Whats the process from design to production?

[Matabele]

Hi all,

First post on this forum, great site with some great info. I'm really new to engineering and have just been offered a gunsmithing apprenticeship. Eventually I'd like to have my own shop and manufacture my own products.

I'm wondering though what is the procedure for using CNC? So If I design something on Solidworks for example and now have a 3D model of a part, what happens then? I've heard of programs like MasterCAM, does a program like that convert the solid model into G-Code for the CNC machine or do you have to manually create tool paths?

Any input appreciated thanks!

 

[Tony Wells]

CAM (Computer Assisted Machining) are intended to help get around hand coding the G and M codes. With a 3d model, you select a surface to machine, or surfaces with possible.....then select the tool you want to use on that surface, and a few other variables and it will create the tool path for you, supposedly in the most efficient way possible. Often, the actual code can be optimized on the shop floor by an authorized operator who knows his machine, or by an astute programmer. They are not foolproof, but can be great labor saving software.

Normally, you would have a "library" of tools set up to choose from that you could count on having on hand. You build this over time, learning just what tools you have, or as you acquire them. The big help in CAM in general lies in contouring surfaces, IMO. Once you have a solid model, or even a wire-frame, it saves much calculation and manual code entry, especially on non-uniform features. Machine tools love to cut straight lines, but with 3 or more axes, and CAM, that's all out the window.

On the machine, the tool list generated by the programmer is set up by the operator. End mills of certain styles and sizes are chosen, boring and turning tools, or whatever are all set up in the machine according to the tool number assignment in the program. After all tools are loaded, they are "qualified", or the machine is told what and where they are in reference to it's "home position", typically. Care must be exercised to make sure there are no interferences between tool, part, and machine. Speeds and feeds are determined by the programmer, but usually can be adjusted at the machine.

That's a nutshell explanation. There is more detail to it, but that's about how it goes.

 

[Matabele]

Thanks for the great explanation Tony, appreciate it! Is MasterCAM an example of that conversion software you were talking about? Are there any other programs out there you'd recommend? Any good free ones at all?