Well I posted in General as an introduction but didn't even get a 'Forget It' comment. So I will try again.

I have need of a machine to cut Ply and MDF from 8X4 Sheets. I am thinking an Extrusion based build using a Kress spindle. 20mm Aluminium Plate for Gantry Sides, Rack and Pinion for the long (X?) axis and Lead Screws for the Y(?) and Z. Or possibly one Lead screw positioned centrally under the bed (prefered option)

One end open to facilitate loading would be necessary. Here comes the Interesting (but not original idea) I would like to build in a 4th Axis across the machine for spindle work. If it's not feasible then I will find a Lathe instead.

Suggestions for Min/Max Extrusion sizes and appropriate linear bearings eg Hewin or supported Rail (I am concerned there may be too much dust/debris for Hewin type Bearings) would be much appreciated.

Questions about motors etc can wait but I will again be looking for any help I can get.

A Workshop (read Shed) is being built to house the beast as we speak and will be ready by the time I have collected all the bits and pieces needed (I hope).