Bottom Z distance
The gap between the part and a support that grows on top of it (when the support starts on a face of the part instead of on the plate). It's like the top distance, but facing down.
How it works
When a support starts on the part instead of on the plate, its first layer would sit on a face of the part and fuse with it. This gap prevents that weld: the support starts one layer higher, in the air, and grips just enough.
With less gap, the support sits more firmly but marks the face; with more, the face stays clean, but the support may start out crooked.
When to change it
- Most parts: the default 0.20 mm.
- A figure with ugly marks on the shoulder or thigh, right where the arm's support starts: 0.25 mm.
- Supports that start on the part and fall over soon after: 0.10–0.15 mm.
Typical values
| Value | What for |
|---|---|
| 0.20 mm | Defaultdefault |
| 0.10 mm | Firmer support; leaves a mark |
| 0.25 mm | Cleaner faces |
Watch out for
- It doesn't apply to support that starts on the plate, or when “On build plate only” is turned on.
- With support filament in the bottom interface, it can be 0.
Goes well with
What Bambu Studio saysits help card, quoted
What Bambu Studio says
The z gap between the bottom support interface and object
Bambu Studio tooltip for this setting · AGPL-3.0
Read more at the official source
In your profile0.20mm Standard @BBL A1 · 0.2 mm · changes with the profile
In Bambu Studio, the profile 0.20mm Standard @BBL A1 sets it to0.2 mm
In other slicers
- Orca Slicer
- Bottom Z distanceSupport › Advanced
- PrusaSlicer
- Bottom contact Z distanceSupport material › Options for support material and raftIn Prusa, 0 doesn't mean no gap: it means using the same distance as on top.
- Cura
- Support Bottom DistanceSupport
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits