# Machsupport Forum

## Mach Discussion => General Mach Discussion => Topic started by: rchavez101 on January 14, 2017, 04:46:28 PM

Title: Soft limit setup?
Post by: rchavez101 on January 14, 2017, 04:46:28 PM
I need help setting up my values for the soft limit. So when I home reference all it goes to the bottom left corner of my table. If my table goes 30"+ in X, Y directions what would I put as my soft limit values? I don't want it to travel to the left or towards me any further. Is z referenced from the top of the table surface when setting up the soft limit for Z?
Thanks in advance.
Robert
Title: Re: Soft limit setup?
Post by: joeaverage on January 15, 2017, 02:28:44 AM
Hi,
soft limits are in machine co-ordinates, if you dont' reference to a known point then the machine has no idea where the
boundaries are.

When you are setting up soft limits and confirming/testing them make sure your DROs are displaying machine co-ordinates.

You say that you are homing to the extreme left. Your X travel then should range from 0 (left) to 30' (right).
As a confirmation, home to the extreme left and carefully manual jog to the right. The machine co-ordinates should increase,
ie positive. If so your X axis soft limits would be 0 and +30'.

Follow the same procedure with the Y axis. If it is homed with the table closest to the front of the machine, then when you manually
jog in the direction of the extent of travel the Y co-ordinate will be negative. Your soft limits would be 0 and -30. If the table
homes furtherest away from the front of the machine jogging into the travel area the Y co-ordinates would be positive
and your soft limits would be 0 and 30'.

Commonly the Z axis is homed to the top of travel. In that case all your machining will be done with negative Z machine co-ordinates.
Your soft limits would be 0 (top) and -10 (extreme lowest) say. This may seem a bit backwards but it is by far the most common setup,
if you ever have the chance to fiddle with a Hass mill, thats how they do it. When your actually machining something you will be using
work co-ordinates with zero commonly the top of the material to be machined. If you want to skim the surface you would drive Z down
50 thou say ie Z=-0.05 and machine away from there.

Craig
Title: Re: Soft limit setup?
Post by: rchavez101 on January 15, 2017, 08:23:26 AM
Craig,
Thank you for the reply. That is what I was thinking but wanted to confirm that I was thinking straight.