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Multiple Problems - One Solution  

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rmm200
(@rmm200)
Noble Member
RE: Multiple Problems - One Solution

I personally would not use dishwasher detergent on a print sheet. That stuff is caustic!

Dawn is both gentle and recommended.

Posted : 29/07/2019 4:20 pm
ben.g16
(@ben-g16)
Estimable Member
Topic starter answered:
RE: Multiple Problems - One Solution

Went to the store and bought a bottle of Dawn (Blue = dishwashing).  Thoroughly washed one side of sheet.  Paper towels all the way.

Began print. Gross failure to stick.  See photo.  Then I plastered the sheet with Suave hairspray to a wet surface.  I let it dry completely and repeated the print. The print stuck much better, but not good.  See second picture.  I don’t understand the wavy part in the fill.

 

(Note, files are backwards - havent been able to get them to load correctly)

 

 

 

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This post was modified 5 years ago 3 times by ben.g16
Posted : 29/07/2019 7:48 pm
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(@)
Illustrious Member
RE: Multiple Problems - One Solution

If you have to add anything to the sheet, it is dirty.   But -please verify you are using a Prusa branded PEI sheet; not an aftermarket copy.  Your images look like you have a clone, not a Prusa original sheet.

New Prusa sheets are very unlikely to have oxidation, but in the realm of far fetched universes, it could happen.

Oxidation can be removed by scrubbing the bed vigorously with a paper towel dampened with acetone. Use gloves to protect your hands and the bed. You don't want the chemicals washing body oils off your fingers and depositing them on to the bed.  Scrub the bed several times, using several new pieces of paper towel each time (I cut towels into 2x4 inch pieces to scrub with).  You will see a white film develop. Then, take the bed to the kitchen sink, a drop or two of detergent is all that is needed, wash until the residue is gone and then rinse until water beads on the surface of the sheet.  If the water is sheeting (wetting the surface), the bed is not clean.  When clean, there won't be a lot of water left to dry because most will have beaded off. 

If scrubbing like this doesn't help - then you have a bad sheet. Contact Prusa via chat and have them swap your sheet for a replacement.

 

ps: a Prusa smooth PEI sheet has a grid and a lot of warnings on it: I see none of these features on the sheet you are using. Makes me wonder if Prusa has a new source and this new source is having problems...

 

This post was modified 5 years ago by --
Posted : 29/07/2019 9:04 pm
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(@)
Illustrious Member
RE: Multiple Problems - One Solution
Posted by: rmm200

I personally would not use dishwasher detergent on a print sheet. That stuff is caustic!

Dawn is both gentle and recommended.

He said dishwashing not dishwasher ...

 

Posted : 29/07/2019 9:06 pm
ben.g16
(@ben-g16)
Estimable Member
Topic starter answered:
RE: Multiple Problems - One Solution

The metal sheet came from Prusa with the MK3 kit a year ago.  Will try the acetone/soap routine and report.

Posted : 29/07/2019 11:44 pm
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(@)
Illustrious Member
RE: Multiple Problems - One Solution

Ah -- I missed the TWO YEARS OLD printer part. lol.  Yes, the sheet may very well have oxidized and built up a lot of crud over the years.   I just finished up a rash of PLA then PETG parts and the PETG temps baked on some PLA residue soap and water couldn't deal with.   After several scrubs with acetone, the sheet started to behave again. 

As an alternative: BobStro says he has good luck using a very fine ScotchBrite pad to remove oxidation. Think 4000 grit polishing compound though, not sandpaper.   https://forum.prusa3d.com/forum/profile/bobstro/   I can't recommend any grit containing products... but Bob has used this method long enough I'd trust his opinion.

He maintains a web site of info - read on for his ScotchBrite info. http://projects.ttlexceeded.com/3dprinting_bed_cleaning.html

 

This post was modified 5 years ago by --
Posted : 30/07/2019 12:42 am
ben.g16
(@ben-g16)
Estimable Member
Topic starter answered:
RE: Multiple Problems - One Solution

ONE year old.  Dont have any grit residue.  Remember, I have only printed about 4 spools. this project has been R&D, not production.

Just finished the acetone wash down (4x) with nitrile gloves.  No white residue.  See pic.

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Then did soap bath (4x). Maybe some beading, but not everywhere.  Getting ready for a print test now.
This post was modified 5 years ago by ben.g16
Posted : 30/07/2019 1:08 am
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(@)
Illustrious Member
RE: Multiple Problems - One Solution

Ben, if you're not getting fair adhesion after this, you may want to try a different filament.   Other than that, there really isn't much more I can suggest. 

 

I printed with the sparkly filament that gave the most trouble - not sticking, spaghetti print half way up, jambing. 

Rereading your original post, you mention sparkly filament: filaments with flakes in them  are notorious for plugging 0.4 mm nozzles.  Most brands suggest 0.8 mm nozzles for filled glitter filaments.  Using that type of filament with a 0.4 mm nozzle would explain your jams and inconsistent print issues mentioned.  

