Auto Z Position with EMC2 and Axis?
Ive just come across this thread on CNC zone and since it addresses a common issue that I have of getting Z depth consistant EVERY time, especially during tool changes with my router, I was wondering how to get something like this working with EMC/AXIS. pyVCP? The CNCzone thread is speaking about Mach3 which I dont have, nor want to.
Look forward to your comments and assistance.
well, yes and no. From my reading of it and from what I have learned from the mach3 guys who use it, its an automatic process. Lots of gcode in behind the buttons though I think. Essentially, at tool change or job start, you hit the button and the machine does the rest. Yes, a probe must be involved of course.
Here is one approach:
unfortunately it relies on using g92 .
Thank you. Having some trouble following it though
Yes John. As you know, im green at this so what "couple of lines of code" do you mean exactly. Thanks.
Ok. ASSUMING your probe is connected correctly and it is on your Z axis.
Move the probe into the XY position you wish to probe.
G38.2 Z-2 (Do a probe move with a limit of Z-2)
When the probe is tripped it will stop the axis. At that point I issue a
G91 (incremental move)
Then move my Z axis up the amout of travel it takes to trip from the time of contact. This puts my torch at Z0 Then I do a:
G92 Z0 (Set the Z coordinate offset so it is at Z0)
Lots of sparks for me, in your case lots of wood chips.
G0 Z to my safe position
G92.1 (cancel offsets and set zero)
In my case I have a floating torch head with a micro switch. Unless you have tooling that can be removed and replaced without changing the Z offset of that tool you can't do what I do exactly.
It would be a big help if you just spilled the beans and told what exactly you have/plan to do so we can stop guessing which solution you are seeking.
issue that I have of getting Z depth consistant EVERY time, especially during tool changes with my router,
How consistant does a router need to be in the Z?
The simple way to set tools that look like endmills is to have a known diameter pin. Place the pin next to the tool and move the tool low enough so the pin will not roll under the bit. move the bit up using .001" jog moves until the pin just rolls under the bit. You know know exactly within .001 the distance from the bit to the work. Just do a tool offset at that point and enter in the diameter of the pin in the offset box. Takes a couple of seconds... once you do it a time or three and no chance for damaging your bit.
To answer your question. I liked the "auto Z" concept described and would like to go to this one day. The Z depth is critical on some of the work I do with the router. Especially when there are 2 or 3 manual tool changes per job and the tools are of differing length. I hadnt thought of the pin. Thats a great idea.
Thanks again for your assistance and explaining the lines of gcode to achieve the depth. This gives me a lot of ammo to work with.