Terrible 1st layer - bad mesh, tape or twisted frame? Vcore 3.1 300
Hi! I've been having this problem for quite a a bit of time: the first layer looks terrible on bigger prints (bigger than a benchy basically), most of the print area is fine but some spots are terribly raised and tend to hit the nozzle causing all sorts of troubles.
I also attached the mesh that leads to these prints: it's a bit bumpy because I tried fixing a lightly twisted frame (around .05 deviation) with tape getting to around .02
Belts have just been replaced and have been tightened (the problem was there before as well), IS has been tested, the rest of the printer is stock apart from the FMMM mod
This print was in PLA and I had ran temp towers, flow and PA tests for this specific filament and color: prints come out quite good (when they stay attached to the bed) but the quality of the first layer always concerns me
Does anyone have any tips? could it be due to something else rather than the mesh or my tape work? will the problem never go away unless I fix my lightly twisted frame?
29 Replies
Have you calibrate the Z-Offset?
Have you washed the bed with dawn dish soap , and avoid having any finger prints, even small ones on the bed.
Just retried doing that while heatsoaked (with my usual printing temps) and the situation seems a better!
I just did, and along with some better z-offset I noticed a nice difference:
It’s still not the nicest first layer ever, but it’s a start: any guesses on why some sections still look bumpy?
It seems like the horned is a bit low in those spots, but it doesn’t match with what I see in my heightmap
What speed is it printing the middle vs the brim ?? The brim looks great. I would guess you are going too fast and should slow it down to whatever the brim is doing
thanks for the tip! the speeds are same for both the brim and the middle, and they’re quite slow (60mm/s with like 1500mm/s2 acceleration)
I tried raising the Z-offset by a bit (0.075) and the results got a bit better: as you can see in this picture, after a pretty bad start (red area) I raised it and the results got so much better
still, the areas in orange don’t look so good
also, the brim only has horizontal/vertical movements while the inside is almost totally made of diagonal moves (and it looks worse), could this be a hint to another kind of problem maybe?
i think you might have some over extrusion, raising the z could help comp that on the first layer but you will see that to show part the first layer.
I am interested to know why you corners are faceted and not round? is that in the model?
I always feel is best to not rush your first layer, i prefer a slow 800-900 acceleration on first layer, let it go fast after the most important layer has been laid down.
i will show the photo to my friend and will see if we have anything els for you
Double Check wheather your magnetic bed and the underside of the spring steel sheet are clean
Generally bed meshes show a gentle curve becuase the bed is never fully flat. However yours looks like the moon surface. Maybe some dirt particles got under the bed or there are some bubbles from applying the magnetic bed.
also make sure the x and y offset of your probe to nozzle are spot on, that could improve the results you get from applying the mesh
What do you mean you fixed your lightly twisted frame with tape? Usually you adjust for a twisted frame with skew correction, not by modifying the bed.
How did your mesh look before adding the tape?
yup that's the model fault so no worries
acceleration is currently at 1500, I'll try lowering it to exclude that factor but my guess is that it doesn't have a huge role in that
that weird mesh was 100% due to the tape I applied, I removed it a few days later to try and solve the issue in other ways and now it's way worse in terms of deviation, but at least it's more of a gentle curve as you said:
I totally need to take a look at that
basically, I have a twisted frame as you can see in the latest pic I posted: since the high spot I highlighted as "D" doesn't move more then 0.01mm even after removing the right screws and trying to bash point A down with a hammer as seen in the usual video guide everyone mentions (can't figure out why) and the Y rails have like 3-4 stripped screws each from the previous owner who tightened them too much, I figured that tape was my only option to try and fix the mesh.
unfortunately, it's hard to apply properly and the result was that wobbly mesh you pointed out in the very first pics
after REMOVING the tape, it looks like the pic I just sent
0.4mm of deviation afaik is a lot for a 300mm bed, and it looks like a frame issue more than a bed problem so you're totally right, I just used tape since I had no other choice
thank you so much for the support by the way! another person suggested that I could use 0.1mm shims on the rails to lower the peak in point D, but as I said, stripped screws prevent me from removing the rails easily
Ah yea thats kinda what I expected from a twisted frame.
To be honest I think theres no (good) fix other than getting your frame squared up. I guess you saw the tutorial on how to fix the twisted bed / frame?
