I am in the process of outfitting a large machine with a vacuum table. Actually what I will be doing is 'tiling' a 5' by 10' surface with eighteen separate vacuum surfaces each 19" by 19". So far I have not progressed any further than a model of the vacuum tiles shown upside down in the picture. The four corner holes match up with an existing 4" by 4" array of holes tapped in the machine table and the tile will be bolted down with an O-ring gasket around the perimeter so the machine table forms the bottom of the vacuum cavity. Two indents can be seen where the perimeter wall loops in and this is where venturi vacuum generators will be fitted. Each tile will have its own controlled air supply. The aim is to install these tiles on the table, face and machine the top surface grooves for gaskets with full vacuum applied so that in use the surface is as true as possible and mark each tile with its location. It will then be possible to remove the tiles for non-vacuum work and replace them in the same location and go back to the same accuracy. My goal is flat to plus/minus 0.002" over the whole surface for engraving on large areas of thin material. |