Mk3 so much better than Mk4 at first layer
How is it that after being out for this long, the first layer issues still plauge the 4/s
The auto cal wastes so much time, and sometimes wants to run a cleaning routine. Any ooze makes the first layer way too far off the build plate.
just the spool tension alone can cause the print head to cycle up and down without making it to the bed.
So many little quirks.
Mk3 was so much better.
IMO:
1) it should build more pressure on the load cell to read bed contact
2) it should allow you to use a preset / manual value.
I
RE: Mk3 so much better than Mk4 at first layer
I have no issues with the MK4 first layer. If the nozzle is kept clean they are good every time.
The mk3 could have good first layers too, however it took much more effort to get, and I can't think how many times I switched sheets and forgot to change it in the printer settings leading to a failed print, or even worse having an image of your part engraved on your PEI print sheet because the pei sheet is thicker than the satin sheet. Yes these are user errors, but let's be honest, we all make mistakes and your sheet is ruined.
I also had to install the nylock modification on my MK3 print beds because they were not sufficiently flat from Prusa. The standard spacers would cause the nozzle to be too close in some areas and too far away in others.
I agree though that MK3 is faster to get a print started, but it also made most people lazy on keeping the nozzle clean.
On the MK4 of you keep the nozzle clean usually a quick wipe with a microfiber towel when it preheats to 170 is sufficient. If not heat it to 230 and hit it with a brass brush and however with dry filament this is rarely needed, and usually only with PETG because it's so sticky.
Anyways that's me 2¢.
RE: Mk3 so much better than Mk4 at first layer
Issues are with .6 nozzel, on high temp filaments. The ONLY way you can get it to print correctly is with custom gcode to keep the nozel cool on probing, or manually cool it, and scrape the nozzel witha razor at the start.
Shouldnt need to do this. Should just work with the factory routine.
RE: Mk3 so much better than Mk4 at first layer
I've been recently printing with ASA and it prints as clean as PLA.
There is 1 trick though, you need to adjust the live Z when the print starts. I've found raising it .06mm is the sweet spot. I think the firmware needs to be changed to automatically change the nozzle offset based on print temperature. For PETG and PLA I never have to adjust the live Z.
I suspect that there is a default offset that's applied after creating the bed mesh. When printing hotter materials the nozzle grows more hence the reason you need to adjust the live Z higher.
In all fairness I had the same issue on the MK3. I had 2 different sheet profiles for the same print sheets, one for ASA with a higher live Z, and another one for printing lower temp materials that had a lower live Z. I labeled the profile for ASA with an A at the end so I didn't mix them up.
RE:
I did forget to add that I don't use any .6 nozzles. The stuff I'm printing I'm more concerned about quality vs. quantity, and while a .6 nozzle can be good, I didn't think it'll ever print as nice as a .4.