martin54 wrote:Im not sure I understand you set up, sorry maybe it's just me but if you are homing your machine & then using this as z zero then how does the machine know where to start cutting or how deep it has cut in any material?
I've not actually got the z axis homed on my machine just the x & y axis.
My machine has three separate proximity switches for homing, one for each axis. The one that is on the Z axis is located at the top of the head assembly. When I home the Z axis from any given point, it moves upward until it moves into proximity of the switch, and then retracts off the switch a set amount( debounce, set at .050"). The controller then sets the location of the machine Z axis as Z 0.0 Any vertical movement up on the Z axis from this point would be in the positive range and any movement downwards on the machine(towards the bed) is in the negative numerical range. Being that the home location of the Z acis is at the top of its travel at this point, the only permissable movement possible is downwards(negative)
The bed of my machine is located exactly 12" below this home location, measured off a machined point on the spindle housing. When i am setting up a 3D CAD model in my CAM software to program the toolpaths, I have to locate this model in the CAM software as it is mounted in my machine.
For example......lets just say im taking a 1.5" thick piece of aluminum plate and machining a mold pocket into it. This plate material is going to be clamped down directly to the machine bed table. In my CAM software, due to the nature of my machine, I need to setup the program exactly as such. So the top surface of the plate is actually located at a Z position of -10.50" in relation to the spindle home poisition(-12" + 1.5" plate = -10.5"). Im basically just programming the machine in the CAM software to always have to move down to the workpiece, never up and over it to clear a tool before plunging in to make the cuts.
This is where I run into problems because in these programs that im demo-ing here I cannot set the top surface of my material as -10.50".
Does that help describe my situation better?
Now i know i can set up a homing switch at the bottom of the z axis travel and the program a completely different setup file that makes the machine work inthe opposite fashion i have set now but its a huge undertaking on this machine as ill haveto completely disassemble the gantry head to get a switch in place and then reassemble/align/set parallelism/etc.
Hence my question in regardsto whether the full version of these softwares can be setup to run in a negative Z number function, or am I sol nd have some machining to do on my machine