slic3r.org »

Slic3r Manual

This page will provide an overview of the available configuration settings in Slic3r. Every configuration option has a tooltip and it is recommended to read those tooltips.

The Print Settings tab provides the opportunity to change settings related to the actual print. Whereas the other tabs are changed rarely, the settings on this tab will be modified regularly, possibly for each model printed.

Print Settings: Layers and Perimeters

Print Settings: Layers and Perimeters

General.

Layer height is the thickness of each layer, and it is the step along the vertical axis taken before extruding a new layer atop the previous one. There are several factors that influence how high each layer should be:

Perimeters defines the minimum number of vertical shells (i.e. walls) a print will have. Unless the model requires single width walls it is generally recommended to have a minimum of two perimeters as this gives some insurance that if a section of the perimeter is not printed correctly then the second perimeter will help cover it.

The upper and lowermost layers that sandwich the model are filled with a Solid layers pattern. For the bottom layers the important factor to consider is how the surface will look should there be a mistake whilst laying down the first layer, and for this reason it is recommended to have at least two bottom layers.

A similar consideration is required for the top layers. Because the intermediate layers are likely to be filled with a pattern set less than 100% then the covering layers will have to bridge this pattern and this can require more than one pass to cover completely.

An example of insufficient top layers.

An example of insufficient top layers.

Another tip to consider: Setting the top solid layer to zero, and setting the infill also to zero, will result in a hollow receptacle, ideal for turning models into vases1 for example. Here manipulating the settings within Slic3r can be used to generate different kinds of prints, and not only be used to control surface accuracy.

Creating a vase from a solid model.

Creating a vase from a solid model.

Infill.

Print Settings: Infill

Print Settings: Infill

Fill density is from 0% to 100%. it makes no sense to 100% fill the model with plastic, this would be a waste of material and take a long time. Instead, most models can be filled with less material which is then sandwiched between layers filled at 100% (see Solid layers above).

A density value of 40% is enough to give almost all models good mechanical strength. A value of 20% is usually the minimum required to support flat ceilings.

Slic3r offers several fill patterns which will be discussed in more depth in section - Infill Choices. Choosing a Fill pattern will depend on the kind of model, the desired structural strength, print speed, and personal taste. The more exotic fill methods are usually too slow and unnecessarily complex for most use cases, and so most of the time the infill pattern is either rectilinear, line, or honeycomb. Honeycomb gives the most strength but is slower than both rectilinear or line.

Infill Patterns

There are several considerations when choosing an infill pattern: object strength, time and material, personal preference. It can be inferred that a more complex pattern will require more moves, and hence take more time and material.

Slic3r offers several infill patterns, four regular, and three more exotic flavours. The numbers given in brackets below each figure are a rough estimate of material used and time taken for a simple 20mm cube model2. Note that this is only indicative, as model complexity and other factors will affect time and material.

Infill pattern: Line (344.51mm / 5m:20s)

Infill pattern: Line (344.51mm / 5m:20s)

Infill pattern: Rectilinear (350.57mm / 5m:23s)

Infill pattern: Rectilinear (350.57mm / 5m:23s)

Infill pattern: Concentric (351.80mm / 5m:30s)

Infill pattern: Concentric (351.80mm / 5m:30s)

Infill pattern: Honeycomb (362.73mm / 5m:39s)

Infill pattern: Honeycomb (362.73mm / 5m:39s)

Infill pattern: Hilbert Curve (332.82mm / 5m:28s)

Infill pattern: Hilbert Curve (332.82mm / 5m:28s)

Infill pattern: Archimedean Chords (333.66mm / 5m:27s)

Infill pattern: Archimedean Chords (333.66mm / 5m:27s)

Infill pattern: Octagram Spiral (318.63mm / 5m:15s)

Infill pattern: Octagram Spiral (318.63mm / 5m:15s)

Certain model types are more suited for a particular pattern, for example organic versus mechanical types. Figure shows how a honeycomb fill may suit this mechanical part better because each hexagon bonds with the same underlying pattern each layer, forming a strong vertical structure.

Infill pattern comparison in a complex object. Left to Right: honeycomb, line

Infill pattern comparison in a complex object. Left to Right: honeycomb, line

Most models require only a low density infill, as providing more than, say, 50% will produce a very tightly packed model which uses more material than required. For this reason a common range of patterns is between 10% and 30%, however the requirements of the model will determine which density is best. Figure shows how the patterns change as the density increases.

Infill patterns at varying densities. Left to Right: 20%,40%,60%,80%. Top to Bottom: Honeycomb, Concentric, Line, Rectilinear, Hilbert Curve, Archimedean Chords, Octagram Spiral

Infill patterns at varying densities. Left to Right: 20%,40%,60%,80%. Top to Bottom: Honeycomb, Concentric, Line, Rectilinear, Hilbert Curve, Archimedean Chords, Octagram Spiral

There are several 3D patterns available for 3d infill as well.

Infill Optimization

Slic3r contains several advanced infill settings which can help produce better extrusions.

