PLA not sticking???  

Re: PLA not sticking???

I had my Prusa i3 mk3 since one week and i had the same problem.
On my other printer i print on glass with 3DLac, witch works perfect.
Now i try 3DLac on the PEI sheet and it works perfect for me.
Normaly i print 10 to 20 peaces until i clean the glass.
3DLac is easy to clean. Just warm water and soap.

Re: PLA not sticking???

Assuming that live z was not changed and printer was not moved, then this points to bed cleaning. Have you tried cleaning the bed with warm water and dish washer soap? Acetone is another option too. Then apply 99% alcohol.

Stringy filament is another issue I think. I noticed my filament pla suddenly started to ooze like crazy after using half of the spool. Same settings and same print. Almost sure that my case is moister. It also leaks from the nozzle more than before. Maybe this is your case too.

Re: PLA not sticking???

Maybe it is moisture? I have a camera with a temperature sensor in my printer area and it has been going off as humid in there 50% humidity. I clean the bed plate after every use with alcohol so its clean, never used acetone on it yet. I will continue to troubleshoot and maybe can figure this out.

Re: PLA not sticking???

Moved the printer to a better room and still same problems, could it be I need a new nozzle?

Re: PLA not sticking???

The on-board Z calibration is tough. From your pic, it's clear you've got a calibration issue.

When you print that gcode file, it will make some obnoxious beeps, then start printing a 75x75mm single layer of filament. Let it run for a bit, then start adjusting your Live-Z setting until you get a good pattern.

When you get a good pattern, you should be able to rub over the filament without dislodging it. Gradually move the nozzle down (more negative numbers) until it starts sticking. Start near 0, then you can use larger (e.g. 0.100) increments until it starts sticking. Once it's sticking consistently, continue slowly adjusting it downwards (more negative values) until the filament is squished. If the pattern starts distorting or tearing, you're too close. Back up slowly.

Repeat as necessary.

Re: PLA not sticking???

It was printing perfect then all of a sudden came the no sticking. Maybe it is a bed issue but I always clean it with alcohol between prints. Maybe I need acetone but the bed looks clean. I will start at 0 and try that as you suggest but I do not know why my first layers all of a sudden would get bad.

Re: PLA not sticking???

I tried to re calibrate it and live Z and still massive stringing/not sticking. After examining it,the filament is not coming out evenly so a bad or blocked extruder? I did a pull cold and hot pulls and still same results. Maybe replace nozzle? Any ideas I would appreciate, printer has been off line now for 2 weeks 🙁

Re: PLA not sticking???

[...] After examining it, the filament is not coming out evenly so a bad or blocked extruder? I did a pull cold and hot pulls and still same results. Maybe replace nozzle? I'd start with another nozzle, just to eliminate it from consideration. If that's not right, it's impossible to get everything to work correctly.

Did you try using the gcode files from the Life Z Adjust thread? Using those is much easier than the on-board live-z routine. Again, until the layers stick with a gentle rub, it's not right. You might try making some larger adjustments downwards (more negative).

Re: PLA not sticking???

Here is the best I could get it dialed in. The second layer flux is my original Z that I used for months. As you can see the the "stringing" is not good.
I was going to order a nozzle and some pei sheets from prusa but $40 shipping to the US seems high for items that cost $30.

Re: PLA not sticking???

Here is the best I could get it dialed in. The second layer flux is my original Z that I used for months. As you can see the the "stringing" is not good.It's hard to see from that picture, but it looks like it starts out poorly. The stringing is largely from the outline skirt that has drifted into the print. It seems to shift to better, although it's obviously printing over the loose skirt material. I'd try the same print again with the newer setting you selected in the top part (after giving the bed a good wipe with IPA). Try for a bit better focus on the pics if you can. It's hard to see the top part clearly.
I was going to order a nozzle and some pei sheets from prusa but $40 shipping to the US seems high for items that cost $30.
I wouldn't bother with a new sheet just yet. If your problem is not your sheet, you'll have possibly ripped up a perfectly good one for no reason. You might have one bum side, but having 2 is unlikely.

