A couple of quick questions. Honestly

  1. When I Zero the machine to the centre of the workpiece in CC and then export it to CM and run the program, the machine parks up away from the centre on completion, which is fine. If I then edit the file in CC (essentially I disable one toolpath and enable the next toolpath with the same start point) and run it in CM, can I use just the Zero X/Y and Z=6mm to bring it back to the start point and the machine ‘know’ it’s 6mm above the original start point and compensate when I run CM, or do I need to start at the bottom again (i.e. Z = 0)

  2. When I set the ‘Retract’ height in Job Setup, at what point will that happen every time a cut one of 160 holes in the waste board?

Thank you

Yes, the zeroes are persistent until explicitly reset manually, so the machine remembers your previous Z zero. BUT, you can only do this if you don’t change the tool in the router (otherwise, the tool length will have changed, and the memorized Z zero will have become invalid)

Yes it will happen every time the toolpath does a retract move, so make sure to set retract height to the smallest value that is compatible with your workholding solution (e.g. just high enough to clear the clamps with some margin), to minimize the time spent retracting during the cut. This is one benefit of using side clamps like the Gator/Tiger clamps: since the top surface is clear of any obstacle, you can then set retract height to a very small value (say 2mm)


Awesome. I had a panic moment with Q2 when my end mill skated across the workpiece and tried to adjust the clamp at 20,000rpm, and it was a bit fiddly resetting the Z height every time, hence Q1.

Thank you :+1:

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Even after turning the machine on and off and “initialize” ?
Also, how accurate are the proximity sensors? If the machine is turned off, turned on, intialized and it remembers zero…how accurate will the zero points be?

Yes, even after turning the machine on and off.

“Initialize machine” is the homing sequence, which will make sure that the machine starts from a known (and precise) mechanical reference, and the coordinates of the zeroes are set with respect to this home position, so the zeroes won’t be impacted by (re)initializing.

There are a number of factors impacting the re-positioning accuracy after a power cycle/homing, but I can tell you this:

  • proximity switches have a pretty good repeatability. YMMV but it’s a number expressed in tens of microns, check out this thread for (lots of) details
  • if your machine is mechanically sound, the accuracy of the zero across power cycles is negligible in 95% of the cases. It may be noticeable if you power cycle the machine in between doing something that requires a very high precision, e.g. between the cutting the two sides of a double-sided job in metal or some other material where minute positioning errors are visible.

It’s still a good habit to try and NOT power cycle the machine in between two jobs using the same zero, but if you do, it’ll work.


Ooh, even better.

Thanks for question!