I’ve recently begun having some serious 1st layer adhesion issues after having made a handful of successful first prints with “ok” quality with my Snapmaker 2.0 A350. I’ve been 3d printing for a few years, but I’m far from an expert. So I started going through a series of calibration routines, but can’t get past the first step… because of the afore mentioned adhesion issue.
I’m using the black filament that shipped with my Snapmaker.
I’ve set the hot end to 200 degrees and the bed to 60 degrees.
I’ve ran the auto-level routine countless times… But here is something I don’t understand, Snapmakers guide says to run the calibration, use the included card and to lower the head until I feel resistance pulling it out, and it starts to curl when pushing it forward. If I remove the card completely at the point at which the card begins to curl when pushing it forward, I can’t get it back underneath the head again… -surely- this is far too close to the print bed? My previous printer was a Robo3d r1+, and the head calibration basically needed a sheet a paper to barely have any friction at all from the head. Additionally, my previous printer used a glass heated bed, which needed tape or glue to help with the adhesion. I have no idea what material the A350’s bed is, but I can’t seem to find any mention of it needing anything similar? Also Also, why is this calibration being done with the extruder and bed cold?? Won’t thermal expansion mess with these values? I’ve tried preheating the head and bed prior to calibration, but they both keep getting turned off by the auto level routine.
I’ve searched this forum several times, and keep getting brought back to the same overly complicated posts about setting up and manually managing each point in a custom 5x5 or 7x7 grid on the bed. That’s not something I have the mental bandwidth or time to do every time I want to print something.
So, basically, where do I go from here? Am I doing something wrong? I can’t continue calibrating to fix the other issues if prints won’t adhere to the bed. I’m very impressed by the build quality of this machine, but after the ridiculous wait to receive it and getting prints with various issues, I’m getting quite frustrated with it and just want the darn thing to work.
Try a different filament. The SM black has been crap for a lot of people.
Use a 5x5 calibration. Heat bed up to 5-10º higher than what you’re going to be printing at. (It can’t be on during calibration or it messes up sensor)
Most people find one less than SM recommended works best. Instead of pull/no push, go to that point and then back off one step. Don’t pull the card all the way out.
Make sure your bed is clean - use rubbing/isopropyl alcohol.
You should only need to calibrate when you change heads/beds.
Share some photos of your SM and we can take a look and make sure there’s nothing funky about it.
-S
A few points of varying usefulness:
Some spools of the filament Snapmaker shipped as a throw-in with the printers had QA problems that went undetected until people started complaining (the filament was manufactured by a third party that used Snapmaker to dump a bad lot, it seems). If you can, use something else.
There’s been a lot of argument about just how tight to the bed the calibration should be. Many people set their machines to 0.05mm or even 0.1mm higher than Snapmaker recommends.
The reversible print bed thing should have adequate adhesion without coating it with anything, but you can use glue stick, blue painter’s tape, Magigoo etc. if you like, and it may help your prints stick.
The calibration is cold because of a hardware/firmware design flaw. As of right now, the best you can do is to heat the bed beforehand to a higher temperature than you would actually use, then calibrate as it cools. Various people are trying to fix the firmware.
Beyond that, I can only suggest adding a brim or even a raft.
After I posted I had a little success with adhesion in the center using my previous method of “just barely any friction on the card” during auto leveling. I still need to test the corners again. But getting adhesion in the middle was enough to let me print a calibration cube and start with other calibration tests. I figured I’d go through them all once and then once more to see how things improved. I’ll post some pics in a little bit. I have to step away to make dinner.
Also make sure you’ve calibrated extruder so you’re not under-extruding.
-S
I’ve recently played around with PrusaSlicer and this has given me a better understanding of some things and all of them are actually also configurable in Luban. With regard to bed adhesion, my biggest takeaway was:
- print a thicker first layer 0.3mm (75% of nozzle diameter) works great for me. It also allows much better to finetune the z-offset when you’re starting to print.
- print a much wider first layer. I’ve set the width of the first layer to 1mm (using a 0.4mm nozzle) In Luban you can configure the width of the first layer in percentages. By default it’s on 100%, but I assume you can set it to 250% just as well to get that 1mm layer width.
These two more or less solved all my first layer & adhesion issues up till now. I always print a 3 layer skirt around the object and that gives me plenty of time to raise the z-offset if needed. And as the first layer is 0.3mm thick, changing it up or down a bit leaves a lot more room for playing around with that.
And the final tip. When calibrating: make sure that your nozzle is clean. it has bitten me in the ass a few times that there is just a tiny piece of plastic still sticking out. When doing the final leveling, you actually feel the resistance of that piece of plastic, and not the nozzle. If it sticks out for 0.5mm you’ll be wondering afterwards why you have to move the z-offset down so much when printing.
