I noted the comment that many of these units have level issues. I have a first round machine from the Kickstarter campaign and have had similar challenges with leveling.
However, my Brother in law got one in December ‘20 and his seems much better. His has the newer, solid y-axis carriage that the heated bed screws onto (vs the “squashed frog” version mentioned in this thread that is more open).
Does anyone know if that updated carriage is the part that improves leveling for folks? If so, is there a way to order the newer one?
I have the new, non-squashed-frog carriage (SM2 obtained 2021/02) and it still has problems. The outer edges are about 0.3mm lower than the center. I don’t seem to be experiencing as much temperature-related warping as reported with the previous version, so likely the design is fixed and now there are just build/casting issues.
As documented in a different thread, I had to use a 0.015" shim on the high (350) end of the X axis. That leveled the X axis enough for a test print, so I tightened the carriage mounting screws down pretty good and after that the X axis was 0.015" high. Removed the shims and all was well. So the hardened steel shims flatted or smoothed something on the X axis carriage mount.
Hmm, anyone got any thoughts on using jack screws under the heated bed?
Basically a longer (M4 was it?) countersunk screw with two nuts: the lower nut determines the height of the bed at that mount point, the higher nut just keeps the lower nut in place when the screw is tightened. The nuts would also server to keep the screws in the bed when it has been removed for use of the other SM2 workmodes.
Downsides would be a smaller contact point for the bed (the surface of the nut, instead of the boss of the mount point), and loss of vertical space. The first could feasibly be resolved with a wide washer (or replacement of the nuts with carriage-specific spacers, but that would require some lathe work), and for the second we’re talking probably 5mm or so, not a big deal.
I have contacted support and they have asked me to remove the frame under the bed and put it on a table and photograph it.
I have also ordered two sheets of double hard tempered edge sanded glass from my local glass place. I plan to clamp the PEI Snapmaker plate on top of it (as I don’t have problems with adhesion with PEI unless it’s not level. Depending on the material I can print on glass or PEI then. I will post results. Also hooking this up to octopi to get a good graph of this mess of a bed.
Interesting idea with the glass. There is about a half-inch either side of the printing bed which could be used for clamping (Y-axis direction is of course less of a concern) and not interfere with print area.
After fighting with an octagonal brim that refused to adhere (odd problem - one specific corner seemed to double in height, irrespective of position on bed or sub-45-degree rotation of the workpiece; clearly a slicer error), I switched to using a raft (I avoid those as they often prove impossible to separate if the bed is allowed to cool) and finally have a print going again - and it looks like poop warmed up. When this finishes, I think I’ll pop in an 0.6mm nozzle.
Reading up on it, smaller nozzles only help with smaller details, in particular on top or bottom of the print. This is not the sort of thing I have to deal with; I am concerned more with smoothness of surface and dimensional accuracy. Layer height appears to be independent of nozzle size, in the sense that a larger nozzle can easily do small layer heights, it just has a higher upper-limit.
I’ve used 0.2, 0.4, 0.6, 0.8 and 1mm nozzles with this… my main issue is I have two $300 ender 2 v2 machines and I get extremely perfect first layers with those machines. I want that out of the snapmaker too. I am hoping a glass sheet with the original on top helps offset the horrible frame enough that I can get that quality. I plan to work through the support piece as well. I will be taking bed mesh reading in 25 spots before and after the glass addition and posting my results.
I used thin washers (0.1/0.2/0.3MM) to shim the bed to level within 0.1mm. Used superglue to glue washers to undercarriage for easier bed replacement between the different use cases…
Used a dial indicator for the measurements.
Only have printed PLA but I go very slow on the first layer, preheat to 70deg C and drop to 50 deg C on follow on layers… Typically print around 210 noodle temp for first layer and drop by 5deg after that…
Great results so far…
You guys are really confusing me. (Nuffin’ new there, I’m easily confused!)
I thought that the calibration business created a set of offsets to tell the SM machine where the bed was either higher or lower. So a warped bed wouldn’t matter.
Sure, but the software is only able to offset this so much… when your print bed has variances of up to 1.5mm that is very extreme and given that at least on my machine it’s impossible to get a perfect first layer it’s telling me the machine cannot compensate for the warped bed, this is a huge issue. The bed should not come with a 1.5mm+ variance in the middle of the bed to one side. No auto-leveling is that good. Even on my dedicated 3D printers, you get an auto-level, manually level the bed, then auto-level from then forward. If you move the machine, you do it over. That’s the only way to get great first layers in my experience.
OK. That makes sense. Thanks.
I think I may have struck lucky then; checked my bed with a steel rule and there’s nothing like that amount of warp. Mind you, can’t get good adhesion without hair-spray but I can live with that.
That’s pretty much what I have been doing. Then everything went south yesterday and I wasn’t able to print much of anything.
Today I took the printhead off, replaced the hot end (with one that had a .6mm nozzle), aligned the X-axis linear module on 1-2-3 blocks, re-ran the calibration, and deleted the Cura profile I had been using, replacing it with a known-good one from before I started on this particular project (a file handle I designed in openscad).
Things seem to be good now. I don’t know if something got out of whack, which shouldn’t have happened as I did not have a crash. When this simple print is done, I’ll give the file handle another go.
