Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while  

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

and I swear I have to warm mine up.....
my short theory is. I swear the "pinda probe temperature sensing" is abit off. and that offsets Z heights by a little depending on the temperature. somewhere on the forums someone has dug into it ALLOT more, and gone all nerdy with a solution.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

In my case it's not the Z-height. I've tried to calibrate Z during this condition and there's no height that works. Either the print doesn't stick well to the bed or the nozzle is so close that it leaves marks on nearby traces and rips them off. Do you have a link to that 'nerdy solution'?

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

this is not the one I was looking for but it's close.

https://shop.prusa3d.com/forum/improvements-archive--f85/pinda-probe-live-z-calibration-z-offset-and-temper-t2048.html

https://help.prusa3d.com/l/en/article/zy93f2yltv-manual-temperature-calibration

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

tl;dr: rinse your build plate with washing up liquid (for washing dishes in the kitchen) and warm water. I use Lidl stuff.

I've noticed similar problems - prints are going great, and then suddenly nothing sticks. And it has nothing to do with z calibration. I have calibrated my bed mechanically (centre has standoff, surrounding have stiff springs, similar process to this). I've noticed up to 1mm z distortion that settles as the heat from the bed spreads to the Y frame, so I try to let the bed sit hot for 20-30 mins before my first print (and keep it hot between prints). Then I run a level check from octoprint and verify that I've got < 0.05mm total deviation (typically < 0.03mm). I also use custom start gcode to wait for PINDA to reach 35 before mesh level for each print. I can then get a perfect full-plate first layer. I sometimes need to print a lot of very thin parts that must be very flat, so this is vital.

Anyhow - despite all that - sometimes PLA (or even PETG) just won't stick (I have the standard Prusa double-sided smooth adhesive PEI spring steel sheet). My understanding is that IPA and even acetone will not remove/destroy certain substances - sugars, for example. So if you've touched your build plate with less than perfectly clean and degreased hands, you can transfer contaminants. Then when you "clean" the build plate with IPA, you just wipe the contaminant all around. So while IPA, and occasional acetone (not too often or you can cause damage), are great most of the time with PEI, sometimes I find that washing up liquid and warm water is needed - wash it in the sink with running warm water, make sure your hands are well washed too, and dry with lint-free disposable cloth (not the towel that's just hanging there). For PLA, that's it. For PETG, I spread around a squirt of Lidl glass cleaning spray and let it dry on. I always follow this routine before doing any full-plate printing for peace of mind.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

I started having PLA prints popping off and I have cleaned the PEI sticker sheet with IPA and Acetone and still random PLA popping off. I finally cleaned it with a softscrub sponge, the blue ones you can buy at any store, and baking soda. After that the PLA started sticking all the time again. I think every now and then you have to rough up the service a little bit. I saw a video of Joseph Prusa using sand paper on one but I didn't want to go that far so I remembered I use Baking Soda to clean my glass top stove and it worked.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

I started having PLA prints popping off and I have cleaned the PEI sticker sheet with IPA and Acetone and still random PLA popping off. I finally cleaned it with a softscrub sponge, the blue ones you can buy at any store, and baking soda. After that the PLA started sticking all the time again. I think every now and then you have to rough up the service a little bit. I saw a video of Joseph Prusa using sand paper on one but I didn't want to go that far so I remembered I use Baking Soda to clean my glass top stove and it worked.

Do you think the baking soda trick would be OK for the PC sheet also? Is it rubbed on wet or dry?
thanks
Texy

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

My initial tests (prints) on either side of the PEI steel plate: 1) i had to slightly rough up the surface with a light rubbing of Scotchbrite. 2) cleaning with IPA. after a couple of prints with ABS and Nylon, (glue stick used) i had to use acetone. nothing was sticking in that glue stick area. Even after cleaning with soap and warm water and IPA.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

I'm having the same exact issue! All night long, can't get any pla to stick. Sheet is well cleaned. Not a z height issue.

