Release notes for 0.9.8 (2013-01-16)

After much much work on stability and surface smoothness we have a new 0.9.8. Give it a chance, download it and enjoy!

Hidden work was done on the regression test suite coverage. Also, important work is sitting in three branches waiting to be merged right after this release (it wasn’t tested enough for inclusion in this one). Expect more goodies soon.

Thanks to Mike Sheldrake for working on many issues, and to donors and sponsors for funding the project. Thanks to Angus Johnson (author of the Clipper library) too for prompt response about arising issues and his quality work. Also, thanks to the wonderful community making this open source project pure fun.

New features:

  • acceleration control (advanced setting) to control behavior for perimeters and infill
  • customizable G-code to be executed on tool change ([previous_extruder] and [nextextruder] placeholders can be used, as well as nested placeholders like [temperature[next_extruder]])
  • automatic detection of support material threshold angle (leave it to zero and Slic3r will check your layer height and extrusion width to detect unsupported overhangs)
  • experimental feature for vibration limiting (not needed in 99.9% of cases, might be handy with some shaky printers)
  • support for a Sailfish G-code flavor (I can’t test this one, so please provide feedback)


  • plater will show vertical projection (with holes) of objects instead of their convex hull (limited to models with less than 2000 triangles for now - performance reasons)
  • gap fill is always disabled when fill density is zero; you can also set gap fill speed to zero to disable it
  • slight memory and time savings
  • automatic extrusion width defaults to way saner behavior when using low layer heights, avoiding infill to be too sparse


  • cooling is enabled by default now


  • many (all?) spikes/blobs removed, causing not very smooth surfaces when high-res models were processed
  • wrong direction was detected for many bridges
  • infill every ‘n’ layers was stalling or generating tiny useless extrusions
  • the experimental inwards move that was recently introduced to avoid retracting on external perimeters was sometimes moving outwards (!) causing a little blob
  • some top/bottom solid shels were not treated as such
  • some holes were filled/bridged incorrectly
  • crash on Windows when username or STL/G-code paths contained non-ASCII characters
  • interface support material layers were clipped badly causing extrusions running into object perimeters
  • slow infill patterns were not working anymore
  • extra perimeters were not always applied when needed
  • custom layer-change G-code was applied before Z change
  • fixed regression causing inefficient infill paths
  • restart_extra_length didn’t work correcty with negative values
  • retraction lift was not playing well with retract_extra_length in multi-extruder environments