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Author Topic: Help with Z Depth Problem  (Read 814 times)

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Help with Z Depth Problem
« on: June 23, 2017, 01:23:01 AM »
I have a home built OX CNC running Mach 3.  I am using Fusion 360 for CAD and CAM.  I am having a problem with my Z depth cutting deeper than the G-Code is set at.  I am cutting a 2D pocket that is set at -3.2mm below Model Top.  The pocket is a 7' x 3" rectangle with radius'd corners.  It is cutting starting at -3.6mm and going down the first Y travel it goes to 3.94 mm.  As it runs the first X segment it goes to 4.80mm.  As it comes back on Y it goes from 4.8mm to 4.17mm.  As it comes back on X to the starting point it goes back to 3.6mm.  The G54 machine coordinates show -3.2mm and I checked the code and it is the same.  I posted on the Fusion 360 site and a comment suggested it is a problem with Mach 3 or the post processor.  So it is staring off at -.40mm below G-code which is acceptable but not great.  It goes to -1.60 deeper than it should at the opposite corner and comes back up to -.40mm.  

I have tried everything I can think off. It is notable that my X and Y axis cuts are very accurate.  

I am cutting 19mm starboard plastic which is very flat.  The material is securely fastened to the table.
I put down a new spoil board and fly cut it to ensure it was parallel to the z plane.

Offline Tweakie.CNC

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Re: Help with Z Depth Problem
« Reply #1 on: June 23, 2017, 02:32:10 AM »
Use Notepad (or similar) to check your generated Gcode file.
Does it show a Z- depth of greater than you are expecting ?

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.