For your application (current and voltage) it's probably cheaper to buy one from this place:
I need to build a power supply 24V 6A (preferably) or 4.5A, I don't even know where to start, can anyone help ??
If I were in the U.S., I would agree but since I'm not and I live in a remote region, freight and dollar exchange it won't be any cheaper ! That's why I want to build one !
I agree with ViperTX, you'll still have to purchase the components and have them freighted in.
But here is a link that shows clearly what is needed to build your power supply.
If it won't let you in, you need to join the Yahoo Xylotex group and look under files. its called CNC PS.PDF
Thanks for the tip.... I guess it will work.... I'll probably put something to adjust Vout since 28V is too high for what I need.