I gave up for a few hours, went back to try again, and boom, prints are sticking again. Wtf?

Makes no sense.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

Which buildplate are you guys using? I have an older sticker sheet with the gold PEI, never heard of that being an issue and never had it personally. I was surprised when a buddy bought one since me and it had a very dark, near black sticker. I dunno, just looking for ideas at this point. And as I have mentioned in other threads before I am a monstrous proponent of using the white pad scotchbrite (7445 pad) and ISO alcohol after every print. The white pad doesnt destroy the pei sticker at all and everything grabs great. Never had issues with PETG or PLA since I began the scrub method. I have yet to use acetone on my plate at all and only did the dawn dish soap thing like once the first week I began printing before I brought a pad home from work to try out. I have found that after many many scrubs you do want to get a new pad.

I think I even saw someone else mention using the 7445 pads since my initial post (not saying I gave them the idea, no clue there) so I know I'm not the only one. It's about the only really helpfull thing I found on my own and didnt get from the great help and support from trolling these forums for hours.

TL;DR
what color plate do you have if you have these issues?
try 7445 pad with iso.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

Which buildplate are you guys using? I have an older sticker sheet with the gold PEI, never heard of that being an issue and never had it personally. I was surprised when a buddy bought one since me and it had a very dark, near black sticker. I dunno, just looking for ideas at this point. And as I have mentioned in other threads before I am a monstrous proponent of using the white pad scotchbrite (7445 pad) and ISO alcohol after every print. The white pad doesnt destroy the pei sticker at all and everything grabs great. Never had issues with PETG or PLA since I began the scrub method. I have yet to use acetone on my plate at all and only did the dawn dish soap thing like once the first week I began printing before I brought a pad home from work to try out. I have found that after many many scrubs you do want to get a new pad.

I think I even saw someone else mention using the 7445 pads since my initial post (not saying I gave them the idea, no clue there) so I know I'm not the only one. It's about the only really helpfull thing I found on my own and didnt get from the great help and support from trolling these forums for hours.

TL;DR
what color plate do you have if you have these issues?
try 7445 pad with iso.

The newest smooth sheet which is black.

I don't think the answer is making the sheet rough with sandpaper or whatever. Because the sheet was working fine and prints sticking well for several weeks. And then out of the blue, they stopped sticking. But here's the real funny part. All this time I've only printed on one side of the sheet. I flipped the sheet over to the other (never been used before side) and it's still not sticking. So it's not a PEI wear and tear issue...

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

Which buildplate are you guys using? I have an older sticker sheet with the gold PEI, never heard of that being an issue and never had it personally.

I have access to printers with both versions and I have noticed the issue on both.

It's not that the plate needs to be roughen up, as imminently after starting the printer it works absolutely fine. I haven't got time yet to do any extensive testing but right now I have two hypotheses:
1. Something happens to the plate after it is kept hot for a prolonged period of time without printing anything (but that would be extremely strange)
2. IPA cleaning (only on a heated up plate?) leaves some sort of residue that needs significantly longer time (>5 minutes) to evaporate fully

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

[...] 2. IPA cleaning (only on a heated up plate?) leaves some sort of residue that needs significantly longer time (>5 minutes) to evaporate fullyWhat sort of IPA? You want 91%+. Any lower will be less effective. Do watch out for any cleaner that isn't 100% acetone or 91%+ IPA as some do include anti-streaking agents and other impurities that can mess up adhesion.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

OK, good it seems its not the sticker in either form then. I'm at a loss, but I do want to point out that the white 7445 doesn't "roughen" up the PEI surface. My buildplate has over 50 days of print time on it and its only small blemishes were all my fault. The PEI is definitely tougher than the white pad. That stuff can easily be used on delicate hands. So don't imagine a scuffed up, scratched or dingy looking build plate. I don't think it even touches the PEI, I think it just gets the plate more or less super clean.

