Bed Adhesion Issues  

RE: Bed Adhesion Issues

Scrub the bed with a non-acratch sponge and dish soap.  Then rinse well and dry it off.  

RE: Bed Adhesion Issues

Posted by: @dustin-1

I’ve had my mk3s for about a month now, probably made 10-12 prints.  I cleaned the print bed today with 95% alcohol cause I was having adhesion issues, I thought it would help but it hasn’t. I tried decreasing the speed to 75% and it’s still an issue. 

any tips?

Hello and welcome to the Prusaforum!

Besides an absolutely clean and grease-free printing plate, the setting of the Z-firstlayer is also very important:

https://help.prusa3d.com/en/article/first-layer-calibration_112364

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

RE: Bed Adhesion Issues

Clean bed with dish soap.

First layer must be 100%.

Both settings above are for best sticking to the bed, and that 3d printing is possible.

It also helps against the big ball of filament sticking to the extruder.

RE: Bed Adhesion Issues

I am also having this issue, does someone have any solution for this? kindly share your views DQFanSurvey, thanks in advance.

RE: Bed Adhesion Issues

a lot of help here, pretty sure I resolved it now.

A new issue I'm having though is the print head dragging across the print, ever so slightly, I noticed the z-lift is set at 0.6mm.  Is that the correct place to adjust and should it be more?

RE: Bed Adhesion Issues

@dustin-1

More info?

Could be the print is coming loose.

Print can warp?

Print can be stringing, and filament can stick higher then the model.

Check if all bolts on the printer are not loose. Check if extruder not loose(a little it should be loose).

RE: Bed Adhesion Issues

I wouldn't increase the z-lift any higher than the default 0.6mm.  If your print head is dragging across the print, it might mean you are over extruding.  What does your print quality look like?  Can you share some pics?

RE: Bed Adhesion Issues

I just ordered the I3 MK3S. I'm reviewing articles/videos to get a head start in knowledge before it arrives. For build surface cleaning, Josef recommends 90% or better IPA to clean the PEI surface ( ). Many of the comments in the forums recommend against using IPA and using soap instead. What am I missing?

RE: Bed Adhesion Issues

@timbratten

Your missing nothing.

If you print for a longer time, you will notice that prints start not sticking anymore.

Then cleaning with dish soap is a lot better.

If you print parts that have a small footprint to the bed you notice difference in cleaning.

Also with big flat models that warp.

Alcohol does not clean off everything. dish soap does.

RE: Bed Adhesion Issues

@peter-m26

!00% true and especially true with months of finger grease.  

RE: Bed Adhesion Issues

Alcohol works - but only if you have an industrial supplier like Prusa does. They buy it in 50 gallon drums. A few gallons of hot water along with a few drops of good dish detergent dissolves dirt and oils far better than a gram or three of alcohol. It is all about volume and dilution. 

The bad side of alcohol is that if not done with adequate volume it will leave a microscopic layer of oil, one you can't see and is very good at preventing PLA from sticking to the PEI.

Here's an example of a bed freshly cleaned with 99% alcohol, cleaned very well two or three times, and I used lots of alcohol, too. As you can see, layers still pulled right off.

RE: Bed Adhesion Issues

@tim-m30

I hate to disagree but I used military and hospital grade that is over 99%.  There is nothing magical about IPA from those sources. It does not work any better than the stuff I buy locally.  

RE: Bed Adhesion Issues

Posted by: @charles-h13

@tim-m30

I hate to disagree but I used military and hospital grade that is over 99%.  There is nothing magical about IPA from those sources. It does not work any better than the stuff I buy locally.  

I've had good luck with drug store brand 91% IPA, but it's impossible to find lately.  I can get 99% 'technical grade' IPA easily, so that's what I've been using.

I also use denatured alcohol occasionally, which seems to cut glue stick residue a bit better.

RE: Bed Adhesion Issues

Posted by: @charles-h13

@tim-m30

I hate to disagree but I used military and hospital grade that is over 99%.  There is nothing magical about IPA from those sources. It does not work any better than the stuff I buy locally.  

What part of the words I used didn't make sense? I said nothing about grade of alcohol. 

As for a claim that you have access to alcohol at over 99%? Wow. What happens when you open up the cap of a bottle of that stuff in a room with normal air?  But that's a different topic.

Most people do not use a quart of alcohol, let alone gallons to clean their print sheet. So by volume, water with detergent at a sink dilutes the oils much better than alcohol can.  The math is simple: a gallon of detergent-water versus an ounce of ANY dilution of alcohol combined with 10 mg of oil and dirt: which one will clean better? Now, who uses a full ounce of alcohol to clean their print sheet? 

