My last layer looks like this on my model.

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(Jonas G.) #1

My last layer looks like this on my model. How can I avoid this?

(Petr OK1RP) #2

Is it PLA?

(Daniel Bull) #3

You need to either set your slicer to over extrude the first layer or adjust your z height so its closer.

(Michael Schroeter (MiSc)) #4

Try different layer height!

(Jon Gritton) #5

Hi @Jonas_G it could be a couple of things either/or/both. I’d look at both your extrusion setting and your perimeter overlap as it looks like both could be on the low side here. I’d recommend modelling (or finding) a very simple test cube that you can use for testing at various settings. Print multiple copies and note down which settings were used for each (label the cubes A, B, C, etc.).

(Jeff Parish) #6

Also, looks like you don’t have enough layers on the top surface. What are your top layers thickness set to in your slicer? I set mine to be 6-8 times the layer height. At a minimum there needs to be 4 layers for a top surface.

(Mark Wheadon) #7

+1 on the under-extrusion. Look at the outer perimeters – you can see each one is slightly separated from its neighbour. If you can on your printer, just select ‘flow’ and set it to, say, 108%, whilst the job is printing, before it gets to the top layers, and see what you get then…

(Neil Darlow) #8

This being your TOP layer, your layers should have stabilised by then so forget first layer issues.

There’s a feed problem here as evidenced by the broken inner perimeter. I was tempted to say it’s under-extrusion but I think feed issues are the underlying cause.

I would try the following:

  1. Try to manually extrude a little filament and see if it flows cleanly as a vertical string. If it doesn’t, you could have a partial nozzle clog.

  2. Ensure your slicer Flow Rate or Extrusion Multiplier is set at 100% or 1.0 respectively. Values below this don’t help in diagnosing this type of problem.

  3. Reslice and check using the slicer preview or online G-code viewer like gcode.ws. You should be able to assess the infill quality with these tools.

  4. Recalibrate your extruder steps/mm using the measured length method after assuring yourself that filament flows freely from step 1) above.

I would have expected you to notice your filament feed motor skipping steps with a clicking sound to produce that result.
http://gcode.ws

(Jonas G.) #9

@Petr_OK1RP it is bronze based PLA Filament

(Jonas G.) #10

thank you all! I will look in to this tomorrow

(IDM Imagineering) #11

6 to 10 top and bottom layers

(Jon Gritton) #12

I’d just add that in terms of top and bottom solid layers, I tend to work on a thickness/number of layers combination rather than just number of layers. There’s little point in having 10 solid layers if your layer height is 200 microns+ and equally 5 solid layers may not be enough if you’re printing at 25 microns. I usually aim for a 1mm thickness with a minimum of 4 layers, but it will also depend on the model. With a “thin” shape like this I’d expect the solid layers to fill pretty well, with a larger “wider” model I might add a couple more.

@Jonas_G you say this is “bronze based” - is it actually a metallic filament? If so, are you using a hardened nozzle and full metal hot end? What’s your nozzle size? Many “exotic” filaments don’t work well with nozzles below 0.5mm.

(Kevin Danger Powers) #13

@Jonas_G I would also double check that your slicer isn’t set to the wrong nozzle diameter. Cura defaults to 2.85 so I always have to change it whenever I reinstall the software.

(Jonas G.) #14

@Jon_Gritton yes, it is metallic filament. To be exactly this one: https://www.3d-printerstore.ch/3D-Filament-Resin/3D-Filament-1-75-mm/Glitter-Metalic-1-75mm/Metal-ProFill-bronze-1-75mm-750gr::1240.html
Right now I use a normal nozzle. I know I should use a hardened nozzle.

(Daniel Bull) #15

You can use a normal nozzle but be aware it will open up the aperture slowly.

(Jonas G.) #16

@Jeff_Parish mine is set to 3 times the layer height

(George Belev) #17

You may check the following link: https://all3dp.com/1/cura-tutorial-software-slicer-cura-3d/
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