Jump to content
Ultimaker Community of 3D Printing Experts

print quality varies on z axis


alaris2
 Share

Recommended Posts

Posted · print quality varies on z axis

I've seen this apparent on several posts including prints of my own - the printer is well set up and works fine, but prints of repeating layers eg. a cylinder, cube or other simple shape where each layer is essentially the same, will have variations in quality on the z axis.

this is seen as differences in color, or thickness, ie. the amount of material extruded.

now we now that variations in filament diameter can cause exactly this problem. layers may extrude too little and string excessively, or worse may be missing entirely such that the next layer prints in thin air.

however in my own case, the filament is fine, variation of <=0.01mm

I can also print many layers (1/2" at a time) at excellent quality and layer adhesion. then all of a sudden I get a bad layer - if it's bad enough, the whole print will fail.

I was thinking of blaming the hobbed bolt, which had a fair amount of plastic on it, as slipping. but a clean later, and no real improvement. I believe the tension of the thumbwheel to be correct (otherwise I wouldn't get as many good layers as I do would I?)

any other suggestions from folks? should I just change for another extruder design entirely? do those with the other extruders get more uniform print quality across layers.. or is it just a different set of problems to face?

  • Link to post
    Share on other sites

    Posted · print quality varies on z axis

    Try to feel on the frame if you can feel any vibration from the fan. I noticed that I got different quality at different layers in the print apparently because the PCB fan below the printer changed speed during the print (however I noticed it in roughness of the surface, not amount of extruded material, so it might not be the same). Try to detatch the PCB+fan from the UM and see if it helps.

  • Link to post
    Share on other sites

    Posted · print quality varies on z axis

    strange you should mention roughness - I just had a print failed on me after about the 3rd layer. the machine hadn't been on long enough surely to have z motor overheating problems (I don't think?) although it doesn't rule out too little power. I'll try again with the fan off. thanks!

  • Link to post
    Share on other sites

    Posted · print quality varies on z axis

    so I probably shouldn't have done that...

    I unplugged the board fan. it made a change to have a quiet print.

    on the second layer I noticed a strange X and Y offset, then I noticed the extruder motor was just going click click click.

    then I stopped everything.

    the extruder motor still went click. it was trying to move one notch and failing, so I powered everything off and pulled the filament out of the hot end.

    it sounds like bad news.. is this the noise/symptoms of a hot end plug?

    I thought the board fan wasn't strictly necessary except in very hot climates, presumably me having it off caused overheating somewhere. it's only 15C ambient in this room right now tho!

  • Link to post
    Share on other sites

    Posted · print quality varies on z axis

    Sorry if I was unclear. I didn't want you to unplug the fan, just detatch it from the UM, so the vibration didn't transfer to the print.

    I hope the board is still ok, it shouldn't be broken in such a short time. (If it is broken I will pay for the repairs since I somehow feel responsible...)

  • Link to post
    Share on other sites

    Posted · print quality varies on z axis

    I have a similar problem with the Z axis sticking, i have removed the spindle from the steeper, and moved the platform up and down

    with the smooth rods in place, and even with oiling the bearings are rough.

    I also find i have issues with prints at the 10mm layer, as the platform drops to 10mm when you start prints etc, so its a common height

    the printer goes to a lot.

    It would be good if somewhere you could very the height (eg between 8-15mm) when the platform drops for a test extrude before a print starts, so

    any wear is varied.

  • Link to post
    Share on other sites

    Posted · print quality varies on z axis

    oh don't worry frodeheg, I understood your post perfectly. the decision to unplug the fan was mine since it's incredibly noisy anyway and I've been meaning to replace it for ages now. I doubt the board is broken but I'll have a proper look tomorrow - I'm more concerned about understanding those strange click noises from the extruder motor and why they continued even after clicking the 'disconnect' button.

  • Link to post
    Share on other sites

    Posted · print quality varies on z axis

    well for the benefit of others, the variation is at least partly due to the steppers needing fine adjustment, as detailed on

    http://wiki.meta-concepts.com/display/U ... Adjustment

     

  • 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
     Share

    • Our picks

      • New here? Get ahead with a free onboarding course
        Hi,
         
        Often getting started is the most difficult part of any process. A good start sets you up for success and saves you time and energy that could be spent elsewhere. That is why we have a onboarding course ready for
        Ultimaker S5 Pro Bundle, Ultimaker S5, Ultimaker S3 Ultimaker 2+ Connect.   
        They're ready for you on the Ultimaker Academy platform. All you need to do to gain access is to register your product to gain free access. 
        Ready? Register your product here in just 60 seconds.
          • Like
        • 11 replies
    ×
    ×
    • Create New...