Newbie Help Please

Hello Everyone,

I am new to CNC and would consider myself am ultra Newbie. I am configuring my x y z axis and need some assistance.

Questions:
1. Is the home location, the 0 point on each axis?
2. If my tables cutting surface is x - 51", y-29", z-2.5"
then would I put the travel as 0 to 51 for the X? or would I put -25.5 to 25.5 for the X?
3. How do you set soft anf hard limits? Is there a tutorial somewhere?

Any help would be greatly appreciated. If you are locate in South FL, please don't hesitate to reach out where I would be glad to exchange my Computer Technology Knowledge for CNC assistance. Thanks in Advance!

Rob. rrbetcher at yahoo dot con

i presume this is a mill ...
it's usual to have the 0.0 x y home location at say the left front corner of your table and + ( positive directions would then be from left to right on the x axis and front to back on the Y axis ) easy way is to look from the perspective of the quill
this means that the table moves left and forward to increase , the z axis is usualy located at 0 home being the top of the retracted height , as z axis is usualy set in work being the top surface of the material being cut , therefore all z depths being negative values
once set .

soft limits are set in the INI file , using stepconf will help to set everything up , if you have not already used it , their is also a help menu showing some diagrams

Thank you for the quick response. So, where would I find the .ini file?

Also, I am using a Probotix Breakout board, but my limit switches aren't working. Any ideas? Thanks in Advance!

in your linuxcnc /configs/machinename folder
have you used stepconf to set the limit switches to the correct parrell port pin you wish to use

if possible post your hal file from your config setup

have you selected or jumpered the pullup resistors on the breakout board ?
are the switches connected between the approprate pin and ground on the breakout board ?

which probotix breakout board are you using their are a few types ?

limit switch wiring is shown here

www.probotix.com/manuals/PBX-2_manual.htm

their is also specific emc configuration information shown here

www.probotix.com/support/

Thanks for tge quick response. It is the PBX-2 board with the link in the last thread.

I put the microswitches on the corresponding axis/ grounds. I am wondering if there may be a jumper setting I am missing. Not sure.

I noticed multiple .ini folders in the cnc folder. Which ini file is it? Also, which line of thr .ini file do I edit? Is there a tutorial on this somewhere? Thanks in advance!

you would need to jump JP5 on the breakout board to pul the inputs to 5v
so then the switches should pull the pin to 0v

limit switches should be connected to
pins 11 , 12 , 13 for x y z axis

did you make a configuration file using stepconf ? it will show in the emc2/configs folder under the name used
( or under the new configuration folder of linuxcnc/configs ) dependant on which version of linuxcnc you are running

your own configuration files will be under your home directory / emc2/configs or home/linuxcnc/configs

Try some basic stuff first. Using a voltmeter, ensure that the voltage at the terminal on the breakout board goes from +5 (when the switch is not activated) to 0 (when the switch is activated.) If this is not the case:
Is the common wire ( the one that goes to all switches) connected back to ground on the "correct" side of the breakout board?
Are the switches wired properly (e.g., in parallel pairs for X and Y) for your chosen approach to limit switches?

I am just finishing my build of my first CNC machine (a Fireball V90,) so I have very recent experience of making a bunch of mistakes.


There are (at least) four approaches to limit switches:
1) wire each switch to a pin
2) wire the two switches on an axis to the same pin (3 pins total)
3) wire high limits to one pin and low limits to another pin (2 pins total)
4) wire all limit switches together to one pin.

I used the simple (number 4) approach. Which one are you using?