I'm trying to wrap my head around the 54 and 55. So G54 is after the homing and G55 is after setting all axes to material 0?
G54 is the default on switch on, G55 to G59 you have to specify in your g-code or select in your control programme (eg Openbuilds Control) although, as @David the swarfer said, your g-code file should always specify which WCS to use. Alex.
G54 is the default. power on,reset etc of the BlackBox will make it revert to G54. Similarly in CAM programs they output G54 by default into the Gcode. Anything else you need you have to set up yourself, both telling the CAM what you want, and setting up the offsets on the machine so it knows where 0,0,0 for the part is in each WCS that you are using inthe Gcode.
I use only SketchUcam for my CNC projects. It has the G54 in it. My way of operating my machine, and I've been doing it for years without any problem, is not to bother with the homing. I set all the axes to zero according to the material I'm going to machine. When I run the program the Z axis goes up, X & Y move to place and Z goes down. It' works most of the time without Z hitting the upper limit switch. Most of the time, since I mostly use 3/4" material or less but when I used a thicker material once, it hit the upper limit switch. I'm not going to start doing homing, I have no need for it, SORRY! I thought if I change the G54 to something else it will solve the problem but it looks like it will not. What will solve it?
You do need homing, everybody does. This is why.... Home, Fusion360 and G53 Z moves and this is why you get away with it most of the time.... but doing it delibrately is infintiely better, either use the switches you already have, or fake it consistantly How to 'Fake the home'