Herb
After changing the tool, it is necessary to calibrate the Z offset. Since I find it difficult to perform this task visually, I am using the following alternative technique:

I have a piece of paper that is 0.101 mm thick. I place the paper between the tool and the print surface, and lower the tool until I can just feel it touch the paper (so that I feel resistance when I try to move the paper). Then, I remove the paper, and lower the tool 0.02 mm five times. At this point, it should just be touching the print surface.
Quote 0 0
Herb
A really nice feature would be the ability to store Z offset calibration for a small number of different tools; for example Z-0.25, Z-0.40, and Z-0.80. After changing tools, the printer could then offer the option to perform a new Z offset calibration (and optionally save the values), or to load a saved set of values.
Quote 0 0
Herb
After switching to the 0.25 tool and doing Z axis calibration yesterday, I was asked to calibrate five times at four different corners of the build plate. After switching back to the 0.40 tool this morning, I was asked to calibrate at only a single point. I'm not sure what caused the different behavior.
Quote 0 0
John Kray
Unfortunately, the firmware does not support storing offsets as you mentioned.  

The paper trick is just fine and we will mention that options in the instructions/manual.

Did you select manual bed level calibration from the calibration menu at any point? That would tell the printer to use manual probing instead of the IR sensor for measuring the bed plane which it does before asking you to manually set the tool offset. If you didn't do this, I'm not quite sure why it diced to not use the IR probe. 
John
Found of Hydra Research LLC, developers of the Nautilus 3D printer and providers of 3D printing services.
https://www.hydraresearch3d.com/
Quote 0 0
Herb
Thanks, John. I did try the manual bed level calibration earlier as I was exploring some of the options. I dd not realize the connection this would have to Z axis calibration.
Quote 0 0
John Kray
Okay. Manual bed level is probably going to disappear for release.
John
Found of Hydra Research LLC, developers of the Nautilus 3D printer and providers of 3D printing services.
https://www.hydraresearch3d.com/
Quote 0 0