Early efforts and mixed results

Having assembled the bridge, worked out how to fix the bearings etc, seeing the system move was a dream come true. 

I replaced the router bit with a pencil and manually worked out the g code to draw a smily face!

It was evident that the table wasn't completely parallel with the x axis (only a mm or so off). 

The answer was beautifully simple after discussions with those who had been there, done that. I glued a piece of mdf to the table and then set it to mill the whole table at a fixed height. 

The result was a CNC machine capable of engraving and light milling. 

Unfortunately the z axis did have some rotational wobble and this results in circles coming out as diagonal ovals/egg shapes. 

After many failed attempts to improve this I resigned myself to accepting why people shell out for real linear bearings... Grrrrrr time to start saving and hit eBay....