The Printer and the Box of Doom

I’ve just started printing for hore fairly recently and the 3D printing gods have already decided to take me to the woodshed…

I present to you the box of doom…

It looks innocent enough.  It’s a simple box for storing a puzzle.  There shouldn’t be any problems printing it. Right?


At first I thought the nozzle had jammed either due to filament diameter inconsistency or else a partial clog in the nozzle.  I took a cleaning needle, poked around in the nozzle, and extruded some filament.  Everything seemed to be working fine so I tried the print again.  The same thing happened at the same location.  So now I decided to take a look at the box in the print preview in Cura and step through one layer at a time.

This was at layer 53.  So far so good.

In next layer It looks like a top layer is being inserted in about 1 third of the print walls.  This continued on for a couple of more layers and then this appeared.

It appears it’s trying to print part of a bottom layer and it jives with what was actually being printed.

I suspect someone tried to do a mashup of two boxes and botched the layer cut and boolean union.  Anyway I put the STL in Meshmixer and did a Make Solid with a 256 Accuracy/Mesh Density,  exported the new file, and looked at the layers again in Cura 4.8.  The problem was still there.  This time I tried the Close Cracks operation. I looked at the exported file again and this time the phantom layers were gone.

I was able to print the box again without a hiccup.


So what’s the take home here?

  1.  There’s no such thing as an “innocent” looking STL.
  2.  Rather than assume somthing went wrong with the printer step through the model layer by layer to make sure there are no defects like the one I just showed you.


Happy Printing Everybody!