out the lengths of each piece (using the US plan as a guide)? Or should I redraw the whole model and take the measurements off that?

Any help at this stage would be great. I'm completely new to CNC and struggling to understand, which is why I've selected a plan instead of my own design.

Cheers