Prusa is working again



  • The Prusa has up and running again. Lightly sanded and cleaned that bed. The wires were all in the right place. Recalibrated XYZ. Ran V2 calibration code. Live adjusted the Z axis.

    For future reference mineral spirits clean the bed glue off as well as limoene and goo gone is a waste of time.


  • Classroom

    Awesome @Grant-Fraser, thanks for the work!

    I would just add a cautionary mention that the mineral spirits should be applied as sparingly as possible so they are effective.

    They are probably more likely to react with the plastics and cause premature aging than limonene (i.e. turning the plastic brittle or causing it to warp). The spirits are a much more aggressive solvent for dissolving many organic compounds. As long as they aren’t left to pool on the surface, I would guess it is probably not going to be an issue but I haven’t actually looked up numbers for anything.


  • Design Lab

    @Grant-Fraser thank you and @pierre and whoever else has been working on this one!



  • I tried doing some pla prints tonight… Could not get a damn thing to stick to the bed. Which is sort of typical with me and PLA. I did not start getting good prints on the prusa last time until the bed had some time to break in.



  • Hey all, I’ve been having a lot of trouble getting my prints in ABS to stick to the bed.

    Thin extrusions won’t stick at all, peeling off as they are laid down. This is especially problematic if I am trying to use a brim or raft, or any support material.

    The only thing I have found to work so far is turning up my extrusion width on the first layer to 0.7mm (2x default width), which gets things started. I’ve had a few failed prints after that due to part shrinkage lifting the material corners off the bed.

    Any tips?



  • I was having similar trouble, @ColeVanD suggested I use the manual dial to turn up the flow rate for the first couple of layers until I get it good and stuck. Seems to help.



  • The print bed wasn’t heating, one of the wires that solders done to the bed had broken off.

    I did a quick and dirty splice on the wire to lengthen it and re-soldered that down.

    Works again.



  • Update: I couldn’t get any ABS to stick to the bed other than the test strip the printer does. My old settings that worked in the past wouldn’t stick today.

    Tried a really fat first layer (2.0 wide) cranked the plate up to 110°C and threw some glue stick down.



  • Don’t know what will get the prints to stick down?

    I cleaned the print bed thoroughly with Isopropyl Alcohol.
    I tried about a dozen prints tonight, mostly ABS. 80% were failed.
    Tried to switch to PLA using the default prusa settings, it wouldn’t stick at all.

    Please help?!



  • I’m printing a PLA model on the Prusa right now with NO PROBLEMS at all and I’ll tell you why…
    But first, a little rant.

    STOP SANDING THE DAMN PRINT BED !!!

    The Prusa uses a PEI bed surface and it will be DESTROYED by sand paper.
    PLEASE STOP !!!
    Sanding the print bed is the REASON nothing will stick !!!

    So why does it work for me?

    Easy, I don’t print where people have been sanding.
    It’s really that simple people. Sanding destroys the surface and nothin will stick where it was sanded.

    The bed corners are the only surface areas on the print bed that still have enough PEI to “properly” stick a print job.

    Also…

    People keep messing with the Z-axis height.
    I have done EXTENSIVE TESTING with this printer and a “live Z-Axis” height of about -0.770 works the best. If the extruder is too close, the printed lines will peel up at the ends. If it is too far away, the lines will just lift off the bed.

    Printing with PLA
    -Print bed alone will stick PLA, Nothing more needed.
    -Default temps work great!! [ 210 head, 60 bed ]

    Printing with ABS
    -Glue stick “may” be required. If the PEI surface is in good condition, nothing should be needed.
    -ENCLOSURE REQUIRED. All high temp plastics will warp without an enclosure. That includes both sticking to the bed and throughout the print job. It’s the ambient air temp that’s the problem here. It doesn’t matter if it gets to 40 deg in the MakerSpace, it will still cool the print too much, to quickly and will disconnect from the bed because of it.

    SOLUTIONS (because it was requested)

    1. Print in the corners (the un-sanded areas)
    2. Check and reset (when necessary) the Z-Axis height to approximately -0.770
      (Menus: Live Adjust Z-Axis…)
      Only available when print first starts.
    3. Get a new PEI print surface (…and DON’T SAND IT !!!)
    4. Build an enclosure for high temp plastics.

    I will be doing a 3D Printing Class in September at the Maker Space.
    I’ll be posting more about it in August once I have my stuff organized.