As for cleaning off glue stick: water is best. After all, most of the glue sticks we use are WATER SOLUABLE. And alcohol generally does not dissolve it - but the water that has been absorbed into the alcohol does a fair job. So it's that 30% water share of your denatured alcohol that is doing all the work (and all denatured means is they added a poison so the alcohol isn't drinkable).

https://en.wikipedia.org/wiki/Denatured_alcohol

Denatured alcohol is ethanol (ethyl alcohol) made unfit for human consumption by adding one or more chemicals (denaturants) to it.

RE: Bed Adhesion Issues

@tim-m30

I suspect you must work at Prusa since you know so much about there sheet cleaning.  

The bottom line is 99% is available on the internet.  That is where I buy it.  It will not clean off all dirt or grime.  I often have to use water and soap.

No one I know uses denatured ethyl alcohol.  I recommend you use Isopropyl Alcohol or soap and water.  

RE: Bed Adhesion Issues

@jsw

Me too.  99% is readily available.  

RE: Bed Adhesion Issues

I started using the denatured alcohol because I had it and I could not find 91%IPA during the height of the pandemic.

It's a common solvent and very good degreaser.

Now, the bottom line here is that we're probably going to have to agree to disagree whether water-based solvents or organic solvents are better for cleaning print sheets.

I really believe that it's not so much what you use to clean it, than the fact that the sheet is Really Most Sincerely Clean (tm) and free of any crud, fingerprints, etc.

RE: Bed Adhesion Issues

@jsw

No issue.  I have been print for years.  It is just my experience that sometimes you have to use soap, water, and some elbow grease.  

RE: Bed Adhesion Issues

Posted by: @timbratten

[...] Many of the comments in the forums recommend against using IPA and using soap instead. What am I missing?

Prusa changed their official instructions after the release of the textured sheet. Prior to the change, a wash with Dawn, occasional wipe with acetone and regular wipes with isopropyl alcohol were Prusa's recommendations. 

The textured sheet has a mixed reputation. If you got a good one, alcohol may be all you need. If you get a bad one, it may be insufficient. That's why some of us still preach the old ways. If your sheet won't adhere, you have nothing to lose by trying other measures. There is no warranty on them even if defective from the factory. (So far as I know, this won't stand up in the EU, but I'm not in a position to test the consumer protection  laws there.) Prusa also changed the smooth sheet guidance, although old YouTube videos are still around with JP himself describing the old ways. I think they did this because their steel sheets tend to corrode easily. Needless to say, I'm unhappy with Prusa's CYA response.

In my experience, care and feeding of the sheets (Prusa and other smooth PEI, 3rd party textured) are the same. Here’s an unscientific breakdown.

1. Isopropyl alcohol and acetone work as solvents , breaking apart grease molecules. These solvents do not completely dissolve grease, but do break it down far enough that it can be removed from surfaces easily.

2. The more concentrated the solvent, the more effective it will be at a given volume. Those little 70% isopropyl wipes do work… on a shiny new PEI sheet. They’re just not effective dealing with larger amounts of accumulated grease. This is why 91%+ alcohol is recommended.

3. Acetone is even more effective, breaking up oxidation on the PEI surface, but can make the PEI surface brittle and prone to cracking if over-used.

4. The amount of grease that any solvent will effectively break down is directly proportional to the volume of solvent to grease. The more you apply, the more grease it can effectively break down. The more concentrated the solvent, the more grease a given quantity can break down.

5. Alcohol, acetone and any other solution you apply directly to the bed is just going to move those broken-down grease and grime molecules around. Some will be picked up by wiping with a clean towel, but some will remain on the PEI sheet.

6. A dunk under the sink with Dawn dish soap is the most effective method of cleaning. Dish soap is a surfactant , not a solvent. It works in a fundamentally different way, bonding both grease and water molecules to wash away contaminants.The reason this is so effective is not because Dawn is “stronger”, but because there’s simply a much greater volume of Dawn and water and the grease is washed away from the PEI sheet.

7. Windex, a wipe of finger grease, talcum powder or specialized release agents can be used to reduce adhesion when using hot, sticky materials that grip the PEI surface too firmly such as PETG. It is still a good idea to clean the PEI before a print to get an even surface, even if you will be applying a release agent for pritning with sticky materials.

8. If you are printing high-temperature materials (e.g. PETG at 260C on a 90C bed), test to make sure it will release once cool without damaging the PEI surface. You may want to use glue stick or other release agents for these materials. Test on a sacrificial PEI surface if possible. 

More notes here.