Hello everyone,

Since I got my first mill a few months back I've:

- Successfully switched my machine over from some DOS control software to Mach3 (which was the hardest step by far)
- Gained some basic knowledge about tools
- Established a few supplier relationships (for tools (bits) mainly). I now have a supplier for the cheaper HSS tools and have a company that customs makes carbide tools for me. Interestingly enough it's both faster and cheaper for me to have them made instead of ordering them to be delivered (they make them for me in 2-3 days).
- Started basic usage of the mill (mostly for cutting plexiglass/acrylic and forex/pvc foam sheets)


Things are pretty great so far and I've come a long way but there is one part in my workflow that is particularly annoying and I'm sure there is some other way to go about it.

My machine doesn't have home switches so more or less every time I add a new workpiece onto the machine I have to zero the home positions to match new workpiece. I know a lot of people will keep telling me that I don't actually have to zero all to each workpiece and that I could instead just do that with the workpiece coordinates. Here's the thing though, I like having maximum usability of the material I'm milling and usually that's within 10mm of the edge of the workpiece and since I don't have end/home switches my soft limits are based around the ref all home as well.
I am guessing however that there isn't a way around this one without installing home switches, if there is please let me know.


Now to the main issue. I don't have materials or tools setup in my CAM software (CamBam) so when I'm milling a new piece I do the following: measure the thickness of the material I am about to mill, select the tool and setup everything in CamBam. Now instead of selecting a material or a pre-defined tool I just enter the depth I want to cut, so for example if I'm cutting 3mm acrylic I just set the depth in cambam to -3.5mm and export it to g-code. Then when I import that into Mach3 I just select the x,y zeros for the workpiece, activate the spindle and jog the z so it touches the material a bit, then I just set that as the z and start milling. Mach3 will lift the tool to 3.0 with G3, go to the starting point of the cut and lower it to -3.5mm as defined in CamBam.

The problem here is, it's pretty annoying having to do this every time but that's not even the main issue. The main issue here is the all important z soft limit. I defined the z limit (soft) with one tool and set it at -57 for example, then if I change the tool then I have to change the z limit again. This quickly becomes annoying but that's not even the worse of it. I usually know right away what the issue is but my employees, who I'm also teaching to operate the mill, probably won't know the solution and will just turn of soft limits and continue machining. As you can imagine that can have serious consequences if someone made a mistake in the CAM part and it's inevitable that someone will make a mistake and that something will happen.

I think that this part can be solved with tool offsets but I have no idea how to setup these because as said, I'm pretty new to the world of CNC machining.


Looking forward to your replies and thanks in advance!