X Axis Origin Shift During Milling [2 Attachments]

Roy Emeny

Yes I had same problem a several months back, on forum as a thread about using rectangles.
System XP to Mach3 -Sable 2015.
Swapped cables to motors on X and Y and fault transferred to Y.
Swapped computers no change.
This suggested driver board but voltages on scope looked the same and the fault only occurred about every hour when it suddenly skip by about a cm always the same way, no way of capturing fault as it occurred. Tried to contact supplier about driver board without success. Could also be a software issue only relating to X axis but XP,Mach3 ???
In the end I drastically reduced the basic speed in the motor set up of Mach3 to about 50% of the manufacturers recommended speed and made acceleration more gentle.   With the more efficient version of PCB-GCODE that came out soon after my problems I found that the actual time to make the board was not changed as much as you would think - I can keep the mill cutting at about the same speed it is only the time motoring around the board at high speed while not cutting that is reduced and that is a small proportion of the total time.  With this set up it has never jumped again and I happily leave to get on with milling while I do something else!
So problem not solved but worked around and an adequate solution for my hobby usage.
I hope the above is clear as I  haven't started the system in question to check the precise terms used in Mach3.
Obviously I will be following your thread to see if a miracle cure emerges for both of us.
Good luck, Roy

On Monday, 7 July 2014, 0:04, "sdmonaco@... [pcb-gcode]" wrote:

[Attachment(s) from sdmonaco@... [pcb-gcode] included below]

Hi guys,

I have an problem with my x-axis shifting (always the same direction) during a board milling operation.  It only happens occasionally (about 1 out of 10 board designs).  I have documented the latest occurrence with the pcb-gcode preview window shown in the file Hybrid_RBE_Bot_Etch.bmp and the resulting milled pcbs shown in the file PCB Fab Error.jpg.  The GCode was verified using NC Corrector prior to doing the etch milling operation.   I am using a Probotix V90 mill with Mach 3 control software.  I have never heard any skipping steps during the milling when the problem occurs .  When I stop the job and issue a G00 X0 Y0 the mill goes to the incorrect x-axis position.  I have never seen the problem in the y-axis.  Anyone else ever seen this issue?