The Original Prusa MK4/S, MK3.9/S, and XL are equipped with a loadcell. This component incorporated in the hotend heatsink detects if the nozzle is close enough to the steel sheet for printing.
The only adjustment needed for the loadcell is during the selftest. After that, the first layer calibration is always done automatically during the mesh bed leveling. This avoids any damage that would be caused by the nozzle digging into the steel sheet.
The manual first layer calibration (Live Z adjust) and the steel sheet profiles are not necessary with the loadcell, as the values are checked automatically before each print.
Testing the loadcell
During the selftest, the loadcell will be tested: the printer will show the instructions for testing it.
Alternatively, the loadcell testing can be initiated in LCD Menu -> Control -> Calibration & Tests -> Loadcell Test.
During the test, you will be asked to tap the nozzle at a specific time, and a progress bar on top of the screen will be filled. If the bar is not filled or the printer shows any errors, please contact our customer support.
2 comments
Do I understand it correctly, that if I use MK4, no calibration is needed after nozzle or steel sheet replacement? Do I just replace it and start the new print? Thanks in advance.
J.
Yup :-) The loadcell will do the work for you.
Does the printer monitor the output of the loadcell during printing? By monitoring the output, the printer could automatically adjust filament flow rates, and z height to account for variability in filament diameter. If this isn't implemented I think it's worth looking into. It could help increase the quality of the prints and potentially increase the speed of the print.
Hi Brandon, thanks for the ideas, we have something similar in mind. With every technology in our printers, we want to use it to its full potential. Data from the sensor are already used to achieve the best first layer possible, and we are evaluating other use cases.
It would be a big gain in safety if the printer monitors the output of the loadcell during printing and would use this data to avoid blobs, for example.
For example, if a part does not stick to the built platform, the printer would recognize this and stop the printing process.