    Jason



  • Jason, thanks for advice.

    Getting individual advice like this out to Makerspace users is crucial to those users being able to use the 3D printer, and not spend frustrating hours seeing print after print get rejected.

    Right now it’s a goal of mine to get Individual knowledge like this out to the collective, by compiling a write up and problem tracking sheet that can be kept in a binder with the 3D printer. This would include:

    • Signage to indicate whether machine is functioning or down with issues (so that those with extensive experience can be drawn in to resolve)
    • Tips and tricks to resolve common “newbie” issues
    • Regular maintenance
    • Problems encountered and solutions specific to filament types etc
    • User generated printer config styles where someone can provide a quick description of changes and reasoning (for example lifting the z value higher after extruding to avoid strings)

    I’ve spent a lot of time asking around lately, and getting mostly shrugs in how to get a useful product out of this machine.

    One thing I’ve noticed is a little binding in feeding filament from the underside. I’ve been thinking of building a shelf so that the feed can come tangent off the spools and straight into each feeder. Thoughts?





  • @GHunter PEI bed ordered.

    Does anyone have a local source for the d-Limonene cleaner? If I don’t have a reply by Saturday night, I’ll go ahead and order that from Amazon.



  • @Grant-Fraser and I replaced the PEI last time we ordered stuff from prusa… Because it seemed like a cheap fix. It took many, many hours to clean off the old glue to get the new PEI to sit flat.

    Next time I have 200 bucks I want to burn, I plan to order this: https://shop.prusa3d.com/en/printer-upgrades/179-original-prusa-i3-mk2s-to-mk25-upgrade-kit.html

    That’ll give us a MK3 style steel bed with a magnet mount.



  • @pierre At some point I want to get it also! :)



  • @JasonH sorry if I angered you by sanding the print bed. Just following whatever instructions I can find on the internet. Perhaps we can repair the sanding by polishing it with steel wool or 2000 grit sandpaper.
    We have discussed making an enclosure. There is a wooden cart set aside for that project if anyone wants to take it on.



  • I can try and take that on.
    Makes sense to build a shelf for the spools into the enclosure.
    Lots of examples around:
    https://www.matterhackers.com/news/how-to-build-a-3d-printer-enclosure
    https://www.prusaprinters.org/cheap-simple-3d-printer-enclosure/

    I see the power supply is best kept outside the enclosure (doesn’t want to get too hot), some people add in ventilation and filtration.

    Reading through the old thread where the cart is mentioned. What’s the intent there? A computer is also to be mounted on the cart?



  • @Torren we used mineral spirits last time. The can should be in the paint cabinet.i would put a shop cloth on the plate, soak it with mineral spirits, and cover it with a pane of glass to keep it from evaporating.



  • @ghunter
    Good conversation is what is going to get us organized, educated and setup for 3D Printing here at the Makerspace :-)
    Seeing the many quick responses makes it clear that we all care about setting things up for the benefit of all :-)
    A training class (in the works) and a Do’s & Don’ts binder are important pieces too.

    @pierre
    The MK3 print bed would be a FANTASTIC upgrade !!!
    Here it is in writing… I will contribute $50 to that effort if others want to see it as well.

    @Grant-Fraser
    What !?! Me…”angered” ?!? <insidevoice> HULK SMASH</insidevoice>
    …but seriously… we all just need to be on the same page and this conversation is getting us there !!! Clearly, we all want the same thing.

    The cart is a fantastic idea and it is mostly completed too. An enclosure and spool holder will top it off nicely! The cart with a transparent enclosure will make 3D Printing classes much more effective as more people will be able to see whats happening.

    Jason



  • The cart we have is the plywood cart that floats between the hack room and the hallway. It isn’t ideal and requires moving the middle shelf and making the top bigger. Starting over might be a better idea.

    We did have plans to keep the computer and monitor on the cart as last minute design changes happen. Other ideas included a thermostatically controlled vent fan. Filtration probably isn’t needed as odour hasn’t been an issue. We expected the printer to smell way worse based on the online descriptions.

    Ultimately the design will be what the person who wants to put in the effort says it will be.



  • @pierre @Jason
    I’ll throw $50 in also.

    @Grant-Fraser
    Ok, was the intent to put the printer in top or somewhere in the middle?
    The downside to a cart is it takes up more floor space, but maybe mobile has some advantages?


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