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First layer test looks okay, but can't print Benchy  

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jim.w15
(@jim-w15)
Active Member
First layer test looks okay, but can't print Benchy

My first layer test print looks okay to me. I still feel like I have no idea what I'm looking at and whether it looks the way it should, but the corners are square, the lines are straight, the box at end of first print looks okay.

When I print Benchy, the first lines don't stick and the extruder drags around the PLA until it comes out like mashed potatoes and covers the extruder. This is on the first minute of printing Benchy, so I pause->stop, raise Z axis, clean extruder, clean bed, try again and fail again.

I've tried using the glue stick on the bed, but same thing, it doesn't stick and the extruder drags around the printed plastic until I stop the print. I have no idea what I'm doing and I feel like I'm ready to throw the entire thing out the window at this point.

Reddit forum has suggested glue stick, cleaning bed, painter's tape (haven't tried that yet), redoing first layer test, etc. Someone mentioned there's a live chat here, but I can't find that either.

update - also when I print the Prusa.gcode file (I think it's a rectangle), it looked okay for about 1/3 (lines were spaced a bit) but about half way through, the extruder and object got stuck together and it just slid it around and became a garbled mess (same as with benchy). I had applied the glue from provided gluestick all over the area, but it still didn't stick to surface (even the initial outline didn't stick within fractions of seconds of being applied).

Posted : 04/01/2019 10:18 pm
bobstro
(@bobstro)
Illustrious Member
Re: First layer test looks okay, but can't print Benchy

If you're not confident in your 1st layer, your Live-Z is the place to start. Try using the "life adjust" method for calibrating Live-Z. It's much easier to use and understand than the on-board Live-Z routine.

Ignore any advice from anyone not using a Prusa printer. The PEI flex steel sheet does not require hairspray, glue or any of the other solutions lesser print bed solutions require. It does require a very clean PEI surface. If you've handled it a lot, take it to the kitchen sink and give it a good wash with Dawn dish soap. Dry it with a clean paper towel and avoid touching it at all costs.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 04/01/2019 10:44 pm
gnat
 gnat
(@gnat)
Noble Member
Re: First layer test looks okay, but can't print Benchy

1) Give your PEI sheet a good wash in the sink with dish soap that does not contain anything "for your hands".
2) Using lint free towels to hold it (don't touch more than the edges with your fingers) put it back on the bed.
3) Pour some 90%+ IPA on it and wipe it down really well with a lint free paper towel (again, do not directly touch the sheet).
4) Repeat with acetone.
5) Pre-heat and print
6) Avoid touching the PEI surface at all costs. (if you do, just simply repeat all this)

My Benchies got much farther (like within 10 layers of completing!), but had the same problem you describe. After doing the above I have not had another print failure. I followed the same routine 4 or 5 times, but now I'm down to just the alcohol wipe down between most prints and have still had no issues.

As bobstro said, don't listen to anyone that says you need to put something on the PEI sheet for standard PLA.

MMU tips and troubleshooting
Posted : 04/01/2019 11:01 pm
jim.w15
(@jim-w15)
Active Member
Topic starter answered:
Re: First layer test looks okay, but can't print Benchy


If you're not confident in your 1st layer, your Live-Z is the place to start. Try using the "life adjust" method for calibrating Live-Z. It's much easier to use and understand than the on-board Live-Z routine.

Ignore any advice from anyone not using a Prusa printer. The PEI flex steel sheet does not require hairspray, glue or any of the other solutions lesser print bed solutions require. It does require a very clean PEI surface. If you've handled it a lot, take it to the kitchen sink and give it a good wash with Dawn dish soap. Dry it with a clean paper towel and avoid touching it at all costs.

My kit came with a glue stick. I assume that's what the Prusa glue stick is for? Or did I miss an assembly step somewhere?

I tried the Life Adjust Z and the first line that's always drawn in the top of the bed looked fine, then

LAZ 1 - complete extruder blob, nothing stuck except to the extruder, so I stopped it

LAZ 2 - first square outline was okay. 2nd inner square outline didn't stick, then got caught by extruder, made a blob on bed, then everything started getting stuck/blobs, etc. so I stopped it

First layer test still looks fine to me.

Posted : 04/01/2019 11:06 pm
jim.w15
(@jim-w15)
Active Member
Topic starter answered:
Re: First layer test looks okay, but can't print Benchy


1) Give your PEI sheet a good wash in the sink with dish soap that does not contain anything "for your hands".
2) Using lint free towels to hold it (don't touch more than the edges with your fingers) put it back on the bed.
3) Pour some 90%+ IPA on it and wipe it down really well with a lint free paper towel (again, do not directly touch the sheet).
4) Repeat with acetone.
5) Pre-heat and print
6) Avoid touching the PEI surface at all costs. (if you do, just simply repeat all this)

My Benchies got much farther (like within 10 layers of completing!), but had the same problem you describe. After doing the above I have not had another print failure. I followed the same routine 4 or 5 times, but now I'm down to just the alcohol wipe down between most prints and have still had no issues.

As bobstro said, don't listen to anyone that says you need to put something on the PEI sheet for standard PLA.

I've cleaned my PEI sheet a hundred times today with dish soap and Windex as suggested by Joe Prusa in video. I'll go to store and buy some rubbing alcohol. I have no idea where to get acetone or what it is.

Posted : 04/01/2019 11:08 pm
bobstro
(@bobstro)
Illustrious Member
Re: First layer test looks okay, but can't print Benchy


[...] I've cleaned my PEI sheet a hundred times today with dish soap and Windex as suggested by Joe Prusa in video. I'll go to store and buy some rubbing alcohol. I have no idea where to get acetone or what it is.
Windex and glue stick are recommended if you're printing materials that stick aggressively to PEI such as PETG. They are used because they reduce adhesion compared to isopropyl alcohol or acetone. For PLA printing, you normally should clean using these solutions in this order:

  • Regularly between prints use 91%+ isopropyl alcohol (IPA)

  • When alcohol is insufficient, use 100% acetone

  • When acetone fails, or if you've made a mess of your bed, dunk it under the kitchen sink with Dawn dish soap
  • At all times, avoid touching the sheet. If you do touch it, be prepared to clean it again.

    You are already at step 3 if you've been trying glue or anything similar. Don't blast all of them at once. Try washing the sheet under the sink with Dawn dish soap and avoid touching it. Then do your Live-Z calibration.

    You can find acetone at a drug store, usually as fingernail polish remover but be sure to only get 100% acetone. Also use 91%+ isopropyl alcohol.

    My notes and disclaimers on 3D printing

    and miscellaneous other tech projects
    He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

    Posted : 04/01/2019 11:46 pm
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy



    [...] I've cleaned my PEI sheet a hundred times today with dish soap and Windex as suggested by Joe Prusa in video. I'll go to store and buy some rubbing alcohol. I have no idea where to get acetone or what it is.
    Windex and glue stick are recommended if you're printing materials that stick aggressively to PEI such as PETG. They are used because they reduce adhesion compared to isopropyl alcohol or acetone. For PLA printing, you normally should clean using these solutions in this order:

  • Regularly between prints use 91%+ isopropyl alcohol (IPA)

  • When alcohol is insufficient, use 100% acetone

  • When acetone fails, or if you've made a mess of your bed, dunk it under the kitchen sink with Dawn dish soap
  • At all times, avoid touching the sheet. If you do touch it, be prepared to clean it again.

    You are already at step 3 if you've been trying glue or anything similar. Don't blast all of them at once. Try washing the sheet under the sink with Dawn dish soap and avoid touching it. Then do your Live-Z calibration.

    You can find acetone at a drug store, usually as fingernail polish remover but be sure to only get 100% acetone. Also use 91%+ isopropyl alcohol.

