This Auto tool Zero feature is unique in that it allows the cutter to be set anywhere on the table referenced to either the stock surface or the table top using the nominal thickness of the material as a reference. Lets face it the material you buy at your local store is never the thickness they advertise it at. It is either thicker or thinner but never the advertised thickness. Now you can either spend your time measuring the material thickness for each job or you can do the smart thing and by changing how you zero your machine you can get perfect depth pockets and cut right through your material without cutting into your spoil board.
How does it work?
Put simply the Macro askes for the material thickness when you zero your cutter and uses that to work out the Z height. If you sit the plate on the surface of the material then the offset is zero and the cutter will sit perfectly on the material surface . If sit the plate on the tabletop and enter a material offset of 12mm (1/2") then the cutter will be zeroed 12mm above the table top just as it would had you zeroed to the surface of a piece of 12mm stock.
What's the difference?
By using the material offset and putting the plate on the table top the cutter will be zeroed 12mm above the table top. My putting the plate on top of the stock and zeroing there the cutter will be what ever the material thickness is from the table top. Since we know that 12mm is only the nominal thickness of the stock and it will be either thicker or thinner than that you will either not cut all the way through your stock or you will cut all the way through and into the spoil board.
If you learn how to use this you will never need to measure the stock thickness again.
The video below highlights the problem with Stock thickness.
Scripts available here
Installation instructions here for both Mach3 and UCCNC
I want to thank the following people for their contributions to this project.
Big TEX who created the original Script that this is based on.
Glen Higgs for the Pre Touch Test addition
My only contribution was to add the material offset thickness and a beep.
John Revill for creating this Macro and sharing it with the Community My only contribution to this project was to make suggestions and let John do all the hard work.