Bridge counterbore holes
A counterbore hole has two widths: a wide one where the screw head hides and a narrow one for the threaded part. This option decides whether a bridge is laid over the step between them so you don't need supports.
How it works
When the wide part of the hole is at the bottom (for example, because the face where the screw goes in is the one sitting on the plate), the first layer of the step hangs in the air as a ring. Without help, those strands droop and the screw seat comes out ugly.
“Partially bridged” lays strands only over the unsupported ring and leaves the center hole open: it comes out flat and there's nothing to remove. “Sacrificial layer” closes the whole hole with a very clean bridge layer, which you then have to poke through to fit the screw.
When to change it
- A box lid with hidden-head screws, printed without supports: “Partially bridged”.
- A wall bracket whose screw seat has to be perfect, and you don't mind drilling it afterward: “Sacrificial layer”.
- Narrow steps (1–2 mm) or parts that already have supports: “None”.
Typical values
| Value | What for |
|---|---|
| None | Default; the step is printed in mid-airdefault |
| Partially bridged | Strands only where needed |
| Sacrificial layer | Closes the hole; drill it afterward |
Watch out for
- It only recognizes round holes with a step; it does nothing on slots or odd shapes.
- With “Sacrificial layer”, remember to drill through it: the hole is left covered.
Goes well with
What Bambu Studio saysits help card, quoted
What Bambu Studio says
This option creates bridges for counterbore holes, allowing them to be printed without support. Available modes include: 1. None: No bridge is created 2. Partially Bridged: Only a part of the unsupported area will be bridged 3. Sacrificial Layer: A full sacrificial bridge layer is created
Bambu Studio tooltip for this setting · AGPL-3.0
Read more at the official source
In your profile0.20mm Standard @BBL A1 · None
In Bambu Studio, the profile 0.20mm Standard @BBL A1 sets it toNone
In other slicers
- Orca Slicer
- Bridge counterbore holesQuality › Bridging
- PrusaSlicer
- No clear equivalent.
- Cura
- No clear equivalent.
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits