When my ballscrews come I'll tell you lol ;)

I bought these
http://www.ebay.co.uk/itm/2624523999...%3AMEBIDX%3AIT

and need to mount it to this style mounting bracket
http://www.ebay.co.uk/itm/2525494066...%3AMEBIDX%3AIT

according to the drawings there is a 14mm difference between the centre of my nema 23 mount and the centre of the BK12/BF12 bearing blocks.

Luckily I found a piece of scrap tool aluminium that's been milled flat to 14mm from a commercial printer so I intend to cut it down to make "spacers" for the bearing blocks from solid tool aluminium which should align perfectly.

I might have enough spare pieces to make a few spacers if you're stuck send us a PM.