I’ve had this problem off and on and really don’t know why or how to fix it.
I’ve varied the bed temp from 35 - 70
extruder temp is always 200
PLA filament, tried two brands.
Print surface: pei coated metal on glass bed
I’ve recalibrated and check the z-offset, even change it higher/lower to see if that helps. It didn’t. I did slice these in Cura, as Luban cannot slice the model it just hangs. Which I’ve found to be a common problem when printing large designs. This is a house from 3DPrintedLandscape.
to me it looks like the z-offset is to close as you can see the filament extruding around the print head.
Bottom layer: 0.24
layer 0.2
The initial print looks good, but when it starts to fill in the bottom layer it gets bumpy/lumpy and partially peals from the bed. On the second layer the head its the raised portions and rips the entire print from the bed.
you can bake it in your oven, or invest in a simple food dehydrator and make an extension ring, or get a real system for doing so.
keep your filaments in an air tight container with dessicants, and even brand new spools can be wet.
it could also be over extrusion and probably is, but the wetness makes a huge difference.
also note, if you preheat your bed at the temp you want to print at for about 15 minutes, then do a calibration you will find increased success. the plane of the bed changes with heat and it takes a bit to get there.
there are some fine tuning methods you can look into as well, on this teaching tech page
Do extrusion e-steps, linear advance, then slicer flow
the first two are going to give you more consistant line widths all in all, and then slicer flow is something to get you close to ideal and you can fine tune it from there up or down as you feel necessary.
but if you are using snapmaker filament from the box, throw it out. i saw you had 2 brands, which is good, but i would say you should at least some time try something like prusament or matterhackers to see the huge difference in quality it makes
I guess, your z is too near to the bed AND your Slicer does something confusing, do you see this little lines at the outer wall? - you have to find the cause of this first.
This is a brand new roll of filament. I took it out of the vacuum sealed bag and printed with it.
I do keep all my opened rolls in sealed bags with dessicant and a humidity strip. They are all around 10% humidity.
I soak the bed for about 30 minutes before calibrating and printing. I’ve measured as much as .5mm change in the bed height during preheating. Snapmaker reproduced this in house as well. I filed a ticket on it.
I moved from snapmaker to hatchbox, not sure where that fits on the quality spectrum. This is hatchbox.
When I calibrated my e-steps they were off by about 12%, though I’ll check that again. It does look like over extrusion. Haven’t looked at linear advance, I’ll look into that.
Besides what the others have said,
Why have you chosen to have the temp always 200?
Did you print a temp tower?
Every roll of filament has a temp it prints best at.
Not saying your problems are being caused by nozzle temp, but that’s one of the first parameters you need to figure out along with z-offset and calibrating extrusion.
I also only have issues when I print very large areas on the bed. I can print anything else without issues. they print well, stick to the bed, no elephants foot, but they don’t have a huge foot print on the bed.
yes I only do preheat, I also do 5x5, just changed to 4x4.
I also decided to loosen the outside screws of the bed heater as the center is crowned and leveling can’t fix that. I just put it back together will see if this helps. I may have to convert it to a more traditional bed with springs mounting it to the carrier instead directly mounted.
I have glass on mine which did help, but it still has issues. I agree it is a bed leveling issue.
Just went through the entire procedure again and still fails the large print. To thin is spots and too thick in others. Since it isn’t planar leveling won’t fix it.
I guess it is time to get a bunch of springs, longer screws and manually flatten the bed, provide an air gap between the heater and the cradle so it quits contorting. I’m fairly confident I can get that to work, but it ruins the ability to switch to the laser or CNC.
How did you attach your glass to the heater bed? I’ve used 3 pieces of kapton tape in the center of three of the edges. They do attach to the cradle, I guess I could try to tape only to the heater and not the cradle.
I then have a magnet on the glass that the metal plate attaches to.
Uhm, that’s exactly what the calibration/bed leveling should fix. If the bed isn’t perfectly flat, the calibration grid takes this into account and adjusts the z-height dynamically depending on where it’s printing.
Also, if you have a glass bed I don’t see how it can be not planar. Your glass isn’t perfectly flat?
All good questions. why would a flat piece of glass 1/8", using a 3x3, 4x4, or 5x5 auto level after soaking the bed at 65C for 30-45 minutes resulting an inconsistent spacing between the head and the bed?
I can measure it with feeler gauges, I can measure it with the calibration card. some parts of the bed are tight and others loose. I can measure a 0.4mm difference.
This is why I can print things with small bases without an issue, but large prints fail.
maybe there is flex in a 1/8" piece of glass. I guess I could get 1/4" and try that.
Alot of the warping comes from the aluminum platform deforming when it heats up, not necessarily just the heater or the sheet
Just want to confirm you have actually pre-heated the entire print bed via simply turning it on from the settings/jog screen.
lessening the calibration grid is not going to be helpful, the 5 x 5 is the best calibration the firmware offers via the display.
theres no question its tough to print large objects on the snapmaker 2 but what you are showing us and telling us - this should be able to be mitigated quite a bit at least.
Now, if you want to go to the next level… you can run a custom 11 x 11 calibration.
Pictures would help indeed to understand how you attached everything
What metal plate are you talking about? The PEI sheet? And “a magnet” means one single magnet?
Are you then sure the PEI sheet is perfectly flat? (and magnets might also have an effect on the inductive sensor used for calibrating the bed.
