The DfAM checklist: 30 checks before you print

Run this before every print that matters — it's the same sequence we use in design reviews with client engineering teams. Five sections, thirty checks, in the order the decisions actually get made.

1 · Process fit

1. Material requirements (temp, chemical, cert) are written down — and the chosen process can print that material.
2. The process was chosen with reasons, not habit (see the selection guide).
3. Quantity justifies additive — you've checked the molding/machining crossover.
4. Part fits the build volume with orientation freedom to spare.
5. Unit cost includes post-processing labor, not just material and machine time.

2 · Geometry

6. Walls are integer multiples of extrusion width (FDM) or above process minimums.
7. Every downward surface is > 45° from vertical, bridged, or chamfered.
8. Side holes over ~10 mm are teardropped or diamonded.
9. Mass is in ribs and box sections, not solid thickness.
10. No trapped volumes (SLA drains, powder-bed escape holes ≥ 3–5 mm).
11. Sharp internal corners are filleted — every one is a crack starter.
12. Text and small features exceed the process detail floor in the printed orientation.

3 · Orientation & strength

13. Primary load path runs in-plane (XY), not across layers (Z).
14. Orientation was chosen for strength and critical surfaces first, supports second.
15. Cosmetic faces don't sit on supports or the build plate (unless that's the plan).
16. Anisotropy is accounted for: Z strength assumed at 40–80% of XY until tested.
17. Snap fits and compliant features flex in-plane, with root fillets.
18. First layer geometry is warp-resistant: no huge solid slabs, corners relieved.

4 · Materials in service

19. Service temperature is below the material's HDT with margin.
20. Creep under sustained load is considered (clamps, threaded joints, springs).
21. UV, moisture, and chemical exposure match the material's real resistance.
22. Fasteners use inserts or through-bolts, not bare printed threads under M6.
23. The exact filament/resin/powder SKU is recorded — "PETG" is not a spec.

5 · Release evidence

24. The 3–5 dimensions that matter carry tolerances the process can hold.
25. Every functional hole has a compensation or post-drill plan.
26. An inspection method exists for each toleranced feature.
27. Print settings that affect strength (orientation, walls, infill, material) are captured in the drawing or MES record.
28. A test coupon or first-article plan exists for the real load case.
29. Post-processing steps are written down and repeatable by someone else.
30. Someone other than the designer can print this part from the package alone.