MK4 - No bed adhesion no matter what I do
I'm so frustrated.
I just bought a second hand MK4 with 2x textured steel sheets + 1 smooth PEI sheet.
I've tried both but focused more on the PEI since I heard it's recommended for PLA and better adhesion.
So here is what I've tried:
1. Glue stick
2. Brim
3. Clean with 70% alcohol
4. Slower printing.
5. Brand new PLA (Overture Easy PLA)
6. Higher bed temp - 70C
I had an issue with stringing with my previous PLA (Torwell PLA) unless the print temp were 180-190C.
First layer I always kept at 230C.
I actually had better luck in that regard with my old Flashforge Creator Pro.
Possibly important note, at some point during the prints, I notice the printer is doing some noise like it's hitting the print at approximately the same spot every layer and I see a "bubble" being formed on one side of the brim which reinforces my suspicious that the head is somehow hitting the print.
Best Answer by Gur Telem:
My guess for why this may happen is if the nozzle is worn at an angel, then the filament would only be squished when the nozzle goes in one way but would be fine when it goes in the other direction.
Here are some macro pictures (that just strengthens my theory I think).
RE: MK4 - No bed adhesion no matter what I do
hows about trying a completely different approach
forget magic fixes and snake oil...
Simply wash the build plate with HOT Water and Dish Soap, then Rinse WELL with hot water and dry immediately with Plain paper towels and keep your fingers off the print surface...
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: MK4 - No bed adhesion no matter what I do
I tried that. Washed and dried. Still the same result. At around 34% it started clicking at a specific place at each layer. At around 50-60% it started spaghetting
RE: MK4 - No bed adhesion no matter what I do
Please post a picture of a failed print, top and bottom.
Cheerio,
RE: MK4 - No bed adhesion no matter what I do
That's a print of a 2cm diameter tube that got disconnected from the bed at around 1.5cm height.
The spool is new. I just purchased it from Amazon, it's Elegoo PLA that I opened maybe a day or two before the print.
RE: MK4 - No bed adhesion no matter what I do
Here's a coin I was trying to print. It has a ton of surface that should stick to the bed but it just doesn't.
This print is a couple of days after I opened the sealed Elegoo Rapid PLA+.
There's also this weird behaviour where each time I print this coin (assuming it doesn't spaghetti in the middle), the diameter on the bottom is less than on the top. As if it gradually wider and wider layers throughout the print.
Also, even when it does finish without issues, the top part looks terrible. I never managed to get the coin printing with the white Elegoo PLA to the end but I'm attaching an example of the top using the Overture EasyPLA.
Elegoo detached from surface:
And here's the Overture Marble PLA with the bad top surface:
OK, from the bottom up:
Your build sheet is still dirty and somewhat worn, is the other side in better condition? Repeat @joantabb's washing instructions but this time rub neat detergent into the surface, wait ten minutes and rinse with very HOT water.
Your filament is damp, I suspect this is contributing to the other problems so dry the filament and try again - do not assume that new filament is dry, it was packed dry but you have no way of knowing how well it was stored, and how it was treated in transit.
You first layer is a little too high - there are a number of possibilities but one is oozing caused by moisture boiling off damp filament in the hot end pushing out a pad of plastic on the nozzle tip and messing up the bed levelling probe.
The print that grows wider on each layer: Please save your project as a .3mf file
Files > Save Project as
Zip the .3mf and post it here. It will contain both your part and your settings for us to diagnose.
Cheerio,
RE: MK4 - No bed adhesion no matter what I do
So, I've tried what you told me.
Your build sheet is still dirty and somewhat worn, is the other side in better condition? Repeat @joantabb's washing instructions but this time rub neat detergent into the surface, wait ten minutes and rinse with very HOT water.
I've cleaned it thoroughly and according to both of your instructions. I've even repeated the process a couple of times to be sure. I forgot to take a picture before the below test print but here's the "after" pic (1).
I also tried with brand new textured steel sheet (which I know should be slightly less "sticky" for PLA) and as expected it worked even worse. Adding a picture of the steel sheet as well (3).
Your filament is damp
You first layer is a little too high - there are a number of possibilities but one is oozing caused by moisture boiling off damp filament in the hot end pushing out a pad of plastic on the nozzle tip and messing up the bed levelling probe.
Dried the filament (55C in the oven for over 6 hours) and tried again.
The bubbling indeed stopped but it seemed like the water wasn't the cause for the z offset issues. See the pics (2).
How do I recognize how a first layer being too high looks like? What would a correct first layer look like?
The print that grows wider on each layer: Please save your project as a .3mf file
Isn't a .3mf already technically a zip :-P? Here is it zipped (I guess .3mf isn't an allowed file type to upload to Prusa forums, weird).
How do I recognize how a first layer being too high looks like?
It should be fused together as a sheet - none of the second layer should be visible though it.
I believe this works - I don't have a Mk4 here to test it on ... as the print starts on the first layer press and hold the selector switch, the first layer level adjust should come up and you can dial it closer; watch for the extrusions to flatten and join together - I guess about 0.02mm closer would be in the right range.
Isn't a .3mf already technically a zip
Yes, but the forum software insists on the the filetype extension.
You are printing a little hot for many filaments, try with the generic PLA preset.
* * *
There are always pitfalls with second hand equipment, you never know how it has been (mis)treated. Print sheets do wear out but they usually have quite a long life, yours looks cleaner now; if it still won't stick the smooth sheet, *ONLY* the smooth sheet, can sometimes be rejuvenated by cleaning with acetone.
