Dirty nozzle while purging fix
Hello everyone,
I'd like to share my experience with a custom start G-code for the Prusa MK4. The issue was that the hotend often oozed while heating up after the bed calibration. When purging on the left side of the print bed, the oozed filament would often touch the nozzle right before purging during the downward motion of the printhead. This led to a dirty nozzle before the actual print would start, often resulting in blobs falling of the nozzle in the 2nd or 3rd layer when the print speed kicks up.
My solution: I modified the start G-code to make the printer purge on the right side of the print bed. The fan on the left side of the hotend helps to blow any oozing to the right side of the print bed and off the edge. This way, it doesn't come into contact with the nozzle during purging.
This small change has significantly improved my print quality and reliability. Now, I can truly "fire and forget" my prints. The first layer consistently comes out clean, and I no longer need to babysit the printer at the start of each print to ensure there are no issues with nozzle contamination.
If anyone is experiencing similar issues, I highly recommend trying this approach. It's made my printing process much more efficient and worry-free.
Here is a video of it in action and the gcode I modified:
Has anyone else had similar experiences or found other solutions to this problem?
Thanks for reading and happy printing!
RE: Dirty nozzle while purging fix
Will try this. I often have layer shifts caused by „blobs“ on one of the printed objects with the mk4. Mostly when many different print objects are on the printed. I lowered the nozzle printing temp to the max (prusament petg 230°) what helped a bit, but most prints I am worrying if it has finished without layershift (always only ONE shift at completely random height and random direction).
I never have this issues on my mk35.
Thanks for your idea!