Hello togehter,
i can’t get my first layer to print clean. I use the 5x5 calibration and print with PLA.
In the pictures can you see the result from the first 3 layers and the finisih model.
When i print it is also the case that the PLA holds at one corner and not at the other. If I change the Z-axis it will also hold at the other corner but the other corner will be thinner.
1 layer
2 layer
3 layer
finish model
Is a glas better then the original plate?
Regards
Michael
I’m no expert, but to me that looks like your extrusion might be off, and also your calibration.
Did you update to the 1.10 firmware first? That does better with bed auto-leveling.
Did you follow the posts elsewhere here about calibrating your extruder steps? (the ‘100mm filament length’ test?)
Clean the bed, just a wipe down with isopropyl alcohol and a cotton ball should be all that it needs, make sure it’s degreased (fingerprint oil etc can cause some adhesion ripples). Rub a little harder if you still see much difference in sheen left behind after it evaporates.
When you calibrate the starting height and run the bed auto-level map, I prefer to calibrate HOT. I use the ‘control’ page to home the machine first, set the bed to 65C and the extruder to 100-110C (nowhere near hot enough to start melting the PLA and building up any biproducts, but still build in some of the thermal movement). Then I run the 4x4 calibration. On that last point test I really dial it in to the last 0.05mm where I can still ‘pull’ 2 sheets of standard weight printer paper (actually 1 sheet folded over) forward but the paper immediately buckles, no movement at all on the ‘push’ between the nozzle and the surface.
Even with all that, the larger the print bottom area, the more likely it’s going to be a little inconsistent somewhere. Pictured is a print I did last night that’s about 150mm on the long side. Looks like my extrusion or adhesion was a little under in one corner around one of the nut holes the very first layer. (The diagonal ‘star’ pattern slightly visible is because I was printing fast, only .48 bottom (2 layers) so the 10% infill is kind of visible all the way thru.)
Once or twice I’ve let my cal point be a little easier, literally only one 0.05 calibration step higher but still ‘drag’ on the paper on pull and ‘buckle’ on push, and been displeased with the bottom layer. (I’ve only had prints totally fail to adhere once and that was something that had almost no surface area on the bottom layer and it was the 3rd or 4th since I’d actually cleaned the print surface, so my fault there.)
One last thought, a few points of that first 1 layer pic almost look like ‘steam bubbles’ you get if the filament has really soaked up some humidity. I see that sort of thing with my clear ABS on my old printer (I haven’t tried ABS on the new one yet, heard it doesn’t adhere that well to the bed so have stuck to the PLA so far…). I also have the enclosure, but probably doesn’t make that much difference on these first couple layers…
Ugh, I totally forgot a few other suggestions for you, one of which is one of my own personal bugaboos about 3D printing.
Others have suggested that the thermister (temp sensor) in the 3D print head is loose and may not be measuring consistently, which could result in your filament heating being equally inconsistent. The suggestion is to pull it out, and then re-seat it with a little thermal goop in there (like the thermal pastes you use for CPU cooling mounts in a computer).
If the filament spool is providing too much resistance to the extruder gear, your filament itself can be slipping. Even if you’ve not calibrated your extrusion this would also potentially starve the nozzle sometimes. There are several suggestions here for improving how the spool rolls - especially thru the grommet in the enclosure which also adds friction, these may help. I added one here: Question regarding the filament holder
Lastly you might have a bit of debris in the nozzle, or a partial clog. Make sure if you just park it up above the print bed, heat it up, and keep hitting the ‘load’ button on the touch screen it continues to flow evenly and doesn’t sputter or act a bit inconsistent. #5 about consistent heating can influence this too.
I get such uneven print adhesion when the nozzle is too close to the bed. The excess material gets pushed to the sides. When I calibrate, I calibrate 0.05-0.1 mm higher than standard procedure says. This is to allow for extension of nozzle and bed due to print temperatures. Your print bed actually looks flat enough to me. Also my standard tipp: print a skirt of ~3 lines - while the skirt prints, use on-the-fly controls to fine-tune Z-Offset.
Extruder Calibration!
I was seeing the same sort of crappy first layer as @michaelapp and i have been battling this since i got my SM2 in July. I should say that I am quite new to 3D printing and have tried to research a ton on this and have played with all sorts of settings. Anyhow today, I followed @rtrski comments on calibrating the bed level with the instrument hot/warm and also backing off the offset a little and man what a difference it is making. I actually aborted the same print a few hours ago because the first layer looked terrible, found this post, recalibrated the bed and started the exact same job. Night and day difference. I have never seen such a smooth 1st layer on my SM2. Not just that every layer gettign laid down looks better than it has in the past. Im excited to see how these parts come out. One last mention, i did calibrate the extruder just recently as well.
Hey, glad it helped @Marek!
I tried my clear ABS for the first time on the SM2 A250 yesterday. Repeated iterations of changing nozzle temp, bed temp, calibration offset, work speed, hairspray, blue tape, blue tape + hairspray, none bueno. Could not get the ABS to stick to the bed to save my life, it just wadded up around the head 90% of the time like there was too much space or zero adhesion. On the few cases it did adhere a little and leave a trail the trail would move as the head pulled it almost immediately.
I didn’t dare going beyond 235 (I’ve not tried the trick of adding thermal paste to the thermister hole yet, so I don’t entirely trust my thermistor to be perfectly accurate, and if its wrong with poor contact it’s going to be showing lower than the head is really at).
Have clear PLA on order now but this was my first not really working experience myself, so off to research all the other ABS posts here. (My old printer I used a glass bed with a fair layer of hairspray and ABS always stuck, even with the bed down around 50C or so…low bed temp might result in gradual release and warping during the print, but never failure to adhere at first. Obviously I’ve still got much to learn, too.
