Support is very important in 3D printing, as it is inevitable to encounter models with large overhangs. Bambu Studio is equipped with rich features of support. For a quick start, please refer to these videos.
There are 2 basic types of support: normal and tree. The main difference between the two types is:
normal support directly projects the overhangs down to the heat bed, and gets the support body;
tree support samples the overhangs to get the so-called nodes, each node is represented as a circle. And then the nodes are propagated down to the heat bed. During propagation, the circles may be enlarged to get better strength and may be moved away from the object so the supports are less likely to collide with the object.
On the support page, we can select 5 types of support, which are variants or combinations of these two types:
normal(auto): normal support with automatically detected overhangs.
tree(auto): tree support with automatically detected overhangs.
hybrid(auto): combination of normal(auto) and tree(auto), that is, when the overhang area is large, use normal(auto), otherwise use tree(auto). After version 1.4.1, we moved hybrid(auto) from type to style. To enable it, please select type=tree(auto) and style=Tree Tybrid. We made this change because we added a new style (tree slim), and possibly we'll add more styles. It's not appropriate to use support types to do this, or we'll have too many support types. But in fact, tree slim, tree strong, and tree hybrid are only different in some parameters. They are all tree support essentially.
normal: generate normal support only on support enforcers.
tree: generate tree supports only on support enforcers.
Both normal and tree supports have different styles to further adjust the final support structure.
Normal support has two styles:
Grid: the support region is expanded and normalized to rectangles. This is the default style of normal support.
Snug: the support region is NOT expanded, but tightly aligned with the overhang areas. This style is useful when the expanded supports have any side effects, such as in the following case.
Tree support has three styles:
Tree Slim: this features an aggressive branch-merging strategy. As a result, a much smaller support volume is generated without sacrificing strength (by automatically increasing the wall count and using smoother branches).
Tree Strong: the old style that is strong, but sometimes difficult to remove.
Tree Hybrid: the current default style, which is the hybrid of tree strong and normal grid. Below the big flat overhang regions, normal grid supports are generated. Otherwise, it will generate the tree strong supports.
The threshold angle is the maximum slope angle that needs support. If a surface's slope angle to the horizon is less than this threshold value, support will be generated when the support type is auto. The larger this angle is, the more supports will be generated. The default threshold angle is 30 degrees. For most materials, this is a safe angle to print without support.
Raft is a type of support, which is used to generate support at the bottom of the model to lift it up. Usually, when printing materials such as ABS that are prone to warping, then you can enable the raft.
The raft contact Z distance represents the distance between the top of the raft layer and the model.
The first layer density means the density of the first layer of the raft and the support.
The first layer expansion can be used to expand the first raft and support layer, improving the bed adhesion.
Support is composed of two parts: base and interface. Interface layers are the layers touching the object. The rest of the support body is the base. Both parts can use different filaments than the object. Default means no filament is specified and the filament printed at the current layer is used, so filament switching time is minimized. Usually, we select specialized support materials such as support W as the support surface material.
Base pattern This is the infill pattern of the support base. There are currently 5 patterns, as shown below.
Rectilinear is the most commonly used support and default pattern for normal support, which usually goes in two directions (left to right, front to back)
Rectilinear grid is similar to rectilinear, except it alternates the direction of every layer, so its strength is much better but can be harder to remove.
Honeycomb is very different than the other two, and is a good balance of strength and stability for taller support structures.
Lightning is an extremely sparse infill pattern for tree support, which can save both material and printing time, but with lower strength.
Hollow is a default pattern for tree support, which means no infill at all.
Base pattern spacing
For rectilinear and rectilinear grid patterns, this is the spacing between base pattern lines.
For the honeycomb pattern, this is the radius of each honeycomb cell. So when this value is set to 0, the honeycomb pattern degenerates to rectilinear.
Pattern angle Set the rotation Angle of the support pattern on the horizontal plane.
Top interface layers The number of top interface layers. The overhang quality can be improved if we increase this value, at the cost of slightly more material.
Interface pattern The line pattern of interface layers. There are currently 3 patterns available:
Rectilinear: rectilinear pattern, suitable for most cases.
Concentric: concentric circular pattern, which is stronger on non-planar surfaces and useful with support materials. For best surface quality we can set a very small interface spacing (e.g. 0) when using cocentric pattern and support material.
Default: kind of auto pattern. The default pattern with support material is rectilinear and concentric with other materials. Support materials may be soluble or not.
Don't Support bridges For normal support, this option controls whether to remove supports for bridges. For tree support, we replace this option with Max bridge length which will be explained later.
Thick bridges If enabled, bridges will be extruded with higher flow, which means bridges are more reliable and can bridge for longer distances. However, the overhang surface quality may be worse because of possible overflow.
Tree support branch distance: the distance between neighboring tree support nodes. Smaller value means higher sampling density on the overhang surface, therefore better surface quality, at the cost of more removal difficulty.
Tree support branch diameter: the initial diameter of tree support node. Larger value means stronger tree supports, also more difficult to remove.
Tree support branch angle: the angle of tree branchs stretch out. Larger value means tree supports have higher ability to avoid objects.
Tree support with infill: infill will be generated in tree support base if enabled. This makes tree support very strong, so we disable it by default. But if you are using some weak material, e.g. silk PLA, it's suggested to enable this option.
Max bridge length: the max allowed bridging length for overhangs. If an overhang is rectanglar, it is regarded as a bridge. A short bridge can be printed well enough without support, because the two ends of the extrusion lines are well supported. The max allowed bridging distance may be different for different materials. When a bridge is larger than max bridge length, it's divided into equal segments and only the contacting points are supported.
For large planar overhang, Normal supports usually give better surface quality than tree supports. That's why we propose hybrid support. So it's safe to choose hybrid(auto) in general, since for these cases hybrid(auto) will degenrate to normal.
For objects with complex structures and most of the overhangs are small, non-planar surfaces, tree or hybrid(auto) supports give stronger support structure, less material, and less time cost, while keeping similar surface quality.