Streaks after first layer
First layer seems dialled in but then every layer above that looks like this. This is enclosed 400, esun abs+, 255c, I've been through Ellis guide and I've tuned everything. PA 0.05, flow rato/em 0.98, lowered max volumetric speed down to 16.5mm^3/s.
5 Replies
That looks slightly overextruded to me. I would suggest trying to reduce your extrusion multiplier and also slightly reducing your z offset so your nozzle is closer to the bed. The lower z offset should compensate for the lower extrusion multiplier on the first layer and hopefully the rest of the print should be less overextruded.
The way you can imagine this is that if we assume 0.2mm layer heights, your current extursion multiplier is extruding enough material for e.g. 0.22mm layers. However, as your nozzle is 0.22mm from the bed instead of the 0.2mm it should be that means that your first layer looks great, as there is exactly the right amount of filament for a 0.22mm layer. On the following layers however you are trying to squeeze 0.22mm worth of filament into a 0.2mm layer, which leads to all the blobs and bulging you can see on your print.
It is ofcourse also possible, that your steps/mm on z are incorrect, so your bed is only moving down 0.18mm per layer, but that is usually much less likely.
Could this also be due to esteps/rotation distance? I had measured that previously and by default when I asked for 100mm it extruded a little over 101, and had changed the rotation distance but then I had a few issues and I read somewhere that esteps were fine to adjust but that you shouldn't ever change rotation distance cause that's based on the hardware and the physical number of teeth in the gearing. Would you suggests using the calculated rotation distance I had previously and starting from there? Or just lowering the em?
There is really nothing wrong with doing it either way. I am no expert on Klipper/RatOs but it seems like rotation distance is their equivalent to the esteps/mm setting in Marlin or RRF. Basically the extrusion multiplier in your slicer is just another way to scale this value, so functionally it does not make a difference if you adjust the esteps, rotation distance or the extrusion multiplier.
The reason people will advise to use the manufacturer provided value for esteps / rotation distance is that that value was calculated based on the steps/rotation of the motor, the gearing factor in the motor and the circumfrence of the extruder gear. Realistically that value should not change, however, as you have seen in the real world factors like the friction of the filament mean that that value will not always be entirely correct. The reason people recommend to adjust the extrusion multiplier instead is that those real world factors are different for every filament, so it is easier to just have a slicer profile for each filament with a different extrusion multiplier than to chage the esteps / rotation distance in your printer firmware every time.
You can see some of the different opinions people have about the best way of doing this here: https://discord.com/channels/582187371529764864/834389170684297248/1217389879181316096
Ok so now I'm struggling just to get the z offset. I feel like I'm chasing a moving target. I started at 0 and it wouldn't even stick all of a sudden. I bumped it down -0.04 and it started sticking finally. I bumped it down -0.01 per patch and by the time I got to -0.11 it appeared I went to low. But after pulling the patches off it looked like there was some residue on the plate so I cleaned it and tired again. This time starting at -0.06 (I hadn't saved yet). Now -0.06 wasn't sticking and I bumped it down and it started sticking. Ran all the way down to -0.15 from where I started and now I can't get that patch or the -0.14 patch off the build plate.
Solution
Ignore this above. I think I had a clogged nozzle 🤦♂️