Hey folks,

I am new to Mach3 and CNC. I recently bought a 4x8 cnc machine which runs on Mach3. When I create my art in VCarve Pro. and save the toolpath, load it in Mach, the file is not centered and neither is the cut centered in the material. I centered all elements in VCarve, but just cannot seem to get things centered in Mach. HELP! HELP! HELP! My jobs are being spoilt; material wasted.

Desperate Mortimer

Jog to where you want the zero position of your code to be then zero each axis DRO.
Hood

Thanks Hood,

But what on earth is DRO and what does it mean. I thought that when I Reference All Home that would set the Zero position.

Mortimer

Ok,
 DRO stands for Digital Read Out and in the case of Mach is all the little windows you see with numbers in them. The ones I am referring to are the ones that are the positions of the axis (X Y Z and A)
 Ref all will move the machine to your home switches and will let Mach know where the machines zero position is. This position is usually not very practical for machining and is what is called Machine Coordinates. You can however jog to any place you wish and zero each axis, this becomes your work offset zero position.
 As an example you have just homed your machine, the Z is fully up and tool is lower left of your travel, you now move 100mm  on X and Y and 50mm down on Z, you press the zero buttons and that will set the DROs for each axis to zero, you have just made a work offset. If you press the Machine Coords button you will see that the DRO change to the real position (X100, Y100 Z-50) press again and you are back to your offset position(X0,Y0,Z0).

Hood

Just to follow on from Hood - where is the 0.0.0 position in your VCarve Pro program. On a mill it is normally on the bottom left hand corner of the workpiece, with the cutter touching the workpiece.

Dont take my word for that - FIND OUT.

Then as Hood said - Ref All Home by all means, but then press the Machine Co-ordinates button so the light goes out. The DRO then displays Program Co-ordinates. Jog to where the 0.0.0 position is on your work, then zero all the DRO's.

Press Cycle start and off you go.

Just to go a move further then - if you now look at your offset table, under Config/Fixtures you will see that G54 has taken on some numbers - this is the offset from the "Ref All Home" position to your program position. You can copy this position into one of the other offsets,(say g55) and save it.

If you have a fixed position on you table for your workpiece, then to run the program on subsequent occaissions, fix in your workpiece, Ref All Home, type G55 in the MDI line (or include it at the beginning of your program) and the machine will automatically move to the correct start position.

Thank you all guys,

I will try what you all say and give you a feedback if all works. Tell me, has anyone used the Ez-Router CNC machines. That is the one I bought, a 4x8 with Mach3. Tell me something, has anyone ever  converted a drill bit to use as a ball nose cutter? Just a thought.

Mortimer