Silyavki, I like your idea and concept drawing and I think there will be a market for an affordable small machine that's capable of some real work. It might be difficult to do something like that on a budget looking at those big alu parts. You might consider using something more affordable for some of the large parts e.g. instead of using solid 20mm plate use two 2mm or 3mm plates epoxied to a 20mm birch ply or even mdf core. A bit more expensive but maybe bamboo ply for core? Make a piece like that and try bending it, you will be surprised how stiff it is. The laminated approach does however complicate some things because you do not have a solid core to tap holes etc but I guess there are good plans to make it work e.g. bolts right true or alu inserts in the wood core were thru holes is not feasible.