Hi Robert,

My very first machine used plywood for most of the construction. It worked in that it moved around according to the g-code it was being given, and it did cut thin wood. Like you I built it out of stuff I had lying around to see if this hobby was for me. I actually just wanted to cnc cut a few bits for my model aircraft instead of by hand, and if you were careful this was possible.

However, it did go a bit oval on the circles and you could actually see it twisting a bit when cutting and changing direction. So in the end I stripped it down, chucked the wood out, sold the unsupported 20mm rails on ebay and kept all the 'good bits' for the next machine. These were the 16mm ballscrews and the 3Nm low inductance stepper motors. The following machine used more metal bits and was an improved design all round. As you can see in my signature it went on from there as you reach the limits of each machine and build a better one.

The negative tone on here is not meant maliciously - most guys on here have been there and done that and just can't recommend starting with wood / MDF. Especially when you see problems even when using all metal machines. In the end these machines fly around with lots of vibration over long periods of time and if they are not robust they can let you down just when you need them or be a pain to keep maintained / true.

As has been mentioned if you can buy some quality running gear you can keep them for the inevitable next machine once you realise just how much you can do with these new toys. Any metal you can add this MDF base will be a big help. For example metal parts for the gantry, and box section down the sides to mount the V-bearing plates to.