Jump to content
Ultimaker Community of 3D Printing Experts

First layer adhesion question


Recommended Posts

Posted · First layer adhesion question

http://www.youtube.com/watch?v=rpi39ISmedk

As you hopefully can see in the video sometimes on the first layer it seems like the pla does not want to stick at all to the bed in some spots. Is this from a dirty plate or would something else be the cause? Sorry if this is a dumb question It just seems odd because I have pretty good adhesion most of the time.

Thanks Mike

 

  • Share this post


    Link to post
    Share on other sites
    Posted · First layer adhesion question

    It could be due to the bed being slightly off-level, so that in some parts the head is a touch too close to the bed; the plastic can't escape properly, so pressure builds up, and then it escapes in a blob when the pressure is high enough.

    Are you using any adhesive on the bed, or just printing straight onto the glass?

     

  • Share this post


    Link to post
    Share on other sites
    Posted · First layer adhesion question

    It could be due to the bed being slightly off-level, so that in some parts the head is a touch too close to the bed; the plastic can't escape properly, so pressure builds up, and then it escapes in a blob when the pressure is high enough.

    Are you using any adhesive on the bed, or just printing straight onto the glass?

     

    Straight on the glass, I have had a lot of problems actually getting the correct bed level. Not only have I had trouble keeping the bed even but I also had trouble with how close I was. Do you have any tips?

     

  • Share this post


    Link to post
    Share on other sites
    Posted · First layer adhesion question

    If you print straight on the glass you need to heat to at around 40 or 50C (or hotter - 70C is recommended but 50C is fine).

    Are you using a piece of paper during levelling? It should just barely touch the paper enough to be slightly tighter than completely loose. In other words once it is tight enough that you notice restriction in movement then you are close enough. Also it is best to level with a hot nozzle and a hot bed for two reasons:

    1) hot things expand so you want to level with same conditions as printing

    2) sometimes there is a tiny tiny blob of pla on the end of the nozzle. If that is hot then it shouldn't hurt your leveling procedure.

    I have only levelled my UM2 once about a month ago and haven't messed with the levelling since then! :)

     

  • Share this post


    Link to post
    Share on other sites
    Posted · First layer adhesion question

    I have seen the same behaviour. I don't think it's due to pressure building up. If you look very closely as the head is laying down the plastic you can see that it exits the nozzle without any issues but in some spots it immediately disconnects from the surface of the glass. It looks sort of like if you would take a piece of tape, clean off the adhesive in a spot near the edge and then stick it down. The part without adhesive will lift slightly from the surface.

    I noticed that some of my filaments are more likely than others to do this. The effect seems to be reduced if you print a very thin initial layer, I like 0.1mm (this requires a very flat bed when printing on glass, ye olde blue tape was more forgiving). I also tried putting on a VERY thin layer of glue, barely putting any pressure on the glue and spreading it super thin worked well for me while keeping a shiny bottom surface.

    As for bed leveling. Make sure that the head of the printer (the fan shroud more specifically) isn't hitting the metal clips holding the glass in place as that will screw up your bed leveling.

     

  • Share this post


    Link to post
    Share on other sites
    Posted · First layer adhesion question

    I use extra strength hair spray on my glass which I have found to be very good for both PLA and PLA/PHA. Temp. set to 60 degrees as measured with a digital thermometer

     

  • Share this post


    Link to post
    Share on other sites
    Posted · First layer adhesion question

    If the print head is too close to the glass, and the glass is too hot/cold, and the print temp is too low, the friction from the printer movement will tear off parts of the print. print the first layer 5-10C hotter, and lever your bed properly.

     

  • Share this post


    Link to post
    Share on other sites
    Posted · First layer adhesion question

    It actually seems like the problem I was having was oils from my skin preventing adhesion in some spots.

     

  • Share this post


    Link to post
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
    • Our picks

      • Talking additive | The 3D printing podcast
        Why should we be the only ones asking questions? Join us and ask Jabil all your questions on September 22nd 5pm CET
          • Like
        • 3 replies
      • Ultimaker masterclass: Optimizing your Ultimaker Cura workflow
        Save your seat for either broadcast on September 23.
        What will you learn?
        · Best practices for iterative print preparation and every lesson you should learn from each print
        · The right way to use per-object settings and when they are most useful
        · Easy-to-use resources for anyone who wants to develop their own printer definitions, plugins, or print profiles
        · How to optimize print profile settings and whether to “keep” or “discard” changes
        · When is the right time to export your drawing from CAD? (Based on Ultimaker Cura’s surprising power as 3D control software)
        · And a whole lot more tips and tricks!
         
        How can I join?
        This free masterclass will take place twice:
        1. 11am CEST (5pm SGT, 5am EDT)
        2. 5pm CEST (11am EDT, 8am PDT, 11pm SGT)
          • Like
        • 0 replies
      • Do you use 3D printing at work? Let us know
        It doesn't matter if you are using 1 Ultimaker or 10, there is inspiration in everything. We're looking for ...
        • 1 reply
    ×
    ×
    • Create New...