I was in the lucky situation of good quality prints from start until I ran into problems with the first layer.
After some tests I am back with a good leveled and offset print bed.

First conclusion:
When calibrated with the spacer card, an additional offset is still necessary. 0.3 mm seems very well, Bart mentioned 0.25 here and here

Here is a picture with three times the same print with different offsets in z. With 0.2 there was a bit of a sharp elephant foot. The walls are all in parallel, the curves are through the macro lens.
bed levelling

Conclusion and question:
For a good first layer, leveling the bed in the range of 0.1 mm is necessary.
Is there really no technical solution for achieving this? This process of calibration is very important and needs to be done all the time when necessary with a high reproducibility. With spacer card and test prints it needs a lot of time and manual work with trial and error.

We are looking for a printer in the company for some prototyping, but with this setup it is not for a professional use.

Ideas I looked for so far:

  • Laser distance sensor: disadvantage that they are expensive (100$+)
  • Inductive sensor: if it is a cheap one that only has binary output, an interaction with the firmware is necessary to control the way and stop it immediately when the state changes. Is this possible?
  • BLTouch from Antlabs. Can it be integrated somehow in a CraftBot+?
  • manual dial gauge: no logging or automation possible.

An intermediate way with adjusting the knobs while looking to a measurement output would be fairly enough.

May 22, 2017

mischl mischl
34 posts

0 replies

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