Chamfer the underside of tabs, clips & overhangs
That little tab sticking out of your part is a support magnet. Angle its underside instead of leaving it flat and you delete the supports, the cost, and the ugly scar.
Applies to
- Process
- FDM / filament
- Features
- Tabs, clips, snap fingers, mounting ears
- Orientation
- Feature printed horizontally off a wall
- Goal
- No slicer supports under the feature
Why it matters
A flat tab prints into thin air, so the slicer props it up with support material. That adds print time, adds cost, and leaves a rough, nasty underside once you pick the support off.
A chamfer turns the overhang into a self-supporting slope. You barely add material, the feature gets more durable than the thin flat tab ever was, and it still slots or clips exactly where it needs to.
What good looks like
- The underside of the tab ramps back into the part instead of ending flat
- Corners are rounded so the nozzle flows cleanly onto the feature
- The part slices with zero support under the tab
How to apply it
- Find every feature that overhangs into open air (tabs, clips, hooks).
- Add a chamfer from the part body down to the tip of the feature, steep enough to self-support (start near 45°).
- Round the corners and the bottom edge so the surface flows and stays clean.
- Re-slice and confirm supports are gone under the feature.
Exceptions & tradeoffs
A clip still needs to flex — after chamfering, tweak the geometry so the fingers deflect the right amount and don’t become too stiff.
Common mistakes
- Leaving a flat tab and letting the slicer support itChamfer the underside so it self-supports
- Sharp inside corners where the tab meets the bodyFillet them so material flows and the joint is stronger
Chamfering tab/clip undersides to eliminate supports and improve durability — Better Horizontal Mounting Features | Design for Mass Production 3D Printing ↗.
Summarized and independently edited by Start Here. Starting values and cautions are our editorial notes, not a quotation from the creator.