Nice digital calibration to calibrate your Craft Plus printerbed.
You can use just one calibration tool, but it's also possible to use 2 at the same time.
The digital micrometer: a Highly accurate digital shockproof dial indicator. Range 0-12,7mm / 0.5", 0.01 millimeter scale. Zero at any position. On off switch. Metric and Inch system to change at any position.
Available on the internet, I used this one:
PLEASE: don't forget to LIKE this design !!!
Just a HOWTO to use this nice tool:
1) level your bed in the way you normally do: with a card or paper.
2) test your printer with a calibration design (you can use this one: https://www.thingiverse.com/thing:2720578) to see if the bedleveling is ok. Repeat 1 and 2 if not corrected yet.
3) power off your printer and let it cool down totally (or just continue the next day).
4) put your bed and extruderhead to the start position.
5) place the tool on the printer-rods (see photo) and move the tool to every corner and write down the measured distance on a paper. Repeat this a few times to see if they are all the same. If not the same, make them equel by just turning the bed-knobs a little.
Just a fraction is need, because your printer was printing nice already.
6) remove the tool and print the calibration design again, it must be more accurate now.
7) if you are happy with it: keep the final measurement somewhere nearby your printer and tool.
If you need to recalibrate your printer again later, start with (3) and (4), move your bed looking at the micrometer: adjust the knobs until the measured distance in the 4 corners is equal to the distance you have noted on your paper: in just a few minutes your bed will be leveled in the optimal way !!!
I use it when I replace the bed with another one, very handy and no more hassle with calibration cards or papers !!!