I am trying to make my own cnc machine from scratch. I am using arduino uno to drive the stepper motors.Will anyone please suggest me a pc software on which i could design my parts that i want to cut out. Also the software should easily communicate with the arduino and tell it what to do.Thanks.
As far as what I have done in past (a custom arduino-lilke board to manage a mill machine) you should consider the idea to separate the two things: the g-code execution for milling and the 3D design. For the design there are many software and to find the best that fit your needs I suggest to make a try to more than one. Including also some commercial products, the 3D design software mostly depends on the kind of design you have to do. For some modulated "artistical" components e.g. ArtCam maybe the better solution, but it is not affordable for mechanical components that can be designed easily with SolidWorks. Then there are very good opensource products like Blender including a plugin specific for g-code export. In my case as I have found a good Blender 6 plugin to make gears I use it for this case; also the ones suggested by fvan are good ones.
Take in account that all the mentioned software have the ability to export multiple formats of g-code and the format you need depends on how you manage it sending to your Arduino board. There are some g-code exports that may work and other that don't, it depends on how you interpret the Gnn customizable commands, the intermediate M24 stops for tool change, if you use or not drills and so on. Don't forget that also to make PCB there is an excellent g-code production plugin (developed in processing so full multiplatform compliant) that I use regularly for the PCB prototyping.
Better for us to know what are your needs, the working area size, the number of axes (suppose 3) and so on.
Some examples:
The following video shows my second Mill Machine - that with many improvements I am using actually - milling a PCB created with Eagle then converted in g-code with ArtCam. The solution was complex, almost long and not reliable. The quality was about to be acceptable but the method has been dismissed after some months just for the complexity.
The following video instead shows the first mill machine (disassembled when I moved from Italy to Spain forever 
) that was built with Arduino-like board and a custom circuit.
Enrico
As far as what I have done in past (a custom arduino-lilke board to manage a mill machine) you should consider the idea to separate the two things: the g-code execution for milling and the 3D design. For the design there are many software and to find the best that fit your needs I suggest to make a try to more than one. Including also some commercial products, the 3D design software mostly depends on the kind of design you have to do. For some modulated "artistical" components e.g. ArtCam maybe the better solution, but it is not affordable for mechanical components that can be designed easily with SolidWorks. Then there are very good opensource products like Blender including a plugin specific for g-code export. In my case as I have found a good Blender 6 plugin to make gears I use it for this case; also the ones suggested by fvan are good ones.
Take in account that all the mentioned software have the ability to export multiple formats of g-code and the format you need depends on how you manage it sending to your Arduino board. There are some g-code exports that may work and other that don't, it depends on how you interpret the Gnn customizable commands, the intermediate M24 stops for tool change, if you use or not drills and so on. Don't forget that also to make PCB there is an excellent g-code production plugin (developed in processing so full multiplatform compliant) that I use regularly for the PCB prototyping.
Better for us to know what are your needs, the working area size, the number of axes (suppose 3) and so on.
Some examples:
The following video shows my second Mill Machine - that with many improvements I am using actually - milling a PCB created with Eagle then converted in g-code with ArtCam. The solution was complex, almost long and not reliable. The quality was about to be acceptable but the method has been dismissed after some months just for the complexity.
The following video instead shows the first mill machine (disassembled when I moved from Italy to Spain forever ) that was built with Arduino-like board and a custom circuit.
Enrico
Forgot one video 
