Steve, take a look at this: [ame="http://www.mycncuk.com/forums/showthread.php?t=786"]Link[/ame]


Look for post [ame="http://www.mycncuk.com/forums/showpost.php?p=4282&postcount=9"]#9[/ame] by HS93, i'v been asking belt related questions as well, you can use that to work out what size belts you need.

I'v not seen anyone use two leadscrews on the X Axis befor, its normally the Y Axis they do it on to stop "racking", do you really need two?
If you could submit some of your design for us to look at it may help with ideas.