I'm not exactly sure how to summarize the problem in the title so apologies if the title is mis-leading.
I have a machine that I converted to CNC and I'm using Mach3 as the controller to a Gecko G540. The machine is setup correctly when I work it manually. The axes are calibrated correctly for movement. When I execute G00 X1.5 the movement on the x-axis is 1.5 inches. Same on the other two axes.
I drew up a simple part in Bob Cad Cam where I'm basically pocketing 4 holes that are in a line. Simulation on in BCC runs fine and simulates what I expect to see on the Mill. I've even run the code in Mach3 in demo mode on the same machine as the cad software and it simulates correctly.
When running the code on the Mach3 of the actual mill the behaviour gets a bit odd. When running the program a movement of 0.231 " on the DRO in Mach is actually over 6 inches of travel on the table! If I restart Mach3, the machine is calibrated correctly but each time I run the program, it gets into this odd scaling problem. I am suspecting it has something to do with offsets but I can't figure it out. Hopefully someone will see the problem and point out my n00b mistake.
The code is attached but i'm including the small number of lines that cause my problem.
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O100 (DINHOLES.NC)
(DATE - MON. 05/27/2013 , TIME - 10:45PM)
(POST - MACH3 )
(T1 - 0.25 DIA. ENDMILL ROUGH)
(T3 - 0.0625 DIA. CENTER DRILL)
(T4 - 0.0625 DIA. DRILL)
G00 G20 G90 G17 G40 G80 G49 G64 G94
T1 M06 (0.25 ENDMILL ROUGH)
G90 S1800 M03
G00 G54 X2.1023 Y1.028 <=== This line is where things go wrong. The mill travels 0.231 " according to Mach but its actual distance is 6".
Thanks in advance for your help.