I would work through https://help.prusa3d.com/article/regular-printer-maintenance-mk4_419000
Cheerio,
RE: MK4 - No bed adhesion no matter what I do
In the sent file 3.mf, the heating of the pad is turned off! Why? PLA does not stick to a cold pad! Choose an original profile for PLA from Prusa, slice and print. Just don't touch any settings! For such a simple thing, it is not necessary! You can also turn on bed heating in the filaments tab by setting the bed temperatures to the default temperatures (60/60°C)
RE: MK4 - No bed adhesion no matter what I do
I think I sent the wrong file then 😅.
I thought maybe the bed temperature wasn't stable causing the print to shrink/expand which would cause it to release from the bed. So I thought maybe if it stays at room temperature.
I'll get home and try again with a simple object and absolute default settings.
Btw, I tried lowering the print head right when it started printing the first layer. These were the results (which I think might be better but still not "good").
I lowered it 0.02mm lower (except the circled in red which is 0.03mm lower).
Looking at the print head, I don't see anything stuck that may cause it to get such incorrect offset.
Also, @miroslav.h4, shouldn't PLA be able to print even on cold beds? I know some printers don't even head heated bed and are capable of printing PLA, no? Or would it just not stick the the PEI sheet specifically when cold?
RE: MK4 - No bed adhesion no matter what I do
To me, the z-offset clearly helped, but it needs even more.
If you are sure that the nozzle is clean, I would suspect, there is something loose in the head. I would start with checking that the hot end is properly seated.
RE: MK4 - No bed adhesion no matter what I do
To me, the z-offset clearly helped, but it needs even more.
If you are sure that the nozzle is clean, I would suspect, there is something loose in the head. I would start with checking that the hot end is properly seated.
I made sure the hotend is seated properly I believe. I loosened the screws (until the hotend was able to be taken out) and while pushing the hotend all the way in, I tightened it back.
I've printed a first layer test (just a cube of 40x40x0.2mm) and kept lowering the z offset until the lines fused. It only fused at around 0.1mm and showed no gaps at around 0.13mm. That's crazy. It's almost as if my printer skips the first layer completely.
I started a new print and from the beginning went straight to 0.13mm lower the moment it started the perimeter.
It seems like the perimeter at the bottom is even too squished but the infill seems ok now I think. At around 40% I even started lowering it some more until 0.16mm.
Should I order a completely new hotend?
Here's the first test.
1. and 2. I paused the print and then resumed it so it oozed and messed up the next row or 2.
3. This is around 0.1mm lower Z
4. This is 0.13mm
And in circles I marked some scattered gaps (which were still happening around 0.1mm lower).
This is the second test.
1. This is where the perimeter started at no offset and almost immediately I changed the setting to 0.13mm lower.
2. Seems like the perimeter is even too squished (almost as if 0.13 lower is too low?)
3. I think around here I changed to 0.14mm
4. Approximately here I changed to 0.16mm lower.
5. I started pealing it off before I thought to take a picture, it's not a defect 😅
RE: MK4 - No bed adhesion no matter what I do
My guess for why this may happen is if the nozzle is worn at an angel, then the filament would only be squished when the nozzle goes in one way but would be fine when it goes in the other direction.
Here are some macro pictures (that just strengthens my theory I think).
In your first picture #4 is getting very close - try a fraction tighter - but most prints on that base should stick ok 'though maybe not tall thin ones.
Cheerio,
RE: MK4 - No bed adhesion no matter what I do
Omg. I'm so excited I can't even wait the 5 minutes to share the photo.
about 3 minutes with a nail file to try and level the nozzle and it seems to be working SO MUCH BETTER.
The first layer looks so smooth I've never seen anything like this!
Amazing how such a seemingly small thing can cause that much trouble.
I know I should probably replace the nozzle (which I plan on doing anyways as part of the MK4-MK4s upgrade I'm ordering) but at least until then, it's actually usable with decent result.
RE:
Look at this beautiful thing (the bottom obviously). Yes I see the imperfection there but it's good enough for now I think.
For the bottom I didn't use any offset. Just straight out print with stock Generic PLA settings.
No it's not out of focus. It's just that smooth. So smooth I can barely tell (even running my nails over it) which side was the bottom and which was the top.
RE: MK4 - No bed adhesion no matter what I do
Oh wow, that is quite a damage of the nozzle... Great that you found the cause!
RE: MK4 - No bed adhesion no matter what I do
I think a second hand printer should have the nozzle checked and replaced if necessary. That's the first thing I would do just because I don't know anything about how the printer was handled by the original owner. And from your photo, it wasn't pretty and the nozzle had a lot of hours on it. I didn't advise this because I assumed the nozzle was fine. And the last print, I wouldn't get too excited there because with the file you have simultaneously increased the outer diameter of the cone that the nozzle actually creates and the printed material spreads over a larger area. You'll run into this when printing taller thin walls, where you'll wonder why your walls are thicker than you'd imagine. It follows that the only relevant solution is to replace the nozzle, and the sooner you do that the sooner you will be happy with the problem solved. And to my comment about printing on a cold pad, just one thing: Yes in the early days they did print on a cold pad, but at speeds of about 20, max 30% of today's speeds. That's why they switched to heated pads to speed up printing.
RE: MK4 - No bed adhesion no matter what I do
Thanks for the answer abiut the cold bed.
Already have a nozzle on the way.
Is there any advantage to getting Obxidian vs Brass CHT if I plan only on printing PLA/PETG?
Also, the owner gave me the printer with 20h of print time but I guess that can be reset so 🤷🏻♂️.
I'm just happy I found the cause. Since was planning on upgrading to MK4s that isn't even an expense.