I received the demo and succeeded to convert the step to Gerber successfully.
When i tried to plan pcb without designer a simple circuit but with irregular components and no manufacturer file like Gerber i think fab 3000 do its part very successful but i still didn't succeed to complete the circuit because of another software called "Eagle".
Thanks for your question regarding "can i use fab3000 to build pcb that in parallel to my electrical scheme?
FAB 3000 will verify your PCB physical layout, and yes you can verify the electrical connection using the command "Netlist Comparison". You simply need to export an IPC-356 Netlist file from Eagle (or any PCB design software) and then import that Electrical connection file into FAB 3000. Here's a tutorial movie showing how to perform that task:
Thanks again, and please let me know if this was helpful.