Support material

Print Settings: Support Material

Print Settings: Support Material

Printing a model from the bottom up, as with FDM, means that any significant overhangs will be printed in the air, and most likely droop or not print correctly. Choosing support material (Generate support material) will add additional structures around the model which will build up to then support the overhanging part. The Pattern spacing option determines how dense the support material is printed.

An example of an object printed with support material.

An example of an object printed with support material.

Tip: It is sometimes worth considering altering the orientation of the model in order to possibly reduce overhangs.

Raft layers will add additional layers underneath the model and stems from the early days of 3D printing. The following use cases are appropriate for raft usage: - Print is using a material that usually requires a heated bed to not warp and there is no heated bed. - The bed is not very flat. A raft then absobes the variance in Z for the first layer. - The part has a very small contact area with the bed. Usually a wide brim is a better solution.

Otherwise, rafts are generally not recommended. The raft also requires post-processing to remove it.

Rafts are classified as support material, while the top layer of the raft (the one directly underneath the model) is interface material and as such uses those settings.

Speed

Print Settings: Speed

Print Settings: Speed

There are two general categories of speeds: print moves and non-print moves.

For print moves, each type of printing move can be configured to have a different speed, either in absolute terms (mm/s) or as a percentage of the more general move.

The one non-print move is travel moves.

All print moves on the first layer may be changed with the provided modifier, either as a flat percentage or a fixed speed.

Acceleration

If your printer firmware supports acceleration control, you can enter in values here to change acceleration for the different general print moves.

Autospeed

If you set any print speed value to auto, configure the fastest printing speed you want for this print and Slic3r will choose speeds itself in an attempt to maintain constant pressure in the extruder.

Setting Max volumetric speed will tell Slic3r to not exceed the given flow rate for any printing moves. Set it to 0 to disable this feature.

There are 2 experimental methods to derive the max extrusion rate:

  1. Print fast and use live tuning via M221 until you see or feel the filament slipping in the extruder (easy on a standard UM, maybe more difficult on others, and it heavily depends on the extruder mechanism how much pressure it can deliver without slipping).
  2. Perform the following extruder calibration routine (either manually in pronterface, or with some to-be-done tool): Heat the printe's hotend up a middle of the road temp (i.e. 210C for PLA), and push i.e. 20mm filament through the nozzle at a given speed (steps/sec or mm/sec), starting with i.e. 1mm/s, and observe whether or not the filament was slipping. If not, continue increasing the speed by 20%, and test again. If so, this value indicates a maximum extrusion rate for this temperature has been reached.
Recommendations

Once the printer is reliably producing good quality prints it may be desirable to increase the speed. Doing this provides several benefits, the most obvious of which is that the results are produced quicker, but also faster print times can be utilised in producing more layers, i.e. lower layer height, thus improving perceived print quality. An additional benefit is that a faster travel movement, between extrusions, can reduce the effects of oozing.

The best approach is to increment the various speed parameters in small steps and observe the effect each change has on print quality. Travel speed is a safe starting point, and it is not unrealistic to attain speeds of up to 250mm/s (if your printer can handle it). Adjusting the speed of perimeters, infill is available in simple mode, and the general rule is to have the perimeter go a little slower than the infill in order to reduce possible blemishes on the surface (infill can be faster because slight gaps will not matter as much).

Skirt and Brim

Print Settings: Skirt and Brim

Print Settings: Skirt and Brim

Brim

Brim width is used to add more perimeters to the first layer, as a base flange, in order to provide more surface area for the print to stick to the bed with in order to reduce warping (see §). The brim is then cut away once the print is finished and removed from the bed. Interior brim width adds a brim inside of holes in the print.

An example of brim.

An example of brim.

Skirt

The Skirt setting adds an extrusion a short distance away from the perimeter of the object. This can ensure that the material is flowing smoothly from the extruder before it starts on the model proper.

Extrusion Width

Extrusion widths options.

Extrusion widths options.

One reason for modifying the extrusion width has already been discussed: increasing first layer extrusion width in order to improve bed adhesion (see p.). There are some further cases where it may be beneficial to modify extrusion widths.

It is important to remember that if the extrusion width is expressed as a percentage then this is computed from the Layer height property, and not the Default extrusion width setting.

G-Code Output Options

Print Settings: Output Options

Print Settings: Output Options

Sequential Printing.

This feature allows to compose a plate of objects but have the printer complete each one individually before going back to Z = 0 and starting with the next one. See the section about Sequential Printing in the Advanced Topics chapter.

Output File Options
Post-Processing Scripts

Post-processing scripts are a powerful way to modify output G-Code after the slicing process has completed and as such have their own section in Advanced Topics.

Shortcuts

Print Settings: Shortcuts

Print Settings: Shortcuts

For configuration options that you modify often, Slic3r provides a way to pre-register those options so that they are configurable from the plater. Simply check a box for each.

Profile Compatibility
Print Settings: Compatible Printers

Print Settings: Compatible Printers

Use this dialog to mark which printer profile(s) this print profile can be used with. The default is to "All" printer profiles.


  1. http://slic3r.org/blog/tip-printing-vases

  2. Taken from http://gcode.ws