If you cant move down a, I think you can lift D, or try to fix the other side which should help as well. Cant remember exactly but basically follow the tutorial on which corners to adjust.
I think on my machine i also couldnt move one corner down as the extrusion for the electronics panel got in the way, so i lifted the front corner up and got it nice and square.
maybe try to loosen the screws more if the extrusions dont move?
have a look if you can find something to extract those stripped screws. Having them screwed on too tight is not good. Worse on the x-gantry but also on y its not ideal.
I wouldn shim the rails tho, rather adjust the frame.
I know, unfortunately
I saw the tutorial several times at this point lol, and even checked the official commissioning guide again for a double check: given those A,B,C,D points I highlighted in that previous pic (just like in the video), I should either hammer A down or lift B up, but none of those strategies worked
for example: after hammering A down like 5-10 times with quite a bit of force it moved down 0.01mm which is basically nothing since it would have to move by 0.2mm, and I was already using a lot of force in each hammer hit
I haven't touched C and D since I read they're basically impossible to move due to their position and the electronics panel
I have just bought drill bits for screw removal, but since it started printing decently again I really don't want to risk damaging the rails or the extrusion now ahah
@Oskait it might sound dumb but how did you exactly manage to lift one corner up? as I said, I've already tried as the video mentions (and I always unscrew the necessary screws completely) but I had no luck
Yea fair enough, don’t fix it if it ain’t broke 😅
It was over a year ago, don’t rember exactly.
When the back don’t move down because there is an extrusion in the way is to be expected, the front corners should definitely move!
What I think I used a compilation of hammering but also using clamps to move the extrusion.
When your screws are too loose, the extrusion might spring back up when hammering it down.
So getting the screws loose but still tight enough so the extrusion won’t move back or using clamps and tightening the screws before removing the clamp could help
Also maybe loosening the screws slightly on the other side might help?
To be honest it was anpain and took a long time and a lot of meshes. Try different techniques, and don’t whack it too hard 😅
just to be extra sure, you did NOT touch the screws inside this metal part circled in red right?
as the guide mentions, I just unscrewed the ones I circled in blue here to lift the extrusions up/down (and the one on the top that I cut out of this screenshot)
also, which kind of clamps did you use and how, practically speaking?
No definitely not.
I think I only touched the front tbh
Ah sry that is the front. I have the enclosure 2 so it looks a little different.
Just some long c-clamps as I wasn’t comfortable hitting it with a hammer
With the enclosure I could use the top extrusion as counter piece to pull against.
U might have some luck loosening these screws as well.
But to be honest I’m just guessing at this point. Might be bad advice as well I’m lacking the experience here
And try to hold the extrusion in place after moving so it doesn’t move back. Clamps, a strap or just stick a piece of wood underneath.
@Oskait ohh now I see, I was wondering what you were pulling against
I've mostly focused on trying to hammer down point A as seen in the pic, since I fount it basically impossible to lift up the extrusion on B by hand (or by hammering it from below, which is a mess since I have to avoid hitting the Y rail on the extrusion)
I have some crappy clamps to try, or some wood that I could place to keep it lifted before I screw it back in
I guess those screws only have something to do with the extrusion on the top/front (the one that's perpendicular to the ones with the Y rails, and parallel to the one with the X rail) so I'm not sure it would help
point is, I've never seen ANYONE mention the amount of force required to do this job
and I don't know if I'm just being worried over nothing (and those parts can withstand a ton of force) or maybe the previous builder tightened some screws too much
Honestly it shouldn’t require a lot of force.
You don’t want to bend or dent the extrusions.
Try to find where it is stuck and maybe loosen a couple more screws
I used the clamps cause it gave me more control, the hammer moved it to much and unpredictable.
I didn’t use them to exert more force
Well you said the rail screws were stripped. Sounds like they made everything super tight
yeah that's most probably the cause, like, even removing the screws mentioned in the commissioning guide I can't see the extrusion move even slightly
Guess I'll have to check some other screws and make them a bit less tight on one side first
Sounds like you should rebuild the whole thing 😅
I feel like I'm just avoiding the unavoidable at this point lol, but unless it has serious issues, I would like to postpone a full rebuild since I have barely any free time to tinker with it at the moment
but at least now I know for sure that something is wrong with how tight the screws are so thanks!
Yea fair.