How to Make Your Own Custom Jigs and Fixtures

Designing custom jigs and fixtures can be easily accomplished with appropriate measuring tools and a manufacturing method that enables complex geometries such as 3D printing. First, design the model in CAD based on CAD designs, caliper measurements, or 3D scans of the parts and equipment. Your resulting design can either be 3D printed, machined, or used as a master from which to create a mold.

There are several ways to optimize your design process for customized jigs and fixtures, including:

• Increasing geometric complexity: 3D printing enables complex features and the addition of numbers, names, dates, and other relevant information at no extra cost.

• Reducing the number of parts: Multi-part jigs and fixtures have traditionally been molded with some degree of difficulty, but can often be 3D printed in one piece, simplifying the workflow. 

• Building datum features into the design: Jigs and fixtures that include an idealized feature, such as a perfect right angle, make the inspection of the finished part easier and more accurate.

• Reinforcing to increase rigidity: Adding reinforcing ribs and fillets provides additional structure without dramatically increasing the cost or build time of the part.

• Adding threaded inserts to improve durability: Add threaded inserts or pockets to 3D printed parts to restrain nuts while a bolt is tightened improves the durability of a 3D printed jig or fixture.

• Making allowances to enable removal of machining debris: Adding grooves, channels, and rounded edges to jigs and fixtures facilitates easy removal of extra material while they’re being used to secure a part during subtractive processes that create debris.

• Considering user experience: Design jigs or fixtures so they can be used with one hand, easily identify placement errors, and hold the part without human support or interaction.

Jigs and fixtures can be made from a wide variety of materials, and are often made in the same materials (and through the same processes) as the workflow they support. Typically, manufacturers machine tooling in metal (though sometimes in POM (Delrin) or other plastics) either in-house or through outsourced vendors. Machining requires expensive equipment and skilled labor for CAM settings and machine operation. Besides, most tools are made of multiple-part assemblies, adding complexity. Outsourcing comes with weeks of lead time and high costs. As a result, producing such tools customized and just-in-time can be challenging. Depending on the forces experienced by the part, however, it is not always necessary to produce these tools in metal.

When choosing a material, consider cost, ease of manufacturing, lead time, and structural needs. Custom jigs and fixtures in a variety of plastic materials can be fabricated through additive manufacturing or through a more traditional process like milling.

Koshi Kagaku Kogyo's automated assembly machines use many jigs and fixtures printed with Fuse 1 SLS 3D printer.

Additive manufactured plastics can have a range of materials properties, from softer durometer rubber-like materials such as Formlabs’ Elastic 50A Resin or Flexible 80A Resin, to stiff and strong materials such as PEEK, Formlabs Rigid 10K Resin or Formlabs SLS materials like Nylon 12 Powder. Specialty materials like ESD Resin offer unique advantages like safely dissipating electrostatic discharge, which is esssential for applications like electronics assembly. 

This range of material options enables manufacturers to adjust their design or material choice based on performance, without rendering a machined or molded aid obsolete. Additively manufactured plastic jigs and fixtures often have much shorter lead times, and can be fabricated in-house in a matter of hours.  

Metal jigs and fixtures should be still used for applications where there are intense high temperatures, very heavy loads, or where the process will remain the same through hundreds or thousands of repetitions — making wear and durability very important. Metal manufacturing aids are more expensive than plastic, often have a lead time of at least two weeks, and are heavier and less ergonomic.

Over the last few years, high-resolution 3D printers have become more affordable, easier to use, and more reliable. As a result, 3D printing technology is now accessible to more businesses, but choosing between the various competing 3D printing solutions can be difficult. Read this technology guide to compare the three most established 3D printing technologies, fused deposition modeling (FDM), stereolithography (SLA), and selective laser sintering (SLS).

3D printed jigs and fixtures are often fabricated with FDM because it is fast, easy to use, and low cost. However, SLA and SLS are better suited for manufacturing aids that require:

• Higher resolution, better accuracy, and a smoother surface finish

• Superior mechanical characteristics, such as strength and durability

• Complex designs

• Higher throughput

The following table summarizes some key considerations to choose between SLA or SLS for 3D printing manufacturing aids. Check out Formlabs’ in-depth technology comparison for more details.

3D printers can be purchased and brought in-house with relatively low overhead costs or footprint requirements. Desktop 3D printers like the Formlabs Form 3+ cost as low as $2500, and enable a wide range of material properties. Benchtop machines like the Formlabs Form 3L SLA 3D printer, or industrial power laser sintering technologies like the Fuse Series SLS 3D printer are also accessibly priced and don’t require the complex infrastructure systems of many traditional large 3D printers.

Having these technologies in-house means that employees responsible for one process, such as thermoforming or painting, can easily access the 3D printing technology to produce a custom jig or fixture. The whole process can take less than a day, reducing downtime and making almost immediate improvements to workflow. The manufacturer controls more of the elements involved in production and can easily pinpoint any areas where a customized jig or fixture could immediately make a positive impact on the workflow.

3D printing is a good solution for creating jigs and fixtures to reduce instances of damaged goods or equipment. Traditional workholding systems like vises and clamps can’t secure and support amorphous shapes or parts with very fine details. If they’re used, they can cause damage by virtue of a poor fit or forced attachment. For example, locating fixtures that are 3D printed in a softer durometer material might reduce jarring from the assembly process compared to rigid fixtures made from a milled plastic or metal block.

Automotive supplier Pankl Racing Systems specializes in developing engine and drivetrain components for racing cars, high-performance vehicles, and aerospace applications. They introduced SLA 3D printing in-house to produce custom jigs and other tooling. 

For one particular order, they had to manufacture motorcycle gearbox assemblies through multiple stages of steel machining using automatic lathes. Each stage of turning in the automatic lathes requires custom jigs for every individual gear type. They were looking at a six-week lead time to outsource the jigs. By 3D printing them in-house with the Formlabs SLA printers, they decreased lead time by 90 percent and costs by 80-90 percent, leading to €150,000 in savings.

Thermoforming is a manufacturing process that heats and molds sheets of plastic into a desired shape under vacuum, pressure, or mechanical forces. For one job at Productive Plastics, the machine clamp frame was bigger than the mold, meaning had to stop to wait for a customized spacing fixture, or an unnecessarily large plastic sheet would have to be used, adding to costs. Productive Plastics used in-house 3D printing to fabricate a customized fixture that corrected the spacing between the mold and the frame. 

In-house fabrication of 3D printed jigs and fixtures can reduce downtime by shortening the distance between the issue and the solution. Employees familiar with the manufacturing flow can identify issues before they arise, and design jigs and fixtures to streamline processes before problems come up. By easily communicating with their colleagues, they can identify pain points and design jigs and fixtures within 24 hours that make processes safer, more efficient, or more precise. 

Comparatively, outsourcing jigs and fixtures is inherently reactive — and a customized manufacturing aid that solves a problem after it arises may cause days or weeks of downtime.