Hello again all you CNC-jedi!

Jazz, still have no computer at home, the frame question has to wait. But here is another!

Ive read that Ali extrusion isnt flat enough to mount rails to (but Ive seen many builders do so) What do you think about machining a flat steel strip maybe 30-40mm wide, 4-6mm think and mount this between the rails and extrusion? Just drill through and use a longer bolt for the rails? Or would I just get the same imperfektion in the steel when I thighten the bolts?

Has anyone use this chinese type of rails?http://m.aliexpress.com/item/32446258288.html

Autocorrect om a phone is a bitch when not using your own language ;)