Well, I hope you try my idea, because it works quite flawlessly for me, if not, good luck and happy printing!

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

I have had the same problem. I could not clean the build plate well enough for anything to print and stick. My prints would not stick no matter what I did. Many times the print would come up mid print with raft, brim, or whatever support I was using. I was at the point of not printing with the PRUSA and putting it in the closet. This just did not seem like a viable option since the PRUSA gives me flawless prints when I can get the prints to stick and was more expensive than all of my other printers.

Call me stupid, but out of frustration one day, when I was ready to give up, there was an Elmers glue stick in my classroom. I thought what the heck. I put a thin layer of the glue stick on the plate and my prints did not budge. I was worried about what damage this might do to the build plate, but I did not have anything to loose. I wasn't getting to use it anyway. When the print was done, I took a towel and alcohol and the glue residue came off easily. I have experimented with going 2 and even 3 prints and the glue stick comes off.

I am in no way telling anyone that this is their solution to prints not sticking but I am 150 hours in and my build plate still comes clean and my prints stick every time.

For what it is worth.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

I started having the same issues. Tinme to try the baking soda and blue scribber.

Re: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

Just in case somebody runs into this post in the future:

Hope this helps someone.

RE: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

Boy, am I glad that I found this topic.

My prints were coming out okay, but my first layers were looking a little rough, so I spent about a half hour dialing in the "Live Adjust Z", until I had a close-to-perfect first layer.  Then, before I started my print, I wiped the surface (I have the powder coated steel sheet) with 91% IPA.  Of course I should do that - Jo Prusa cleaned the surface 3 different times in his new user video and said that I should clean before every print.  (Better order some IPA from Amazon...)  Finally, I started what I expected to be a perfect print.

ABSOLUTE GARBAGE!  The skirt didn't stick, the outer perimeters didn't stick, and the rest of the first layer curled up at the edges, up to about 5mm high, which caused lots of filament to stick to the nozzle.  I stopped the print and cleaned the nozzle.

Dejectedly, I searched the forum and found this topic.  I then cleaned the sheet using hot water, a couple of drops of dish washing liquid, and a dish washing brush.  I dried the sheet with some paper towels, then tried my first layer test again.

Perfect.  Started my actual print - perfect first layer.

Now I'll I have to do is figure out what I'm going to do with the case of IPA that I ordered on Amazon.  I guess when the zombie apocalypse occurs, I can trade infirmary services for filament and electricity, so that I can continue my 3D printing addiction.

Thanks for the help guys.

A.J.

P.S.  One thing I may have done wrong was to wipe with IPA with the surface still warm.  In the guide that came with my MK3S, it said that might cause the IPA to evaporate before it did much cleaning, but it sure DIDN'T say that the IPA would leave a residue that would screw up my print!

RE: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

One problem with IPA is it does just as good a job lifting oils from fingers as it does lifting oils from the print surface.  Gloves keep the oil on your fingers, and gives the IPA a chance to move some of the oil off the bed.  But, you must remove all of the IPA (and dissolved oils) before any evaporates, leaving  -- what else? -- all that oil behind.  So lots of alcohol, scrub quickly; sop it all up with clean fresh paper towels BEFORE any evaporates.

Option 3:: don't put finger prints on the bed in the first place.

RE: Prints don't stick to PEI after cleaning but start sticking after the surface rests for a while

Two source of contamination to consider ...

Did you change paper towel roll or cleaning cloth? Some seem to be impregnated with softeners that are not so good for bed adhesion. IPA would simply transfer that to the print plate.

Did the IPA touch your hand during the cleaning process? That transfers hand oils to towel, especially if you flip the towel during wiping. Ideally, no part of the towel that touched your hand touches the plate. Gloves may help, but then you also have to cognizant of your gloving technique (never touching the outer contact surface of glove while putting on glove)

Have you recently lubricated the Bondtech gears and gotten lithium grease into the filament groove?

Did you touch the filament with oily fingers?