Quote Originally Posted by Jonathan View Post
To save repeating myself, please refer to this thread:

http://www.mycncuk.com/forums/faqs-p...ted-rails.html

Bear in mind the rails I modelled there are substantially longer than what you will require, so as Jazz said so long as you stick to a large diameter (=>25mm) short rail you'll get away with it. However if you compare that to the price of say SBR16 supported rails from linearmotionbearings2008 on eBay the difference in price is not that great compared to the difference in performance.

acctually looking at the prices of 25mm unsupported vs 16mm supported it works our cheaper using rough prices from zapp...

so my question then would using 16mm supported be better/as good as 25mm unsupported for a 15" x15" machine?