I always print a skirt simply to get the extruder primed, however even the skirt is not adhering. I’ll consider upping the first layer, but I don’t get a say in that in some of the pre-generated gcode while going through the recommended calibration steps on the Teaching Tech site that’s been recommended on this forum many times.
try squishing your z-offset in, making sure your sheet is clean and dust free with alcohol, and apply as much heat as you care to deal with waiting for on the heated bed (for now anyhow)
you are probably fighting with the bed not being flat too, which you can try to pre-heat your bed for about 20 minutes before runninga calibration
does your extrusion look kinda funky, like maybe if you hit the load button does it go crooked, or crackle/pop at all? is it particularly rough feeling?
Indeed, the teaching-tech doesn’t allow you to change those first layer properties. And also shouldn’t. it’s meant for calibration so the goal is to get it all just right.
My personal advice is to change the order a bit:
- start with the Extruder e-steps calibration first. almost every snapmaker that gets out of the factory under extrudes by 10%. This will also impact the first layer adhesion.
- then do the baseline print
- then do the first layer calibration
As mentioned: do make sure your bed is clean. For me as well, first prints went quite good and at some point first layer started becoming an issue (granted, I also started using different filaments at the same period, so that’s probably the main reason)
Using some kind of glue stick for adhesion is definitely an option and will help too. A lot of people do. For me it usually works out just fine without, but if you get better results with it, just use it. As you say in your first post, it’s not worth the mental health issues to worry about it and obsess of not trying to use it 
As for the filament: personally, the snapmaker filament (I got a white one) worked really well, for some people (mostly black filament it seems) they had really bad results with it and needed to get the humidity out first.
Right, which becomes a problem when the layers don’t adhere.
I was just doing the Retraction calibration though. Printing with retraction distances 1-5 and 0 z hop everything prints as it should in the center of the bed. Change the retraction to the best setting and reprint with increasing zhops and the entire thing doesn’t even print above the bed, instead printing way off to the left over the base plate… but at least it’s not an adhesion issue this time? 
Here’s my calibration thus far:
- Frame Check: Good
- PID Autotune: started, then skipped as autotune doesn’t work on SN2, and learned others have same issue
- First Layer: quality is all over the place, even within the square. Frequent adhesion issues. Skipped temporarily in frustration figuring that maybe later calibration steps might resolve some of the issues here.
- Baseline print: Turned out really well. Adhered to bed,. dimensional accuracy X 19.78, Y 19.7, Z 20.1 - darn near perfect without having made any changes yet. Some definite underextruding though as there are gaps in the top and bottom surface.
- Extruder: changes from 212.12 to 235.79
- My slicer flow was set to 90% originally per the SN provided machine profile. After increasing to 100% the average wall thickness, measured 3x/side was .428. Some sides averaged .48, while some were .37. Oddly, the high values were not both x or y axis, I had one higher thickness on one X and one Y wall, and one lower on both. Not sure how to approach that, but since the average ended so darn close, and it was better than at 90% I figure I’d leave it at its increased 100% for now.
- Stepper motor: Skipped
- Retraction Tuning: Currently attempting this. Getting best results with 5mm retraction so far and 60mm retraction speed
I use 1mm max 1,3mm. 5mm looks a bit to much for a directextruder.
uhm that would mean you were over-extruding before? (which would surprise me)
Most posts about it I’ve seen so far has a value of 235-240 for the E-steps.
As you mentioned under-extruding in point 4, and you changed the value down to 192.92, you would be under-extruding even more.
I loaded the extruder. Measured out 100mm from the top, snipped it there. Fed 100mm, had 10mm remaining. Put that in the calculator on the site and was told 192. But I guess that was being balanced in my slicer by under extruding by 90%?
its a balance to find, and slicer flow adjustments are normal, i dont think most people super duper do the e-step thing on every spool or anything
did you try to pre-heat your platform before doing a calibration by chance? at the temp you want to print at? because the frame and warps as it gets hot
See OP. Short answer: Yes for exactly that reason, but the SN2 calibration turns off the heaters, so it doesn’t stay hot throughout calibration.
correct, but the warpage and unwarpage takes some time
I would say maybe try to lower your z offset a little bit to see if you can get some sticking to do the linear advance testing
Honestly, so far, my best ABL results on the SN2 have been done with everything room temp, which from what I’m seeing on the forum here seems to be what it was designed for.
even snapmaker admits that the bed temp warps the bed and is working on a firmware update to preheat actually, but
everyone has their own experiences all the machines are a lil different and you gota learn how yours acts for sure.
The teaching tech site assumes you measure 12cm. (because if you overextrude you can’t measure by how much after it has run the test)
So in your case you would have 3cm left, which you fill in the calculator. And your calculated value would be closer to 238.
You’re under extruding even more now.