    Went to store. Bought 91% rubbing alcohol and dawn dish soap (no fragrances, nothing except just plain soap). Rinsed and lathered and soft sponged bed in sink. Dried. Wiped with rubbing alcohol. Still looks spotless.

    Tried the squarebox "life adjust z" file from previous thread. IMHO, it was worse than before. Even the first square (first 4 lines) didn't stick, after a couple seconds the entire square was being dragged around and then a blob appeared. Cleaned bed again with rubbing alcohol. Repeated. Same thing didn't make it past the initial outline square before everything came off bed and blob started to form. Cleaned bed again with rubbing alcohol.

    update - just tried the first layer print after cleaning it again and I couldn't even get to the square at end of test before everything came loose and blob started to form around extruder.

    Posted : 05/01/2019 12:10 am
    Bunny Science
    (@bunny-science)
    Noble Member
    Re: First layer test looks okay, but can't print Benchy

    If the sheet is clean and you're not getting good adhesion, there are three things I would check...

    1. Is the PINDA loose? Carefully check the screw isn't loose.

    2. Is live-Z low enough? Those test patches should be coming out as a single fused sheet when Z is down far enough. If they are still composed of individually separable strings, Z isn't low enough.

    3. Is the filament spool "wet" It's possible the spool needs to be dried.

    Posted : 05/01/2019 12:17 am
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy


    If the sheet is clean and you're not getting good adhesion, there are three things I would check...

    1. Is the PINDA loose? Carefully check the screw isn't loose.

    2. Is live-Z low enough? Those test patches should be coming out as a single fused sheet when Z is down far enough. If they are still composed of individually separable strings, Z isn't low enough.

    3. Is the filament spool "wet" It's possible the spool needs to be dried.

    1. Not loose.

    2. First layer printed (had before these cleanings) worked fine and looked good at -0.650. Tried to do first layer again and failed to stick all 4 attempts on first layer. When using gluestick, at least first layer worked on previous attempts. Can't even make it to the square now with clean bed.

    3. Not wet. Just opened it today from the bag it was shipped in. There's no moisture in the air/house.

    Posted : 05/01/2019 12:41 am
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy

    Ok. Now, I can't even get the first layer test to print. I can live adjust the Z value during the first layer test, but regardless of the Z value, the square doesn't stick and it turns into a blob when doing this on a clean, rubbing alcohol wiped, bed. I've failed this first layer test about 7 times so far since cleaning the bed.

    Posted : 05/01/2019 12:55 am
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy

    Update. Went through first layer test a few more times, brought the Z way down to starting value and everything worked. Slowly started increasing Z value until after 4-5 first layer prints, I got it back to -0.65.

    Got excited, started Benchy, then on the very first line segment it spurted a blob and ended short, then x axis and y axis and extruder and everything went haywire and started stopping/starting/stopping/starting like stepping then hitting something then stepping again. So I factor reset everything and I'm starting over again.

    Posted : 05/01/2019 1:54 am
    gnat
     gnat
    (@gnat)
    Noble Member
    Re: First layer test looks okay, but can't print Benchy

    Did you clean it with acetone yet? Given what you tried before starting this thread I'd bet on it needing a good acetone cleaning to refresh the PEI and help clean of residual gunk.

    MMU tips and troubleshooting
    Posted : 05/01/2019 3:10 am
    gnat
     gnat
    (@gnat)
    Noble Member
    Re: First layer test looks okay, but can't print Benchy

    Another option, have you tried both sides of the plate? If you haven't done the same things to the other side, flip the plate, give it a good cleaning, and try that side to see if you get different results.

    MMU tips and troubleshooting
    Posted : 05/01/2019 3:12 am
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy

    Thanks. After the reset, I can't get past the XYZ Calibration step. Keeps failing on the first location. So I'm now worse than before.

    Posted : 05/01/2019 7:00 pm
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy

    Another update. The XYZ Calibration via the Wizard failed about 10 times. Then I tried running it via Calibration->XYZ Calibration menu and it worked first try. First Layer Test went well and tuned it to -0.625 (yesterday, ended at -0.65).

