-I want to build the cnc to be able to work aluminium and have an build volume of 500mm x 500mm. can some one tell me if is necessary to buy some specific hardware ?
500×500 is very large for aluminum. If you don’t have any CNC experience this will be difficult for you. If you look at commercial machines that is an extremely large size even for expensive machines. If you are making 500x500mm parts you are looking at waterjet or plasma cutting.
-I from Portugal, so planning to build the IE version. What is the best metallic tube to use?
What size OD tubing is available to you, emt electrical conduit is preferred for its price/performance. Stainless steel in nice but very expensive.
-Is there are an dimension calculator for the IE version?
Same for both versions. http://www.thingiverse.com/thing:948320
-What is the best bearing options: 608zz or 608-2rc ?
-Nema17 motor of 1.7A with 1/32 strepper (drv8825) have enough power to work aluminium? Is necessary to use nema23?
NEma 17 4oz/in or better
-Is there are some good opensource “sliding” software to use with the cnc? in 3d printing i use cura, but for the cnc must be different, what are the options?