Update,

After some research the 10mm ballscrews look like a wise choice (thanks Jazz), Linear rails are still looking like they are out of budget. With my current spec i am floating around the £950 mark which is very near the top end of my budget.

If i can maintain (or reduce this slightly) i would be happy. I am considering a steel box section frame which should reduce the cost (but most likely be less accurate because of my questionable welding skills).

Turning my attention back to the electrical elements and taking you feedback into account jazz i'm looking at the following main elements.


Stepper:
2A (Series) 4A (Parallel) /
8 Wire / 1.8Nm Holding Torque / Double shaft
http://www.zappautomation.co.uk/elec...per-motor.html

Driver:
leadsine DM542
1~4.2A 20~50VDC
http://www.ebay.co.uk/itm/Leadshine-...sAAOSwgQ9VkquT

Power supply
http://www.aliexpress.com/item/600W-...8-830534792d55

It would be good to get some feedback on this combination. My understanding is the DM542 is a lesser version of the DM556 you suggested Jazz. Do i need the additional "buffer" of the DM556?

Also the power supply is rated to 12.5A is this suitable for running the steppers at peak with enough of a buffer.

I am still working on the hardware design and will post up some images soon.

thanks,