Drilling 3D printed holes to final size
For functional parts, it can be useful to print a hole slightly undersized and drill it to its final dimension afterwards. This is especially practical for screws, shafts or cylindrical interfaces that need more repeatable sizing than the raw print provides. The part must contain enough material around the hole to survive machining.
When drilling is useful
- screw clearance holes
- shafts
- locating pins
- mounting holes
- insert test parts
Do not drill every thin feature
Thin printed walls can:
- crack
- chip
- twist
- deform if there isn't enough surrounding wall material — design for it
Drilling plastic
General approach — exact speed depends on tool and polymer:
- secure the part
- centre the tool
- avoid excessive speed
- limit heat buildup
- clear chips
Design for post-processing
If a hole will be drilled, intentionally leave appropriate material for finishing.