I am using free version Lazycam (Version3.002) & mach3 but for  some unknown reasons ,any DXF  file;
i. downloaded from this forum
ii. generated using any software that output a dxf

    cuts fine on the first pass.However on the subsequent  passes to achieve the required depth,the x & y offset by some amount

   However,all dxf files from my cad software(Autodesk Architectural desktop 3.3) goes through my unregistered lazycam software to a registered mach3 to a finished cut with no problem.what am i doing wrong here?

Can't pocket or offset with an unlincensed LC.
RICH

Am not trying to do anything offsetting.For instance,  downloaded a dxf file for spur gear the forum,used lazycam & posted gcode to mach3.The 1st pass was ok.But the 2nd & 3rd passes were off from the 1st one.There are no play in my X and Y axis. Other items designed on my autodesk cad software and run thru LC does ok thru all passes

Post the dxf file of the spur gear which you downloaded from somewhere.
Post the lcam file from LC which was used to post code to Mach. ( you will need to save it as a lcam file out of LC)
Post the g code for the file, the code exactly used by Mach to cut the file.
Post your xml file.

RICH