Academy Guide

Design for Additive Manufacturing (DFAM)

Additive manufacturing constructs models layer by layer from the ground up. This differs radically from traditional subtractive manufacturing (CNC milling) or injection molding. Understanding **DFAM** principles ensures high structural stability, precise fits, flawless surfaces, and minimal printing costs.

Layer Orientation

Prints are weaker along the Z-axis (layer lines). Align high-stress directions horizontally (X-Y plane).

Overhang Angle

Slopes exceeding 45° require support pillars. Designing self-supporting slopes saves print time and clean-up.

Volume & Density

Hollow models or models utilizing optimized infills reduce material consumption, mass, and warping stress.

Core DFAM Principles

Always add bottom chamfers: First layers tend to squish slightly (known as elephant foot). A 45-degree chamfer of 0.5mm mitigates dimension errors.
Utilize standard nozzle baselines: FDM shells print in loops of 0.4mm. Keep structural walls at multiples (0.8mm, 1.2mm, 1.6mm) for rigid, seamless shells.
Incorporate escape holes: Resin prints are hollowed to save weight. Always design escape holes (min 2mm diameter) to rinse uncured liquid resin from inside the cavity.

Spec Sheets

Filament & Resin Parameters

Choosing the correct material affects the physical capabilities of your end-use parts. Check below for our active material thresholds:

PLA Filament

PLA is the easiest to print. High stiffness, low warping, excellent detailed finishing. Best suited for aesthetic mockups, prototypes, and architecture.

Max Tensile Strength

60 MPa

Heat Deflection Temp (HDT)

52°C

Elongation at Break

5.2%

Print Density

1.24 g/cm³

Design Constraints

Standard Clearance & Geometry Rules

Follow these geometric standards closely to guarantee operational threads, hinge joints, and solid structures:

Moving Interlocking Clearance (Hinges, Gears)

Design files must separate adjacent parts by at least **0.25mm to 0.40mm** for FDM assemblies. For high-resolution SLA resin, keep clearances to a minimum of **0.15mm**. Overlapping shapes will fuse together permanently.

Wall Thickness Tolerance

FDM parts require structural walls to be at least **0.8mm** (2 loop passes). SLA parts require a minimum of **0.6mm** wall thickness to prevent thin walls from bending or splitting during the curing bath phase.

Horizontal Overhangs & Bridges

Unsupported bridges extending past **8mm** will sag under gravity. Overhang angles steeper than **45°** require physical support lattices, leaving minor texture anomalies when removed.

Mold Draft Angles (Injection Molding)

All vertical surfaces in injection molding require a draft angle of **1° to 2°** relative to the draw direction. Without draft angles, parts will friction-lock and fail to release cleanly from the steel mold cavity.

Tolerances

Fitting Tolerances & Fasteners

For slide locks, threaded connections, or press fits, choose the recommended offsets:

Fit Type	Description	FDM Filament Offset	SLA Resin Offset
Press Fit (Hammer/Tight)	Fixed connection. Pieces wedge firmly.	+0.05 mm	+0.02 mm
Snug Friction Fit	Removable cap/lid. Holds by friction.	-0.10 mm	-0.05 mm
Sliding / Pivot Fit	Hinge, pin joint, slider. Needs clear space.	-0.25 mm	-0.15 mm
Free Rotational Fit	Freewheeling axle, rolling gears.	-0.40 mm	-0.25 mm

Offset Fit Recommendation Helper

Input your nominal target pin/hole diameter, and choose your desired fit to estimate cut dimensions:

Nominal Size (mm)

Desired Fit

Estimated Cut Hole Diameter

9.90 mm