Prusa has to ship from overseas, so their options are limited. I've become spoiled by Amazon's 2 day service. I was surprised when I ordered filament and nozzles from Matterhackers (matterhackers.com) and they arrived in 2 days. A new nozzle was roughly $8, although I went for a hardened steel extra for another $22 or so.

Re: PLA not sticking???

I've had the same issue 3 days of good prints & fun.(best toy ever) then started stringing and peeling. More strange was the printer just finished the 150um frog fine. I'm using PLA, Clear bed, straight into next frog and BOOM.
Tried cleaning bed, brand new pla out the box. Wish I had another build plate to try

Re: PLA not sticking???

I talked to support and they suggested a ptfe tube change...... I disassembled it and changed the tube... (note the tube looked fine). I guess ill reassemble it and give it a go, I do not think that was the issue

Re: PLA not sticking???

Went through a ton of troubleshooting and it appears one of the wires connecting the pin was broke. Support was awesome but the situation is frustrating.... I guess that's a reason to have 2 printers.

Re: PLA not sticking???

I use 3DLac. Works perfectly.

You can try somting like
3D Lac
Dimafix
Haarspray

Re: PLA not sticking???

travis.c5 could you explain a little bit more? I don't quite understand your post. I'll be interested to know if you found a solution so i can check for the same.
I'm getting very frustrated with the fact I went from a perfect print 😀 , clean the bed, straight into the next print to have this stringing and sticking issue for 2 days and counting. 😡

Re: PLA not sticking???

Hi everybody,

I've the same problem like ian.c19. That is strange because i start printing with PLA on the assembled kit from perfest prints. after few weeks PEI sticking problems started - first sometimes , now generally 🙁 .

I checked calibration XYZ few times, first layer calibration and Live Z test. At first look like cold bed surface or too cold plastic. Extruded plastic is rolled and do not stick to PEI.

After first problems with sticking i increase temperature of bed and nozzle - it help 😀 for 2 or 3 prints only 🙁 - in this moment 230 degree of nozzle and 70 degree of bed does not help.

PEI from beginin was cleaned from time to time by universal solvent i do not use acetone. After few weeks i bought IPA99. Now i'm after tests with solvent, acetone, ipa - doesn't help.

last print 180x180mm have nice (not perfect) surface but you can see some streaks like as after wiping with a rag. it is possible to look only when surface is big enough :geek: .

I check nozzle too, after change and calibration, problem is the same.

What i noticed additionaly:

1. Problem startup after about 0.5kg filament usage - but after change to new one (vacum packed) will be beter only first print - in my opinion accident
2. as i remember first problems was after few times of using IPA99 in place of universal solvent (i try to back to solvent - without success) - in my opinion without matter
3. additional heating +5 degree to base one help one - two times, next temperature increase do not help - i checked temperatures monitoring and heating - looks good and working same like at the begining
4. little bit more plastic is going out of the nozzle when nozzle is heated
5. more plastic string on the free runs are - probaby after increase of nozzle temperature
6. PEI surface is clean and smoth (with some skratches after colision) after week of usage first bubble under the PEI i seen but in this moment they dissapear - probably wrong print removing 😕 .

Please 😥 - all sugestions will be helpfull - i will try all what i will find here and in the internet but i have less and less ideas.

Re: PLA not sticking???

travis.c5 could you explain a little bit more?

Re: PLA not sticking???

Did anyone of you already try to clean the bed with dish washing liquid?
Isopropyl and Acetone do not remove all kinds of grease and fat.
Give it a good wash, and don´t touch the Bed with your fingers and/or hands.
That should solve your adhesion problem.
As long as your z-calibration is ok.

Re: PLA not sticking???

Ok sorry for the delay updating:

I tried changing the tube and it did not work. I changed out the heat cartridge and installed a new nozzle. Same problem! Prusa said I needed a new hot-end so they were kind enough to send me a full assembled hot-end. I am still getting the stringing and pla not sticking to bed. I wash the bed before every print with isopropyl alcohol. I have much more troubleshooting to perform so I will keep this thread updated when I find a solution.
Steps I have taken so far:

Change complete hotend out
Tried 2-3 different brands of filament

*I am working on the first layer calibration and probably will change the pei sheet out on the bed even though it looks just fine.... If anyone has any ideas that I can troubleshoot I am all ears