[mshamber]

Hi,

I was thinking about using epoxy granite for a precision machine I am building. It is not a CNC machine but I think the most experience on this matter is here.

The picture shows an epoxy granite base that will be used for a SLS (selective laser sintering) 3d printer. The base is 40 cm x 30 cm. I was thinking of casting it in 3 sections and bolting the sections together with cast in screws. All motors and moving parts are fixed to the granite epoxy base and it has a skin of 20/20 aluminium extrusion and sheet metal. I was thinking about using internal threaded stainless steel M8 screws. I am not sure how long they should be though or if they should go through the entire upper section from the base.

I am hoping that this would make a stable precision base for the printer. The coefficient of expansion is similar for steel and granite epoxy though the granite epoxy has a range. I plan to perform some experiments with different epoxy percentages and test the expansion vs the steel.

The mold will be laser cut steel welded together.