Hello Guys,

currently i'm planning to build an large cnc router out of Epoxy granite or HPC/UHPC Concrete. The base should be about 3000 mm long x 1600 mm wide x 100mm high (2600x1300mm milling/working area) and there it comes to an problem where i really need your help.

Usually the mold gets filled (with epoxy granite or concrete) in "overhead-position" and when its dry it gets flipped to get an nice surface on the main side. But, what if the base will be 3000x1600x100 and weight about or over 1000 kg ? How would you flip it 180° ?

Of course with some industrial crane it is not an problem, but in my case i don't have that kind of crane, just an engine lifter (which i don't trust that it even lift more than 500 kg).

I thought to fill the mold in the position it should later be, without flipping it, and when its dry just i would use an surface plate with sanding paper to get the whole surface flat, but i dont know if that would work (for sure, but how long i would have to sand/lapp it..), The botton plate would be an 3mm steel sheet which would be mounted with screws to an steel tubing construction (all tubing filled with concrete for damping). For the side parts i would use plywood, and after the base is dryed i would take them of, but the steel sheet would be there for ever (i would use the steel sheet as mounting surface for the bolt inserts (welded to the steel sheet) for the guide rails).

Here an example how it should later look (of coursen not that thick base): http://www.q-sys.eu/images/mechanical%20bearing%205.jpg

Of course, it would be easier to build the whole router out off steel tubings, but then i have to make some stress relieving and use epoxy for leveling the guide rail mounting surfaces etc..

HPC or UHPC Concrete is quiet cheap compared to epoxy granite and it sounds like making some good epoxy granite mix is also not that easy.

So guys, do you have some suggestions for my little problem?

Thanks in advance.

Best regards,
Denis