Prusa – Printbed Level Adjustment Knob

Some FDM printers (like the Prusa i3, and others), whether purchased assembled or as a kit, are already equiped with some auto-leveling feature, that means an automatic leveling of the nozzle relative to the printbed, in a way that the distance between both are always the same – and as little as possible. On the other hand, there are other 3D printers / kits that doesn’t have such feature. In this cases, it’s necessary to use the endstops (micro-switches that limit the axis movement) and, for fine-adjustment, screws / springs that change the height of the printbed.

In my case, the Graber i3 kit I purchased requires manual adjustment of the printbed.

The screws on the front of the printbed are easy to adjust:

 

The screwa on the back of the printbed, on the other hand, are pretty tricky:

 

Anyway, this method requires an allen screwdriver and hold the nut below the Y axis base (in order to avoid it to turn together with the screw) and:

  • Move the print head to one of the corners of the printbed;
  • Check the gap between the nozzle / printbed;
  • Move the print head to another position (far from the screw);
  • Adjust the printbed height turing the screw with the allen screwdriver;
  • Move the print head back to the previous corner;
  • Check the gap again;
  • If the gap is not OK, repeat the process;
  • Repeat the process to the remaining corners.

Not exactly easy.

 

So, I considered some possibilities and searched on Thingiverse for something ready to use. It was not surprising that I found hundreds of solutions for the same problem.

The simplest one, the one I decided to use, was to print some small knob, attatch it to a M3 nut and replace the nut under the table with it. It was also necessary to superglue the screws heads on the top of the printbed, to avoid them to turn together with the knob.

  

  

  

  

 

This setup allowed me to adjust the height of the printbed using just one hand, with the print head right over the corner. Besides make the process easier and more agile, it allowed for a better precision, also.

 

 

File for Printing

The file for printing, containing the Knob object can be downloaded from the project below, on Thingiverse.

 

Printing

Nozzle 0.4mm is enough. Smaller diameters would result in a better finished object
Material ABS: Scale in 1.01
Infill 30%
Other

 

Author

Fábio Lutz

Bachelor degree in Computer Science by UFRGS / Brazil; 18 years of professional experience on software development (Delphi/Pascal, Java, PHP, Javascript, ...
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