Basic Logic for CNC Machines

IS there a documentation for basic logic of these machines? I want to make sure I dont forget anything while rebuilding my machine.

What machine? I then they are all different. There may be a few general general commonalities, but nothing is certain. Is there a generic Linuxcnc connection schematic? No, Linuxcnc is far to adaptable for anything like that to even scratch the surface of what can be done with it.

The most important idea, is safety first, and as such the E-stop logic should be simple hardware logic and not rely on any software, it is also best for it to be a normally closed circuit, that stops the machine when opened.

A simular approach is usually best for other safety related items such as limit switches, such as limits and barrier interlocks.

Todd wrote:

What machine? I then they are all different. There may be a few general general commonalities, but nothing is certain. Is there a generic Linuxcnc connection schematic? No, Linuxcnc is far to adaptable for anything like that to even scratch the surface of what can be done with it.

The most important idea, is safety first, and as such the E-stop logic should be simple hardware logic and not rely on any software, it is also best for it to be a normally closed circuit, that stops the machine when opened.

A simular approach is usually best for other safety related items such as limit switches, such as limits and barrier interlocks.

I realize that and uderstand the importance of the E-stop circuit. I was interested in a basic do's and dont's when setting up logic for starting and running a machine.

I ask because the machine I am working on is using hardware logic with relays and such and it is hard to follow as I dont have the PLC logic from this machine and their are over 100 in/outs.

A simple CNC milling machine doesn't "need" a hundred ins and outs. Although I have worked on machines that do have such large PLCs. In those cases many of those ins and outs cover things like M codes and keys/buttons for the user interface... The list can often be paired down significantly. Also the function of many can often be easily discerned by carefully studying the wiring schematics (if you have them.)

It is a big complicated job reworking a complicated machine. Good luck.

andypugh wrote:

Sounds like a lot of not-fun, but you probably need to make a table of all the inputs and outputs and what they mean.

LinuxCNC has a built-in PLC (Classic Ladder). It sounds like you will need it.

I have the spreadsheet done with all the inputs and outputs. 110 outputs and 54 inputs.
There is wire labels that are accurate, I am half way done verifying all the wires.