Some of the screws will be flush mount, flat head machine screws. How do I model this in fusion 360?
That’s a countersink, and Fusion handles it cleanly. Here’s the no-nonsense way.
Correct way (Hole tool – recommended)
- Create → Hole
- Placement: click the sketch point / hole center
- Type: Countersink
- Hole Diameter: your clearance (e.g. 6.7 mm)
- Countersink Angle: 82° (most inch flat-head screws)(Metric flat heads are often 90° — check the screw)
- Countersink Diameter: set so the head sits flush→ usually ~12–13 mm for 1/4” flat head
- Extent: Through All
- OK
Alternative (manual, more control)
Use this if you already have holes:
- Extrude the hole normally
- Modify → Chamfer
- Select the top edge of the hole
- Type: Angle–Distance
- Angle: 82°
- Distance: tweak until flush
Good for fine tuning or weird screws.
Sizing cheat sheet (1/4" flat head)
- Clearance hole: 6.6–6.8 mm
- Countersink angle: 82°
- Countersink diameter: 12–13 mm
- Add +0.2 mm if printing PETG
Pro 3D-printing tips
- Countersinks print better if the part is face-up
- Add 0.2–0.3 mm extra depth so the head truly sits flush
- Slight elephant’s foot? Add a 0.3 mm chamfer on the bottom too
Parametric win
Add parameters:
- cs_angle = 82 deg
- cs_clearance_1_4 = 6.7 mm
- cs_head_1_4 = 12.5 mm
If you want, tell me:
- PLA or PETG
- Screw brand (McMaster, Amazon, unknown)
- Face-up or face-down print
I’ll dial the numbers so they land flush on the first print.