3D printed tooling: moulds, jigs and fixtures.

Why 3D printing for manufacturing tools?

Moulds, patterns, jigs and fixtures are often one-off or low-volume parts that are large and revised whenever the product changes. Produced by machining or by hand, they require long preparation and a high labour content. Large-format 3D printing produces the tool directly from the digital model:

• Design changes are implemented by updating the digital file and printing again.
• Managing infill and wall thickness reduces the weight of the tool and improves operator ergonomics.
• A replacement tool can be reprinted from a digital archive instead of being held as physical stock.
• Tools up to 2 metres produced as a single body eliminate joint-related deviation and labour.

Where a tool is intended for high-volume, long-life series production, metal tooling is usually the better choice. 3D printing delivers most value in prototype and pre-series phases, in low- and medium-volume production and in frequently changing product ranges.

Thermoforming and vacuum-forming moulds

In vacuum forming, a plastic sheet is heated and drawn over the mould. In 3D printed moulds, vacuum holes and channels can be added to the model at the design stage. The mould material must hold its shape at the temperature at which it contacts the heated sheet; instead of materials with low heat resistance, ABS, ASA, PC or higher-temperature polymers are chosen according to quantity and temperature. Because the mould surface is transferred directly to the sheet, layer lines are removed by sanding or coating where surface requirements are high.

Casting patterns and master models

Sand-casting patterns, core box parts, master models for silicone moulds and investment-casting patterns can be produced by 3D printing. A sand-casting pattern must withstand sand ramming forces and abrasion and must not be affected by release agents and binders. Shrinkage allowance and draft angles should be built into the model, and the pattern surface should be finished and sealed so that it releases cleanly from the mould.

Composite lay-up moulds

Large, single-body lay-up moulds can be printed for composite parts used in marine, aerospace and automotive applications. The higher the cure temperature, the higher the heat resistance the mould material needs: engineering materials may suffice for room-temperature-cure resins, while high-performance polymers such as PEI (ULTEM) or PEEK are considered for high-temperature cure. For vacuum bagging, the surface must be sealed with a coating, and the difference in thermal expansion between mould and composite must be considered in the design.

Jigs, fixtures and gauges

Assembly fixtures, welding and bonding jigs, inspection and measurement (CMM) fixtures, go/no-go gauges, robot grippers and machine guards are the tools most often printed for the production line. Contact surfaces that match the part exactly, low weight and fast revision are the main benefits. Fibre-filled materials (e.g. PA-CF) suit fixtures that need stiffness, and polymers with higher temperature resistance suit welding jigs exposed to heat.

Design rules for printed tooling

• Walls and infill: Thicken walls where the tool carries load and keep infill low elsewhere to reduce weight and print time.
• Metal inserts: Use heat-set threaded inserts, bushings and dowel pins for frequently disassembled connections.
• Datum surfaces: Leave a machining allowance on surfaces that need precise dimensions and finish them by machining.
• Print orientation: Choose it considering both the load direction and the surface quality required; interlayer strength is lower than in-layer strength.
• Large tools: Tools that fit the working volume are printed as a single body; larger ones are designed in sections with alignment pins and fasteners.

Material selection by tool type

For the general properties of these materials, see the 3D printing materials guide.

Tooling production on the BPT 2010

Build volume

2000 × 1000 × 1000 mm; tools up to 2 metres as a single body

Print speed

Up to 1000 mm/s (2000 mm/s travel)

Materials

PLA, ABS, ASA, PA, PC; PEEK, PEKK, PPS, PPSU, ULTEM / PEI

Fibre-filled

Carbon / glass fibre-filled materials (e.g. PA-CF), with a wear-resistant nozzle

Extruder

Independent dual extruder; model and support from separate heads

Position control

1 µm resolution, closed-loop feedback

Frequently asked questions about 3D printed tooling

How long does a 3D printed mould last?

Service life depends on the material, operating temperature, pressure and quantity. 3D printed moulds are widely used for prototypes and low-volume production; validating the mould with initial trials for the expected quantity is recommended.

How are vacuum holes made in a thermoforming mould?

Vacuum holes and channels are added to the 3D model at the design stage and, where necessary, completed by drilling after printing.

Which material suits a sand-casting pattern?

PLA, ABS or PC, with good dimensional stability and machinability, are common choices. The pattern surface should be finished and sealed so that it releases easily from the mould.

Can 3D printed fixtures replace metal fixtures?

Loads are low on most assembly and inspection fixtures; in these applications lightweight, part-specific printed fixtures provide sufficient strength. Metal inserts or fibre-filled materials are used in areas of high load or wear.

Can I print a large mould without splitting it?

The build volume of the BPT 2010 is 2000 × 1000 × 1000 mm; moulds that fit this volume are printed as a single body. Larger moulds can be designed in sections with alignment features.