First layer issues
I used to have beautiful first layers with my MK3S.
At the start of Covid I lent my Prusa to a local maker group as part of a temporary printer farm mass-producing face shields.
They returned it about half a year later. They replaced the steel sheet and gave me a new nozzle, which I replaced.
I didn't print anything for another year or so - pandemic exhaustion.
Last November, I started printing again but am now having a lot of issues with first layers. I've attached some photos. The layer seems good around the edges, bad in the middle, especially for longer runs.
I don't know what to try next and am hoping someone here can help.
I tried drying filament, Z calibration, redoing the first layer calibration (this took a lot of tries). I bought a new roll of PETG to see if new filament would help - but nothing seems to make a huge difference.
I'm much more familiar with PLA, but the issues seem similar between both. Z calibration doesn't seem to help.
Between prints I wash the sheet with hot water and dish soap, dry with microfiber.
Since I don't have a textured sheet, I'm using a glue stick with the PETG.
In the photos, the blue is PETG (T-Glase), the white is PLA (Polymaker PolyLite). Note - I haven't dried either lately - however they are stored in sealed plastic, and these results are consistent with what I get even when I do dry.
I'm using the PrusaSlicer generic PETG and PLA profiles.
I'm wondering if the production usage of the machine could have created some belt loosening or other wear and tear? I don't notice anything in particular, but maybe it would be subtle.
I could buy some brand new PLA, to make sure I am comparing apples to apples.
RE:
One of my photos didn't show. This is default speed - the one above is about 60% speed.
RE: First layer issues
No good deed goes unpunished, right 😕
Good on you for standing up and helping your community. Well done.
I have zero experience with the smooth steel sheet, or with glue stick. So I’ll stick to what I do know and see if I can help.
i would start with a new roll of PLA as that is generally easy to print and plays nice with the smooth sheet, from what I understand, no glue stick or other release agent required. A fresh roll of a brand of filament you’ve had success with ‘should’ eliminate moisture from the equation.
The first thing I’d do is to clean the build plate with hot water and dish detergent, as you’re doing but, be sure to use a brand new unused sponge (I use the ones with one green or blue rough side) Dawn liquid detergent (in the US, Farie in the U.K. I think), no additives or fragrances, and dry with clean paper towels. Microfiber cloths are notorious for catching grease and oils and smearing them all over your freshly cleaned surface. Handle the sheet only by the edges once clean.
Next, go into the LCD menus and make sure to select 7x7 mesh bed leveling instead of 3x3.
Next, navigate to the page for the “life adjust z - my way” process and read the into. Then download the files and run the correct file for your new roll of PLA.
If you haven’t used this procedure, created by user @jeffjordan, you are in for a treat. This live z adjustment technique is far superior (imho) to the built in routine accessed via the LCD screen.
You should be able to arrive at the optimum z height for your machine fairly quickly. And hopefully this will get you printing again.
Otherwise you may need to do some maintenance like greasing the bearings, adjusting the belts, and checking that all screws are secure and pulleys are properly aligned and staked. But those are next steps, which will be needed eventually... regardless.
Anyway, best of luck. Let us know how you make out.
Your first layer Z is calibrated a fraction too low.
Cheerio,
RE: First layer issues
Thanks to you both.
I've done the live adjust process in the past, but it's been a while. I'll try again. Ordered some new PLA to be sure of the results.
I am already using 7x7 mesh bed leveling, so we are good there.
Will update when I've gone through all the suggestions.