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I recently changed the printhead on my DeltaMaker from stock to an E3D Lite6, and am struggling to get back to my original quality, reliability, and repeatability. I thought I had gotten the recipe pretty close to dialed in and tried a bigger print last night. It turned out pretty good in most respects except for where vertical structures rise up from the horizontal surface (and a retraction/stringing issue that I didn't think was but perhaps could be related).

The screw hole mounts seem well-designed to me:

3D print preview

No 90 degree transitions - I would think this would be the least of my problems. But last night they had serious problems:

Example 1

Example 2

I haven't seen a problem like that before. Extrusion rate seems basically perfect - why does it look like it just stopped extruding around the perimeters?

I'm using PLA filament and Simplify3D 3.1.0 slicing. Settings:

  • 0.35 mm nozzle, 0.40 mm extrusion width, 1.05 extrusion multiplier
  • 0.15 mm layer height, 3 top, 3 bottom layers, 2 perimeter shells (maybe should try 3?)
  • 30% infill, 60% outline overlap, 110% infill extrusion width
  • Temp is 220°C (thermocouple wedged between nozzle and heater block reports about 206°C when thermistor says 220°C)
  • Print speed is 2700 mm/min (45 mm/s)

Has anyone seen this issue before?

UPDATE: Increasing outline overlap from 60% to 90% almost fixes the problem (at least visually if not structurally) - there's just one small hole at the base of each structure. (I stopped the print a few layers after the problem layers do ignore the tops.)

Updated Image

Going to 99% (Simplify3D's max) would probably get rid of those last holes but I have to think that maxing out S3D's outline overlap setting to just barely make the print work means I haven't found or addressed the true root cause...

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Since you said you don't have a cooling fan, try lowering the temperature on your print head to something like 205. The strings in the first and second picture also occur more often when the print temperature is too high as well.

The layer time gets really small at that transition, so make sure the print speed is slowing down while printing that part of the object and pausing in between those layers to allow for cooling.

It looks like the plastic is still molten and is being dragged around too me.

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It looks like the first layers that are making the vertical transition do not have enough to stick to and are curling up. Are you using a cooling fan?

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  • $\begingroup$ Hi welcome to the site! I see you've been quite active answering questions, but this isn't really an answer to the question, and would be more suited as a comment (you will be able to leave comments once you have 50 reputation). This answer is quite short, and skips over a lot of potential solutions. Please see the help center on how to write a good answer. $\endgroup$ – Tom van der Zanden Oct 23 '16 at 7:09
  • $\begingroup$ @Jexoteric - No fan for the print, but that hasn't been a problem historically with this printer (maybe that changed with the new hot end?), and I can't understand why it would only fail to attach at the relatively mild sloping part when it's so solid on pure horizontal or pure vertical surfaces... $\endgroup$ – Fred Hamilton Oct 23 '16 at 18:29
  • $\begingroup$ Is the tip of the extruder a significantly different size, such that it could flatten the trace width more or less than it could previously? $\endgroup$ – Jexoteric Oct 23 '16 at 19:52
  • $\begingroup$ Nope - old and new nozzles were both 0.35mm. $\endgroup$ – Fred Hamilton Oct 23 '16 at 22:26

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