Printed Jigs and Fixtures: Where They Pay Off in Production

Most shop floor tooling is a single piece that will be revised at least once. A machined fixture ties up programming, work holding and machine time for something that changes after the first shift. That is the reason printed jigs and fixtures spread through production long before printed end-use parts did.

Where printed fixtures work and where they do not

Printed tooling is reliable for locating, holding, guiding and checking. It is a poor choice where chips and coolant meet impact loads, where a surface slides under high pressure without a wear insert, or where the fixture sits permanently above the material's heat deflection temperature. Everything in between is a question of material and wall design, not of the process.

• Assembly aids that make a manual step repeatable and reduce scrap in final assembly
• Inspection nests that hold a part identically for a dial gauge, camera or visual check
• Go/no-go gauges that replace a slow measurement with a two second check
• Gripper jaws with contoured pads that hold delicate parts without marking them
• Drill and routing templates with pressed steel bushings to guide the tool

Material choice for tooling is about stiffness, not strength

A fixture rarely fails because it breaks. It fails because it deflects, warps or creeps, and the part it locates ends up a few tenths out of position. That makes stiffness and dimensional stability the deciding properties. PA12-CF is our default because it is stiff, dimensionally stable and wear resistant. PC is the answer when the fixture sees heat, for example next to an oven or a heat staking station. ASA holds up outdoors and under UV. Plain ABS is fine for light assembly aids where cost matters more than rigidity.

Design rules that keep a fixture usable

• Put threaded inserts wherever a screw is removed more than a handful of times
• Use pressed steel or brass bushings at drill guides and pivot points, not printed holes
• Give locating faces a defined clearance, typically 0.1 to 0.2 mm, and mark which faces are datum surfaces
• Rib the underside instead of thickening walls, so the fixture stays stiff without long print times
• Print with the load acting across layers where possible, because layer adhesion is the weak axis
• Add a visible engraved part number and revision, otherwise two similar fixtures get mixed up on the bench

What a fixture actually costs

The interesting number is not the price of the first fixture but the price of the second revision. Machining a revised fixture repeats programming and setup. Printing a revised fixture costs material and machine time again, nothing else. Teams that treat tooling as consumable rather than as an investment usually end up with better fixtures, because nobody defends a bad design to protect a sunk cost.

Send us the STEP file of the workpiece, not only of the fixture. Most of the fixture geometry follows from the part it has to hold, and we can flag clearance and access problems before anything is printed.