So I’ve mostly hammered out my issues with cutting…I’m ashamed to say I think it was mostly because I didn’t tighten in the bit enough and it slipped up while cutting. But the question I have is around tool changes. How do people get the tool to be at the same level or location as the previous? Or do you zero out that axis again?
We recently had this discussion in another forum. It’s popular to use stop collars on bits controlling the penetration into the collet.
I am in the process of trying to find collars to put on bits that don’t come with them.
Rezero z every time I change bits. Not hard to do within .5mm and the more you do it the faster it gets.
My way is re-zero after tool change. The only exception is drilling, when a drill has a ring, as the length of the tool is not critical
I’ve been re-zeroing, it seems straight forward enough… as long as I pay attention to where my cut is. ie, I just made a coaster that went down 1 mm from the stock surface… I moved the z axis to tough that, then moved it up 1 mm, then re-zeroed since all the cuts are based off the stock surface.
Thanks, just making sure there wasn’t some other clever way to handle this.
Use M6 G43.x commands. This is a UI function. If your software doesn’t do it, request it. Believe Chilipeppr and bCNC support.
Then skip the headache and enjoy the spoils.
@donkjr great question. I have the honor of playing with a vast grouping of controllers and software. Tool changes are handled in the UI by two methods I have seen so far.
Method one: Set tool lengths and assign description and numbers. I.E. tool one is a 1/4" two flute end mill hanging out 3" for example. It is clamped in a collet that is inserted in to the draw bar. When gcode calls out T1 M6 G43 the machine stops, ask for a tool change, then G43 states to offset.
Method two (the one we use): This is really based on your controller and UI. One inserts T1 in the spindle. In the gcode we put T1 M6 G43.1 (tinyG and GRBL). This signals a dynamic tool length offset. We use the probe pins on the controller, one to the tool the other to the metallic work piece or shim if it is wood, with alligator clips.
The M6 G43.1 should tell the UI all stop, probe, offset. You can set up T1 M6 G43.1, T2 M6 G43.1, etc … All tool length offsets are automatically handled by the UI.
For example the OX plates have three tool changes. Where my code ask for this, bcnc (what I use exclusively now) stops everything, goes to the location I tell it, waits for me to manually change the tool, then probes and offsets.
@Riley_Porter_ril3y and myself recently hit up the bCNC guy to get support for TinyG. I hope more will come of this soon. It seems at one time a widget was in chilipeppr to do this.
As far as wood working and tool length offsets go (as the material is non-metallic) you can do something like the carbide3D thing and just screw something into the bed that has a flat top and tell the UI to go here for tool offset measurements. Doesn’t help with not being able to auto-level the plane but still a nice solution.
Sorry guys it looks like I may be incorrect on tool length offset in TinyG/CP. There is a pause on M6, assumed you can probe on pause, but not sure how it handles the offset, perhaps just a re-zero.
You don’t perhaps have a video on how you do this do you? I only vaguely understood what you said. lol. And what is bCNC?