Why DFM Matters

Design for Manufacturability is the discipline of making design decisions that reduce production cost, improve yield, and prevent rework. Engineers who apply DFM principles consistently report fewer order revisions, lower per-unit costs, and faster iteration cycles.

This checklist covers the most common DFM issues across all three of our core services: 3D printing, PCB production, and laser/CNC cutting. Run through it before every submission.

Wall Thickness Rules

Walls that are too thin crack during printing or handling; walls that are too thick waste material and slow print time.

  • FDM 3D printing: Minimum 1.2mm for structural walls (2× nozzle diameter as a baseline)
  • Resin 3D printing: Minimum 0.8mm for solid walls; 1.5mm+ recommended for loadbearing features
  • Laser-cut acrylic: Minimum slot/feature width = 1× material thickness
  • Laser-cut MDF: Minimum slot width = 1.5× material thickness for reliable cutting
  • CNC aluminum: Minimum wall width = 1mm for 3mm thickness, scale up for thicker stock

Hole and Gap Tolerances

If parts need to mate or fit together, tolerance planning is critical. FDM parts shrink slightly during cooling and may need to be slightly oversized for press fits.

  • Clearance fit (loose): add 0.3–0.5mm to the nominal hole diameter for FDM
  • Interference/press fit: use nominal dimension or add 0.1mm max for FDM
  • Laser cutting: slots and tabs should match the material kerf width (test-cut at 0mm offset first)
  • PCB drills: add 0.1–0.2mm to component lead diameter for easy insertion

Support Structure Planning

Minimize supports in 3D printing wherever possible. Supports increase print time, waste material, and leave witness marks on the supported surface.

  • Design overhangs to be ≤45° from vertical to avoid support generation
  • Orient parts so the critical surface faces upward (resin) or away from support contact
  • Use chamfers instead of sharp horizontal overhangs on FDM parts
  • Add self-supporting bridging where possible; FDM can bridge up to ~60mm reliably

Surface Finish and Orientation

Part orientation in the slicer directly determines which surfaces get layer lines. The bottom face of an FDM print will be the smoothest; the top face will show visible steps. Plan orientation around which surfaces matter most cosmetically.

For resin prints, the bottom (print-start) surface has the worst finish due to the first-layer compression. Orient cosmetically critical faces away from the build plate.

Tip: Including an orientation preference note with your order helps our production team align quality with your actual priorities.

File Format Checklist

  • 3D Printing: STL (most common), STEP, OBJ. Ensure the mesh is watertight (no open shells). Check in a slicer preview before uploading.
  • PCB: Gerber RS-274X + Excellon drill file for bare boards. Add BOM in CSV for assembly orders.
  • Laser cutting: DXF or SVG with all geometry as closed vector paths. No raster art on cut layers.
  • CNC routing: STEP or IGES for 3D operations. DXF works for 2.5D (contour and pocket) operations.

Final Pre-Submission Review

Before you upload, confirm:

  • File is exported in the correct format and opens without errors in a viewer
  • Units are correct (mm, not inches; verify in your slicer/DXF importer)
  • No duplicate geometry, self-intersecting faces, or zero-thickness features
  • Material, quantity, and finish are specified clearly in your order configuration
  • Tolerances for mating parts have been checked against the process capabilities
  • DRC has passed with zero errors (PCB orders)