Tool Changes

How does everyone handle tool changes, or better yet, what is the recommended process for tool changes?

Because this is not a rigid construction, meaning the Y axis is fairly easy to move and the X axis drops when you power down. I really do see how you can maintain X and Y. I am guessing you have to reset everything to 0 which means you MUST set home at the EXACT same spot as with the previous cut.

How close to far off is my thinking?

You don’t turn the machine off. I just raise the tool (under power), loosen and pull out the router, do my bit change, then reinstall the router, lower down to the surface and then reset the zero Z coordinate. Ideally, it’s referencing the surface in the same place (usually the origin).

G92 Z0 should reset just the Z.


Because you can pop the router out it can be easier. I don’t do many tool changes though. I am lazy like that.


I know this may sound elementary, but I am trying to make sure I understand. So let’s say I am making a sign which requires a .125 flat endmill for pocketing, a 60 degree v-bit for lettering, and a .25 endmill for drilling and cut out.

At the end of my gcode for the first tool I would end with G28, then the beginning of the second toolpath would begin with G92 Z0 instead of G92 X0 Y0 Z0. Same with the second tool, physically removing the router and changing the bits. The final toolpath can end normally. Is that right?

Also, when you replace the bits is it good to just let gravity drop it to the material surface? Then do you program a pause (G04 P5000) of 5 seconds to turn on the router after it lifts to the safe travel distance?

LOL :slight_smile:

You don’t want to do a G28. That will change the origin and try to find the endstops.

Honestly, what works for me is to just navigate to X0 Y0 after the first gcode file. I use cnc.js, but G0 X0 Y0 F600 should be fine. Hopefully you’re already at your clearance plane.

Then after changing the bits, I use the software to step down until the bit just touches the surface and set the Z0 position (I also do that manually, not in the gcode). Then I start the next gcode.

There are many ways to do tool changes. This is what works for me.

I would also reconsider using a 0.25" bit in addition to the 0.125". I dislike too changes enough to just let the 0.125" do the work.

Thanks. I will change that out and let the 1/8th have fun.

Ok, so I ran the Estlcam Crown file and that worked, but then I created a test cut in Aspire 9 and opened the gcode in Repetier and added the G29 X0 Y0 Z0 line and a pause for time to turn on the tool. The router moves in the opposite directions. I have tried flipping the plugs and that does not help.

I have attached a copy of the gcode. What am I doing wrong?

celtic-cross.gcode (407 KB)

What tool path post processor should I use when exporting from Vectric Aspire 9?

How it works from estlcam gcode is how all others should work. You will never need to flip plugs. There is a PP listed on the milling basics page. If you are still having issues I suggest you stick with estlcam for a while.