Monday, November 16, 2009

Exploring support material in Skeinforge

Skeinforge has the possibility of generating support materials for overhangs for single extruder Reprap 3D printers. I decided to see how it worked. To do that, I created a dome in Art of Illusion and then cut away half of it.

Running it through Skeinforge...

The print began well...

...and progressed...

It was obvious that the extruder head was spending more and more time on a progressively small area as the dome print progressed.

You can see as well that waiting for temperature exchanges to take effect was causing a great deal of extruder dribble.  I discovered that you can get a raft off of your polypropylene print board if you print the first layer of the raft at 225 C and the second at 230 C.

If you then drop the temperature of the layer between raft and dome to 205 C it is fairly easy to get the print off of the raft.  This had been a problem at higher print temperatures.  The dome itself was printed at 230 C and the support material at 205 C.  While Skeinforge estimated the print time of this half dome at an hour it didn't estimate the time temperature changes in the extruder would take.  Those added another 1-2 hours to the print time.

Support material separated easily from the half dome.

Looking closely at the support structure it was well consolidated.  That left me to wonder what would have happened had I printed the whole half-dome at 205 C.

I wonder as well if a bit of moving air would have retarded the melting at the top of the dome.

It would seem as well that programming in significant wait times between layers would have given me a finer print.

I have quite a few parameters to twiddle in coming days.

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