Hello everybody,

I am in the thinking of either buying a milling machine and then doing the cnc conversion or directly building a cnc expoxy milling machine. Before doing so, I read a certain number of articles and videos for the latter one and still finding myself having a lot of queries and mysteries for it. It is especially true for me as well as most machinists who didn't come across this types of material properties, mixing compound process and precision molding and constructioning. So, would any experienced ones can help to answer and will be greatly appreciated:

1)Some articles said epoxy granite material is zero in tensile strenght and excellent compression strenght. Is this true? Or, do the structure of this material need steel construction for reinforment?

2)What is coefficient of expansion of EG? Will it be same as steel, so by molding steel beam inside it, they will expand and shrink at the same rate. How about their length dimensions after a long period of time of curing/drying?

3)For lessening in price, I also want to use concrete(ie, a mixture of cement and sand etc.)instead of using EG. By putting steel I-beams inside. In the same building configurations for the two materials to compare, how much big differences between them in view of rigidity strengths and vibration damping?

4)I saw some people successfully buiding EG machine but of a size not big enough. What is the reason for it? Can it be built bigger, something like X-travel of 600mm and Y-travel of 400mm?

5)In order to have true flatness of EG surface for mounting rail guides, they are to be molded very flat with the help of a large pricely precise granite table or machined precisely afterward. Can I do it in a rough manner? After molding, then doing the shime process and using the paste for rail guide to fill the gaps between them and the EG surface. Will this paste stick equally well on EG as on steel?

6)There is also one advantage of building a EG than buying a milling machine in market, I will save a lot of transportation cost of a heavy machine because in building EG machine, some mixing ingredients of EG and steel construction materials may be bought locally.

Thanks in advance!