Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Joz on December 19, 2018, 04:45:36 AM

Title: Coordinates not at zero after restart
Post by: Joz on December 19, 2018, 04:45:36 AM

Hi,
When I zero my coordinates in Mach3, and turn my machine off at the end of the day, the next time I open Mach3 the coordinates are no longer at zero, but at a seemingly random number (all three axis). Why is this and how can it be changed so they are at zero when I restart? I have the "Persistent DRO's" box checked in General Config, so I'm not sure what else it would be?
Many thanks
Joz
 

Title: Re: Coordinates not at zero after restart
Post by: garyhlucas on December 19, 2018, 12:27:53 PM

Completely normal, even on pro machines unless they have absolute encoders which few do. They must be shutdown near a location and then pickup an encoder reference for exact location.

So you need to home to accurate limit switches if you want your zero reference to be relative to the physical machine dimensions. On old converted knee mill the axis had dials. I would zero the machine to the work and on a post-it note simply write down the location of each axis off the scales at the table edge and then add the position indicated by the dial on the screws. On startup I would move there and zero the DROs.

Title: Re: Coordinates not at zero after restart
Post by: ger21 on December 19, 2018, 03:30:01 PM

Try Persistent Offsets as well as Persistant DRO's.

Title: Re: Coordinates not at zero after restart
Post by: Joz on December 20, 2018, 04:10:24 AM

ok thanks for the answers - Persistent Offsets has done the trick