Cura is the slicing software provided and recommended by Ultimaker for use with their printers. Slicing is the process of converting a 3D model into the instructions for the 3D printer (such as temperature settings for the print head and bed, where to move the print head, and how much material to extrude).

Cura offers great support for the Ultimaker printers, including the ability to get configuration information (the currently loaded filament) directly from the printer, and the ability to monitor prints in progress. Cura is easy to use, and offers a choice of a few recommended settings and a rich collection of custom settings. Here are a few recommendations for improvement:

  • In some cases, Cura will report that it is Unable to Slice the model. This may occur even if the user has selected "Center Model on Platform." With models that are close to the maximum build area, manually moving and rotating the model to get it to fit can be a tedious process. It would be great if Cura offered the option to automatically position and rotate the model for the best fit in the build area.
  • Some Cura options may lead Cura to report that it is Unable to Slice the model, even if it actually would be able to slice the model. For example, selecting a Brim for Build Plate Adhesion may lead Cura to report that it is Unable to Slice the model because a Brim (like the brim of a hat) increases the size of the model. However, if the model is actually narrower at the base than it is higher up on the model, the Brim would not actually increase the required build area. It would be great Cura offered the option to "Slice Anyway." In some cases, the slicing would succeed, although is some, many, or most cases, the slicing might fail.
  • When printing with multiple extruders (support material or multiple colors), the build area is slightly narrower than when printing with a single extruder, because Extruder 1 can not reach the extreme right side of the build area, and Extruder 2 can not reach the extreme left side of the build area. Thus, Cura sometimes reports that it is Unable to Slice even if slicing might be possible, for example because no support material is required on the left side of the model. It would be great if Cura offered the option to "Slice Anyway, and do your Best." In this case, Cura might use Extruder 2 for support material in all places where Extruder 2 can reach, and use Extruder 1 for support material in places (if any) where Extruder 2 can not reach. This would be preferable to forcing the user to use Extruder 1 for all support material.
  • It would be helpful if Cura offered an option to view the support structure. This might be helpful in choosing the optimum Cura options. In some cases, the support structure is very fragile (tall and narrow) and may prematurely detach from the build platform. In other cases, it appears as if unnecessary support material is used (for example on a gently sloping surface that does not require support).
  • It would be nice if Cura offered a printable manual in PDF format. Currently, the Cura reference is only available online in HTML format and not as a single printable document.
  • Saving a Cura project appears to generate a double set of extensions (e.g. UM3E_model.curaproject.3mf.curaproject.3mf). The file must be manually renamed to remove this double set of extensions. When saving a project whose name already begins with UM3E_, Cura still prepends this prefix, resulting in a double prefix (UM3D_UM3E...).
  • Saving a Cura project always prompts for the filename to save. Thus, the menu should really be Save project as...