    However, on my first multi-layer file, the prusa.gcode file, everything was going great and I had thought it would be successful. It printed all of the base layers, but after a bit, one side started coming off the bed, then when it started on the first lettering layer, it started sliding the entire rectangle around.

    Posted : 05/01/2019 8:43 pm
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy

    Went for dog walk, came back and printed Prusa.gcode again.

    This time, based on reddit suggestion, I preheated the bed to 70F instead of default 60F. Logo stuck to clean surface for about 10 minutes then 1 corner started to become unstuck. I let print finish and by time it was iver the final print looked okay. The corner slowly started pulling that corner higher from surface, but only came off just enough for nozzle to not hit it. It was pushing down on the print when printing over that corner (the "P").

    I'm going to make another trip to the store for acetone in a few minutes and then clean it with that and do another print.

    Posted : 05/01/2019 10:14 pm
    Bunny Science
    (@bunny-science)
    Noble Member
    Re: First layer test looks okay, but can't print Benchy

    The XYZ Calibration via the Wizard failed about 10 times

    There is something awry with the build, if you're having that tough a time passing XYZ calibration. I'm concerned about belt tensions, bearings, and rod alignments, obstructing wire routing, loose Z top mounts. I think we should identify and fix those issues so they don't mess up your prints in mysterious ways.

    What were the failure messages?

    What does your Support/belt status read for slackness?

    Posted : 05/01/2019 10:47 pm
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy


    The XYZ Calibration via the Wizard failed about 10 times

    There is something awry with the build, if you're having that tough a time passing XYZ calibration. I'm concerned about belt tensions, bearings, and rod alignments, obstructing wire routing, loose Z top mounts. I think we should identify and fix those issues so they don't mess up your prints in mysterious ways.

    What were the failure messages?

    What does your Support/belt status read for slackness?

    Failure Message was "XYZ Calibration failed. Bed calibration point was not found.". It never got past the first point via Wizard. Everything worked fine when doing the XYZ Calibration via Calibration menu option.

    x 272
    y 267

    Posted : 05/01/2019 11:09 pm
    Bunny Science
    (@bunny-science)
    Noble Member
    Re: First layer test looks okay, but can't print Benchy

    I think your PINDA is right at the upper bounds of mounting height for the machine completing calibration. It's probably so close to the limit that the printer fails/succeeds XYZ calibration depending on ambient temperature. That might contribute to why you are getting such inconsistent results.

    I would loose the PINDA clamping bolt and lower the PINDA slightly. I'm guessing 1/4 - 1/3 turn based on your current Live-Z values. Be sure to retighten the PINDA clamp bolt.

    Redo XYZ cal after any move of the PINDA.

    You will need to determine your new Live-Z value. It will be more negative the lower PINDA is physically mounted.
    (Mine is low enough that Live-Z is -1.350)

    Posted : 05/01/2019 11:57 pm
    jim.w15
    (@jim-w15)
    Active Member
    Topic starter answered:
    Re: First layer test looks okay, but can't print Benchy

    After 1 wash with acetone (took me 2 stores to find it) and then preheating bed to 73F (it cools to 70 when first layer begins), I've been able to successfully print a few objects that look pretty good.

    I can probably fine tune it a bit to improve quality, but it looks as well as I thought it would/could look.

    As long as I use "brim" on Slic3r, then there's enough material to stick to the surface in case one bit comes up. I've had a few failures due to my lack of understanding of supports and printing/slicing techniques (I'm familiar with 3d object creation for use in video games and 3d modeling/terrain, but not with printing).

    I'm not sure what I did, but it seems to be working. Maybe I just needed to have a bunch of failed prints and a layer of acetone for everything to start working. Just hope it keeps going without any adjustments.

    I haven't tried Benchy again (needed to print a few small things at request of a kid). So I'll try Benchy again next week.

    Posted : 06/01/2019 3:44 am
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