 

Posted : 30/07/2019 1:44 am
ben.g16
(@ben-g16)
Estimable Member
Topic starter answered:
RE: Multiple Problems - One Solution

Result:  The boundaries printed well at startup, but the fill is still poor.  The picture shows the ragged peaks in the fill.  I held a flashlight to the side to enhance contrast.

This post was modified 5 years ago by ben.g16
Posted : 30/07/2019 1:44 am
Dave Avery
(@dave-avery)
Honorable Member
RE: Multiple Problems - One Solution

still looks like poor adhesion or moist filament. about the only cause of bubbling in the first layer is oil/moisture on the bed boiling off under the filament or moisture in the filament boiling while extruding. one test for moist filament is to raise the extruder so you can watch the nozzle and extrude manually  and watch to see of the filament is extruding smoothly and the is no vapor coming out with the filament. the filament should be is clean smooth thread with a uniform diameter 

Posted : 30/07/2019 2:13 am
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(@)
Illustrious Member
RE: Multiple Problems - One Solution

Here's what bad filament looks like: note non-uniform diameters.

Posted : 30/07/2019 3:30 am
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(@)
Illustrious Member
RE: Multiple Problems - One Solution

Actually - that latest image looks like you are getting good adhesion, but layer one is going down a bit thick.  Either the extrusion factor is high, or the nozzle is set a bit on the low side, or both.  But the ridges between tracks is a common "nozzle too low" outcome.  The mountainous peaks, they fit to low nozzle problem, too, but also might be incorrect extrusion multiplier or filament diameter.  Basic "too much plastic flowing" ...

 

One of my test prints showing my nozzle too low.

This post was modified 5 years ago by --
Posted : 30/07/2019 3:38 am
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(@)
Illustrious Member
RE: Multiple Problems - One Solution

Up side is it looks like you have one problem solved .. now to the easier ones.

Posted : 30/07/2019 3:41 am
tom.s33
(@tom-s33)
Eminent Member
RE: Multiple Problems - One Solution

ben.g16, it might be good to let us know what your print settings are for a known starting point: (unless it's felt we're beyond this now)

1. Brand / type of filament

2. Heat bed temp

3. Nozzle temp

4. Print speed

5. Belt tightness

6. Live Z setting (different for each of us, but it might help)

7. Have you tried printing on both sides of the sheet?

This post was modified 5 years ago 3 times by tom.s33
Posted : 30/07/2019 6:03 am
ben.g16
(@ben-g16)
Estimable Member
Topic starter answered:
RE: Multiple Problems - One Solution

Tim was right about the Z layer.  I changed filament and started a print with the same rough surface.  Then I began a live Z calib and raised the nozzle from -.700 to -.625.  The surface smoothed out and became uniform.  I missed getting a first layer pic.

The rest of the settings are 

1. 0.2mm layer height, "mid quality” speed settings, standard PLA temps

2.  35º PINDA setting,  7x7 mesh

Summary:

Extensive cleaning seems to have solved the adhesion problem.

Setting first layer height seems to have solved the alligatior skin first layer.

Thanks to all who helped troubleshoot.

Will report if anything goes wrong.

Posted : 30/07/2019 2:22 pm
-- and Dave Avery liked
ben.g16
(@ben-g16)
Estimable Member
Topic starter answered:
RE: Multiple Problems - One Solution

After all the hassle and good advice, I finally found the culprit.  It was the brand new filament.  Let me explain.  I used the advice offered above for the following procedure.

1. Thoroughly wash the sheet with soap and water.

2. Set the active Z height.  I did this by creating 12] 20x20mm squares one layer thick (0.2mm).

3. With the clean bed I printed the 12 squares, adjusting the Z height from -0.620mm to -0.730mm as it jumped between squares.  See the pics.

4. The adhesion of the squares varied in somewhat random fashion over the thicknesses except on the thickest row.  I stripped the squares and looked at the bottoms for the most uniform fill pattern.  The best ones were -0.660 & -.0670mm.

5. Then I changed the filament to an old scrap piece I had and printed the squares again at the varying thicknesses. All printed perfectly (forgot to take a pic). The best ones were again -0.660 & -.0670mm.

6. I returned the filament to Amazon and bought the kind in the second test.

7. Three conclusions:  

        Watch out for quality control on the filament.  It was the PLA + type, spec’d at +/-0.02mm, but it must have been contaminated.

        Clean the bed thoroughly with soap and water as a base line for trouble shooting.       

        Run a good Z calibration test with multiple sample heights to find the best one.

Epilog:  The replacement filament has worked very well for about ⅓ of the roll.  I am cleaning with an isopropyl alcohol / paper towel wipe between each run.  When it starts to lift, I do a thorough S&W cleaning.

       

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This post was modified 5 years ago 3 times by ben.g16
Posted : 09/08/2019 8:58 pm
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