Thanks guys, okay slowly getting some clarity

Think im going to go for the planetcnc Mk3/ 9 axis controller with ethernet as I really want to run this from osx. Its first I've heard of reliability problems of usb - I didn't know it could be a problem. I guess if you have large job/ material and committing time to a part build the last thing you need is any corrupt data!

My design is quite similar similar to that of diycnc http://www.mycncuk.com/threads/11628...per-CNC-Router
however a fair bit smaller. I plan this to be a small desktop machine, same size as the EVO (why are there so few reviews or videos of that machine?) and come in under 50Kg ideally , 40kg is a push im sure.

I have access to a workshop and a welder friend however he's suggesting I go with T slot Ali to prototype, then weld a proper gantry from 25mm square steel section later

In terms of the main components, and given the size, I have a couple of questions


1) should I use hiwin 15mm rails for all guides, including X? Or is this overkill - maybe use round bar for the x axis?
2) what brand of ballscrew should I use? I read some reviews suggesting some brands have lots of backlash - are Chinese suppliers generally okay?
3) For the Lichuan drives linked above and for this size of machine are these going to need more than a 320W power supply? Im keen to keep this low profile and was considering this psu https://planet-cnc.com/product/powersupply-48v320w/ . Its quite expensive , alternatively this one is 25% of the cost https://www.ebay.co.uk/itm/320W-48V-...cAAOSwMgdXzn13

Sounds too cheap for such a supply, has to be junk right?
Im just not keen on placing orders with china that takes 6weeks to arrive unless I know they are good/ worth the time (which is money after all)

Made lots of projects but have to say options on cnc diy is confusing - lots of Chinese fake parts , not clear manufacturer origins, model number differences dm860/L etc. A lot to digest

Cheers Jonny