1. Parts Don't Fit Together - Troubleshooting Guide
If your 3D printed parts don't fit together as expected, several factors could be at play:
2. Common Causes
1. Insufficient Clearance in Design — Parts designed with zero or tight clearance won't account for 3D printing tolerances.
Solution: Add 0.2-0.4mm clearance for FDM, 0.1-0.2mm for SLA in mating features.
2. Material Shrinkage — Some materials shrink slightly after printing as they cool. Nylon and ABS shrink more than PLA or PETG.
Solution: Design with material-specific shrinkage compensation or use low-shrink materials.
3. Dimensional Tolerance Variations — 3D printing has inherent tolerances (±0.1-0.5mm depending on technology). Tight-fitting assemblies may fall outside tolerance.
Solution: Test fit with prototypes, adjust clearances as needed.
4. Support Removal Artifacts — Support material on mating surfaces can prevent proper fit.
Solution: Clean support residue thoroughly; sand mating surfaces smooth.
5. Warping or Deformation — Large parts may warp slightly during printing or cooling. Thin walls may deflect.
Solution: Reinforce thin sections, add ribs, use low-warp materials.
6. Incorrect Scaling — File may have been exported or uploaded with wrong units.
Solution: Verify dimensions match your CAD file; resubmit with correct scaling.
3. How to Fix It
Immediate Fixes:
Sand or file mating surfaces lightly to increase clearance
Heat and reshape (for some materials) using a heat gun carefully
Drill out holes that are too tight
For Reprints:
Increase clearances in your CAD model
Specify critical dimensions and tolerances when ordering
Order a test fit sample before committing to quantity
4. Prevention for Future Orders
- Design with 3D printing tolerances in mind
- Order samples to test fit before production
- Communicate critical fit requirements with our team during quoting
👉 If your parts don't fit due to our error or quality issue, submit a support ticket for a reprint.