Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: jeffmorris on April 22, 2008, 05:34:29 AM

Title: Z-Axis Home position - up or down?
Post by: jeffmorris on April 22, 2008, 05:34:29 AM
Should the Z-Axis Home position be up or down? I have home-built CNC router.
Title: Re: Z-Axis Home position - up or down?
Post by: Hood on April 22, 2008, 08:12:28 AM
depends, usually it is up to clear your work as you dont want it to move down into your work while referencing.
 Usually the highest off the work that your Z can move is machine zero and that means all z moves are in a negative direction with machine coordinates. Obviously when youhave work offsets you can have + and - z moves but in relation to machine coordinates they will all be negative moves.

Hood
Title: Re: Z-Axis Home position - up or down?
Post by: jeffmorris on April 22, 2008, 03:58:12 PM
Let's say that the home position on my CNC machine is 0,0,4 with the Z-Axis carriage moved up. When I run Cut2D program to create signs, etc, and load G-Code into Mach3 program, what should I do so that the CNC machine routs letters 0.25 inch deep on 0.75 inch piece of wood placed on the machine's base?
Title: Re: Z-Axis Home position - up or down?
Post by: Hood on April 22, 2008, 04:26:10 PM
OK the normal way is home your machine, the zero position in machine coordinates for Z would be the highest point and the lowest would be Z-*(* being your amount of Z travel)
. When you want to machine something your code would have z0 as the top of the material and z-0.25 would be your depth of cut. To get that to work you would jog down to your material and zero the Z DRO, this makes a work offset of the surface of your material as zero and z-0.25 would be a cut of 1/4" into the material.
Hood