BTW, is it just me, or are the Replacing The Hot End writeup and videos under Support all out of date? The one piece of info I was looking for (whether the hot end though bottom out againt the extruder block, or if there should be a gap) was not there, and the procedures were clearly for a different print head.
The thing that fixed my A350…
1.) loosen the screws on your heated bed.
2.) heat the bed to 85C and let it soak for 30 minutes.
3.) ‘hand tighten’ the screws on the bed down going in a clockwise circle going from inner to outer screws.
4.) Put the PEI sheet on and do a 5x5 auto calibration.
5.) Z offset calibration in accordance with the manual.
It was night and day different in how it printed and worked. BTW, the numbers I got from M420 V didn’t look appreciably better. But, the A350 was able to compensate properly and it prints. I did make a few benchies to dial in my settings after this. I also did an e-step calibration in accordance with the other thread on this forum.
I’ve printed the quick change plates for the laser and CNC… huge objects across the entire bed and it works awesome.
Hope it helps,
1.) loosen the screws on your heated bed.
So far, I have never tightened the screws. I run them in till they touch, then back off 1/4 turn or so.
Light coat of hairspray (AquaNet Extra Super Hold) Approved by Marge Simpson!
No adhesion issues at all.
It’s not like the bed is going to take off flying on it’s own. The mere presence of the screws prevents motion in X and Y.
I have a theory that the screws are causing the warping.
The screws don’t cause the warping.
The bed frame being warped/not flat causes the warping. When you tighten down the screws then the heated bed matches the contours of the warped frame. If your frame is relatively flat, then no problem.
Your solve works because in your case (and for many others) your heated bed is flatter by itself.
For me I work from the middle out and alternating sides and tighten all the screws snugly.
Figure out what works for you and your machine and go with it.
Ok, like I said, it’s a theory. I don’t have the gear to make those measurements, but both the underlying frame as you indicate, and just tigtening the screws could warp the plate.
We learn as we go.
This worked surprisingly well. I was about to take the print head off to work on it, and decided to give this a quick go to see if it would be a better method than any of the ones I had been using.
My actual steps:
- loosen the screws on the bed
- tighten the 5/16" nuts under the bed with a small socket wrench
- heat the bed to 85 C and wait 30 minutes
- lightly tighten the screws on the bed so they are not loose
- set bed temp to 45C
- perform the 5x5 calibration
- lower the Z axis until any resistance is felt on the calibration card
- use an 0.127mm feeler gauge to confirm the nozzle height
- save the calibration
Steps 1-4 only need to be done when the bed has been removed, not on print head or nozzle changes.
The first-layer test I did came out as so:
The front edge is a bit low, but I can live with that given how quick and painless this method was.
The only downside is I had flipped the printing board over to the unused side, and neglected to gluestick or tape it. So those squares are pretty much on there until time erodes them. I centered a print job so the skirt is over the middle square, and am just printing over that now after spending a half hour trying to remove it. Forgot how awful PLA sticks to these sheets.
I am trying to understand (as a new user) what causes this. I haven’t seen that issue with PLA at all, things like the skirts in your picture only require a finger nail to pop off leaving no residue on my machine. Are you saying that even the skirts are basically welded on?
Also why are your widths of skirt different, mine are perfectly even extrusion around entire circumference? (Edit just realized the picture is low resolution and your bed lines look wobbly too, lol, so maybe that’s it.)
The smaller objects can be a real bear to get off if they’re thin. It’s hard to get the knife under them without damaging the board.
I’d probably just heat the bed up hot and see if I could scrape them off as they liquify.
Yeah tried bumping the bed to 60 and it didn’t help. And this didn’t even have time to dry, I was standing there watching it print.
The material is a matte PLA (Poly Terra) which is quite difficult to work with. The extruder gears gouge it pretty easily if you print onto air, and the stuff is goopy and runny when it extrudes. I am finding it is really showing me the flaws in my setup, which is a good thing as it is making me take the extra time to ensure everything is up to snuff. And when it prints, it’s nice stuff
The uneven skirt lines are in the corners of the mat and are due to this thing basically being the opposite of flat. I measured 0.32mm difference from left to right, and about 0.12mm from front to back - and that is not even taking into account local variations. When I print in the center of the mat, skirt lines are even - though it’s hard to tell in this pic due to light reflection in the center.
In all of my previous experiments with the first-layer test and this filament, they just pop right off. I could be running too hot or a hair (well, 0.025 mm or something) too low for a thin print like this. I don’t have this problem with the well-used other side of the mat. though I did at first. People refer to this as “seasoning” the mat, but really it’s just a matter of ruining that rough surface until it is smooth and prints just pop off.
Interesting data, thanks.
Last night i did a small print object ( 1.5cm by .5cm) and it popped of relatively easily with a twist of the object.
I didn’t remove the skirt.
This morning I have come to the bed and the skirt feels like it is welded on - i can’t really put effort into trying to get it off as my printer is heating up for another job on another part of the build plate (and tbh i bite my nails…). What I take away from this is when i take my object / skirt off after printing when bed is cooling down and at 30c its easy, pops off. If i leave bed and print to go cold over night then it seems to exhibit the issues other have said (this is based on leaving this one skirt on over night - so I declare the right to change my mind, lol)