Aluminium profile cnc build

[valdis034]

Hello everyone. I am here completely new, but thinking of building a cnc for a while. I had built small router from mdf sheet and drawer slides, so now i want to go for more accuracy.. :)

My aim is to build a machine with this working area: x1500 y1000 and z20 or 30. Not really sure about the Z. As I am now in a early designing stage all the advices are really apreciated. Main frame is going to be from 80/40 and 40/40 aluminium profiles. It will be used for wood cutting, plastic, mdf sheets and similar materials. Thinking about chinese 1605 ballscrews which I see are quite widely used, rails and blocks will be 15mm hiwin. Spindle is going to be water cooled 1.5kW or 2.2kW . Steppers nema 23.

My big question for now is from which width should be used two ballscrews on the longest axis instead of one ballscrew in the middle? I am worried about it can start to wiggle a bit, which off course will affect accuracy. All the sizes of ballscrews, rails steppers and spindle are still considered, it is not my final decision. I found on internet a cnc with the same structure as I am thinking to build, so now you have rough vision what I am speaking about :) Thank you very much!!