Tool and work offsets

I haven't been able to setup tool and work height offsets correctly in Gmoccapy. It's likely I'm doing something wrong so I just touchoff every tool when changing to get things going but that gets pretty time consuming. I think the main problem is I don't know what the reference 0 for the rest of the tools is. I assume the idea is to toolchange to "tool 0", then "touchoff tool Z" the empty spindle on a reference surface like a 1-2-3 block. After that touching off every tool in the table (that's in a repeatable holder) against the same surface should set the tool offset.

When setting the workpiece Z offset, I assume I should be able to use the tip of any tool in the table and that should set the workpiece Z-0 with that tool loaded and the offsets should be applied, or is this where I'm doing this wrong and one of the G-code commands should be applied?

Hmm, G43 is likely what I've been missing.

So I suppose if you touch off one tool selected from the library to the work, G43 should be active for every tool changed after that to apply it's offsets?

I did actually just setup touch plate probing in Gmoccapy and I'll say that's a must have feature there. I was figuring I'd have to buy a bunch of drill chucks to hold common drills and keep an offset. The past couple days I've been slapping bits into the quick change chuck and probing after every tool change pretty much takes the guesswork out of it.

If you have a tool in spindle and G43 active and you then change the tool by GUI buttn or MDI command, gmoccapy will take care to load the new offsets. If you use gcode file, please take care of adding a G43 after each tool change.

Norbert

newbynobi wrote:

If you have a tool in spindle and G43 active and you then change the tool by GUI buttn or MDI command, gmoccapy will take care to load the new offsets. If you use gcode file, please take care of adding a G43 after each tool change.

Norbert

Thanks Norbert,

I am still not very familiar with Gcode itself. The Auto-touchoff is something I wish I had thought to set up sooner, It makes slapping different drillbits into a single keyless chuck go much quicker. I noticed 2 things about it though:

For some reason if I run from line, it will execute a touchoff for every previous M6 that is in the Gcode. Is there any way around this?

Also, the easiest way I've found to measure "block height" with the machine is to use a tool that has a Z offset in the tooltable and touch it off to the workpiece. I subtract the current absolute Z height (while the tool is toouching the workpiece) from the tooltable offset and that is the blockheight. Is there an easier way to do this rather than touching the table then touching the workpiece?

For some reason if I run from line, it will execute a touchoff for every previous M6 that is in the Gcode. Is there any way around this?

No,this is a linuxcnc problem, because it does not realy support run from line.

[Also, the easiest way I've found to measure "block height" with the machine is to use a tool that has a Z offset in the tooltable and touch it off to the workpiece. I subtract the current absolute Z height (while the tool is toouching the workpiece) from the tooltable offset and that is the blockheight. Is there an easier way to do this rather than touching the table then touching the workpiece?

If you set it up like explained in the documentation, you only need to measure the hight from the surface of the workpiece to the table and enter that value. I use a digital depth caliper for that. It is connected through a BOBE virtual keyboard box to the computer. One button press on the caliper and the value is set?

Norbert

When using a vice it is difficult to use a direct measuring tool to easily measure the height of the workpiece. The base of the vise flanges out and the piece may not overhang. I suppose I can measure features on the vise before hand and just add the protruding face of the work. It's always easiest for me to just touch the too to the part.

you can change the complete behavior, just editing the change.ngc file.

Norbert

I have also been playing with the work offsets. I have a commercial machine. when I set my tools to the top of part I use a Mitutoyo 1" tool setter. I then set my work offset for Z to -1.000 that is what puts the tool at the top of the part. I rarely change this. In GMOCCAPY If I put 1.000 in the Z column of G54 work offset when I touch off my tools you add this number to the tool offset at the time of touch off. So if Z tool offset is -.500 you put -1.500 in the tool offset for this tool it should be -.500 the 1.000 work offset should be added at run time. This allows you to make changes to the part height at run time using the part offset without effecting any of your tool offsets. The same thing applies to touch off to a 123 block. I touch off my tools to the 123 block 2" plus 1 Inch for tool setter. I then I then touch off my Haimer to the 123 block 3". I can the touch off the top of my part add the difference to the Z in part offset and I am good to go. The tool heights never change they are always touched off to the 3" block. The Z work offset does not affect the tool touch off height or what is stored in the tool offset table. Is there a way to change this? The other thing is when I put -1.000 in the G54 Z location it subtracts it. Z is always negative. so a -1.000 work offset + a -1.246 tool offset should be -2.246 not -.246. I am using master.

Jim