Mach3 and CNC3040 incorrect zero location

[RoyT]

Hi I am using Mach with a CNC 3040.
The cutter does not return to the correct zero location.
Even if I jog tback to the zero coordinates on Mach3 screen the tool is around 25mm out.
I can't find any info on how to sync Mach3 with the CNC.
Any ideas please.

[JAZZCNC]

Even if I jog tback to the zero coordinates on Mach3 screen the tool is around 25mm out.

25mm out from where.? What are you using for a Zero Reference.? How are you returning it to Zero.?
Your not mistaking Machine coordinates from work coordinates are you.?
Does the machine have Home switches.?

If your machine is setup wrong regards steps per millimetre then it won't move the correct commanded distance but it should always move back to the same Zero point it started from. If not then it's most likely it's missing steps which can be anything from incorrect tuning setup to mechanical issues.

First Check if it's moving the correct commanded distance by using MDI commands. Jog machine to middle of travel and Zero Work coordinates and make a reference mark to measure from then go to MDI screen and on the input line enter G1 X50 F500 and check it's moved exactly 50mm. If not then your steps Per are set wrong in motor tuning.
If correct then first check machine for binding or tight movement. If ok then try lowering motor tuning, often having to high acceleration will cause lost steps. If possible post the tuning settings so can see if your set to high or not.

Also check what the Kernal speed is set to, you'll find this on port and pins menu. Having this too high can cause problems so set it to 25Khz if not already and restart mach the retune motors.

Give more details of how your working and exactly whats happening.?