Touching off on manual tool change?

I need to make manual tool changes. LinuxCNC is promoting me for the changes as I expect but during the tool change, how can I be certain I set the tool in place in the exact height of the previous tool? Or what if the tools are of slightly different lengths? I would think touching the Z axis off again would solve the problem but the tool change dialog pops up and does not allow me to touch off the Z axis again.

I am sure this is a common issue. How do I solve it? Do I need to measure the tip of the tool to the material? Seems there should be a better way.

You'll need to break up your program into separate programs for each tool. There isn't a good way to perform manual tool changes within a program unless you have preset height tool holders (HSK, BT, CAT, etc.)

kornphlake79 wrote: You'll need to break up your program into separate programs for each tool. There isn't a good way to perform manual tool changes within a program unless you have preset height tool holders (HSK, BT, CAT, etc.)

Thanks. Will I need to touch off x and y then too? Or leave them alone?

The reason I ask is I was running a job tonight trying to get it to work just right. When I ran it a second time my x axis was off. Now am am a newb so maybe I accidentally touched off the axis or maybe pcbgode (a gcode wizard for printed circuit boards) generated the X axis differently the second time. I just want to be sure that simply breaking the job up into 2 jobs won't mess up my x/y touch off point just by loading a new job.

Wouldn't touch-off sensor solve the problem with different tool length after manual tool change ...

tommy wrote: Wouldn't touch-off sensor solve the problem with different tool length after manual tool change ...

Can you explain? The video has no audio and is not real clear.

I do have a touch off probe working. It is easy to do as I am milling and drilling PCBs. But the probe can't work nor can I touch off again because the dialog locks things out.

When you change tools you only need to touch off the z axis the x and y should stay the same.

At this point there is no provision for using a touch off probe when making an m6 tool change, as I recall there was some discussion about using a sub routine and some other m code for manual tool changes a little while ago, but I don't know if any effort was put into developing the code.

if your using pcb drills etc , they usually come with plastic collars , you can slide the collars to give you the same length
of tooling for each drill or mill bit ,
for such a simple operation for pcb milling that's the fast way , you can use the auto probe , but without a toolchanger your making matters over complicated .

once you have set your x & y in the touch off , so long as you don't switch off the machine , these points will remain
unless you change them . z is usually set to the top surface of the material , so this varies in use , each value can be set separately .

spinnaker wrote: I need to make manual tool changes. LinuxCNC is promoting me for the changes as I expect but during the tool change, how can I be certain I set the tool in place in the exact height of the previous tool?.

One way is to add an automatic tool-length measurement to the tool change routine.

This is quite an advanced topic, but it is possible, and has been done.

I think the general consensus is to keep things simple as Kornphlake suggests above. However, if you want to get into measuring automatically, I did a writeup here:
forum.linuxcnc.org/forum/38-general-linu...rements?limitstart=0
/Chris

I have a pneumatic drawbar and repeatable-length tools (BT30) all measured off into a tool table.
I still tend to put each toolpath into separate files even though I don't need to.

It makes it easier to re-do a part with a modified toolpath. It means that you can switch parts rather than tools, which sometimes ends up making more sense (ie do 1 1 1 2 2 2 3 3 3 rather than 1 2 3 1 2 3 1 2 3)
Most CAM systems make this very easy. In fact with Fusion and HSM I often do it by accident

If I need to be there to swap the tool then it's no big deal to select the next programme at the same time.