Hi again!
I'm in the process of learning CNC, having just retrofitted my Taig mill that I've had now for several years.
So far, I've got the machine and Mach3 operating with the correct axis orientations and scales to move correctly in both metric and imperial units. I've also designed my first part in CamBam, generated G-code from it, run the code in Mach3 on my machine, and thus cut the first part. Everything seems basically to be working fine!
Right now, I'm trying to build my overall understanding of the coordinate systems in play in my setup, if that's the best way to describe it. Can anyone suggest some good "introduction to CNC" type resources on the Internet, that might speed my ascent of the learning curve? I'm having questions like these:
-- I first set my X0, Y0, and Z0 in Mach3, to the top corner of my stock. Then I ran my program and the mill cut my part, exactly as I had expected. Then I jogged the Z axis up, and inserted a new piece of stock material to make another part. I did _not_ re-zero Z; I just pushed "Page Up" to raise the endmill out of the way, and swapped in a new blank piece of material. Then when I ran the program again, the mill happily cut the new part, up in the air above the actual stock, without returning to Z0 to start. So the program seems to be running in some sort of relative coordinate system, rather than in machine coordinates. Well I would like to learn the proper and normal way of working in this kind of typical situation.
-- What are the relationships between, and the proper ways to be using, Machine Coordinates, Work Offsets, and Tool Offsets?
-- What exactly are the normal and correct ways to be using all the mysterious buttons in Mach3, like for example "REF ALL HOME", "To Go", "Machine Coord's", "De-Ref All Axes"?
-- I'm dimly understanding that there are differences between incremental / absolute / machine coordinates in the ways the different G-codes work, but I don't have a useful working understanding right now, of how these interrelate, or how programs like CamBam use them in practice.
So I am off now to start searching around and reading; if anyone can suggest some good introductory resources, I'd love to have a look!
Many thanks--
--dave