No strings attached
A great improvement in printing quality is now possible.
The hollow piramid being printed is this thing on Thingiverse.
Summary: There are several ingredients to minimize or even eliminate ooze on an Ultimaker:
- Some experimentation
Only the combination of them gets you the best result.
One is the dwindle feature in Skeinforge (integrated in ReplicatorG and Cura). It will turn off extrusion a bit before it needs to stop and slows down. Another one is rapid reversing. Because of the stepper based extruder design, reversing doesn't need to take very long. Ooze is further minimized by shortening the time it takes to travel from section A to B. Because the feed rates can go up to 300 mm/s the extruder only has a short amount of time to ooze. Another option, currently used in the Java host, but not in Skeinforge (yet), it to always let the ooze end up on the inside of the object. Still, the "comb" feature in Skeinforge lets most of the dripping end up inside the object by smearing it across the already printed inside of the object. When a void needs to be crossed, it tries to find a short path to cross it.
Cura currently is probably the easiest to se up for reversing and stringless printing.
- A knurled bolt kit (version 3 is more or less a requisite!)
- A 3D printable Ultimaker Quick Connect Shim (on Thingiverse.com)
With experimentation you'll find that you'll especially vary the retraction length. This should actually become a dynamic value, because it may vary with print speed and temperature.
This would not have been possible without the many contributors, among which:
- Florian Horsch - for his research and coordination of many contributions
- Paul Candler - for pioneering the best reversal settings that were known for Ultimaker
- Daid - for making Cura! An accessible 3D printing environment
- Taylor Alexander
- Geo Hagen
- Bernhard Kubicek
- Enrique Perez - Skeinforge
- And many more!