Dimensions out of tolerance
Holes come out undersized, outer walls oversized, and parts do not fit as designed.
Needs tuning dimensions tolerance too small shrinkage holes too tight
Likely causes
- Thermal shrinkage of the material
- Over-extrusion
- Hole compensation not set
- Belt backlash
How to fix it
- Calibrate flow first, then apply a scale factor per material (PLA ~100%, ABS ~100.8%, nylon ~101%).
- Enable hole compensation / "XY hole compensation" of ~0.05–0.15 mm.
- Design clearance into mating parts: 0.2–0.3 mm for FDM.
- Check belt tension to remove backlash.
Work through it in order
The fastest path to a fix
Change one thing at a time and print a small test. Start with the first fix listed — it is the most common cause.