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I am trying to print a 12 hole Ocarina I found on thingiverse. When printing I have to stop it around 25-30 layers because the edge of the shell is higher then the infill.

Example 1

Example 2

G-Code of first 30 layers

I tried changing the infill, wall size, speed and retraction settings to no avail. The settings of the example print were:

  • 100% infill
  • 0.2mm layer height
  • 40mm printing speed (average)
  • 1mm shell thickness (results in 2 layers)
  • Automatic infill patern
  • Printed at 210C with 3mm PLA (like this one)
  • Printed on a RF1000
  • Sliced with CuraEngine in Repetier-host V2.1.6.

Does anyone know what might cause this and how I can prevent it from happening?

Any help is greatly appreciated! :)

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    $\begingroup$ What kind of temps are you running this at? Everything is melted, which would imply you've got this thing running hot. Also, what type of filament? I don't see you mention either in your question, which is VERY important in giving a diagnosis. $\endgroup$ – Pᴀᴜʟsᴛᴇʀ2 Aug 12 '19 at 20:54
  • $\begingroup$ My bad forgot to mention. I use PLA and print at 210C. $\endgroup$ – Stefan Aug 12 '19 at 21:13
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    $\begingroup$ What size of nozzle are you using? What's your bed temp (if using a heated bed)? $\endgroup$ – Pᴀᴜʟsᴛᴇʀ2 Aug 12 '19 at 22:44
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    $\begingroup$ And are you sure you've got the printer set to print at 3mm and not 1.75mm for filament thickness? You are extruding a lot of material. $\endgroup$ – Pᴀᴜʟsᴛᴇʀ2 Aug 12 '19 at 23:20
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    $\begingroup$ PLA should be perfectly happy at 190-195. That will help with the melt and sag. $\endgroup$ – Carl Witthoft Aug 13 '19 at 14:35
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Managed to solve it by lowering the temperature to 190C. I also lowered the infill down to 25%. Thanks for the advice!

I posted the make with results and settings on thingiverse.

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  • $\begingroup$ There's serious overextrusion and stringing going on here. You may have filament size wrong and retraction settings badly wrong. If so, it's possible that lowering the temp and infill (esp lower infill will partly compensate for overextrusion) made it print okay-ish, but I think your expectations are just really low. $\endgroup$ – R.. GitHub STOP HELPING ICE Aug 18 '19 at 20:08
  • $\begingroup$ 190°C is quite low for PLA. It won't be a strong part. $\endgroup$ – FarO Aug 26 '19 at 14:39
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I think the solution in your self-answer is just a partial mitigation for an underlying problem, and your expectations for output quality are way too low.

From the pictures in the question, there's serious overextrusion and stringing going on. The stringing could be caused by a secondary problem (bad/insufficient retraction settings), but heavy overextrusion will cause there to be extreme residual pressure left between the extruder gear and the nozzle (especially in a bowden setup, though it's not clear what printer you're using or if it has a bowden tube) that retraction will be unlikely to sufficiently relieve, so it's also a characteristic consequence of overextrusion.

As Pᴀᴜʟsᴛᴇʀ2 noted in a comment, having the filament diameter set to 1.75 mm while your printer actually uses 3 mm filament could cause this. Cura (especially CuraEngine invoked via command line rather than the GUI) is particularly bad about getting this wrong if you don't pass the options in exactly the right way.

Note that lowering the infill percentage as you did would help get somewhat decent results with serious overextrusion, since the excess material has somewhere to go (into the unfilled part of the infill region). But you'll still be getting really bad (what I would call unacceptably bad) prints compared to what you could/should get.

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