Spare parts and replacement parts are crucial components for both manufacturing plants and general users, as they help reduce equipment downtime and minimize the impact on operational efficiency when equipment is damaged and requires repair or refurbishment.
To access and supply these critical spare parts, companies need to maintain costly inventories and manage them across complex and constantly evolving supply chains.
But what happens if a supplier goes out of business, or if the lead time for production and delivery takes too long?
The use of 3D printing technology for the production of spare parts and replacement components is becoming a highly promising approach to addressing supply chain uncertainty and the current shortage of spare parts.
Today, 3D printers can be used to create a wide variety of parts, ranging from...
DIY spare parts
Temporary replacement parts (stopgap replacement parts)
This extends to durable and long-lasting replacement parts that can replace parts originally manufactured using traditional processes.
This approach allows manufacturers to reduce the need to keep large inventories of spare parts and switch to on-demand spare part production instead.
This guide describes the steps involved in creating and manufacturing digital replacement parts using additive manufacturing, including advice on selecting the right technology and providing real-world application examples across various industries.
Step-by-step process: 3D printing spare parts and replacement components.
1. Check for feasibility.
Spare parts are components that work together within a system. Therefore, to ensure that 3D printed parts function correctly, the first step should be to consider the technical specifications of the part, such as geometry, intended application, and the mechanical forces the part will withstand. Let's look at some important criteria:
Geometry (shape):
3D printers offer almost unlimited design freedom, so it's highly likely that any part produced with traditional tools can also be manufactured using 3D printing. However, minor design modifications may be necessary to help lower costs, speed up printing, or increase part strength.
Size:
The part must be sized to fit into the build volume of the 3D printer, which typically has a build volume of 15–30 centimeters in each dimension for desktop or benchtop printers. If the part is too large, an alternative design may be created by assembling multiple smaller parts.
Material:
3D printers can replace most plastic parts, and even some types of metal parts. The material chosen should be as close as possible to the properties of the original part.
Stresses (forces and loads that a part must withstand):
Consider the compressive, tensile, impact, or other loads that the replacement part will face. Opt for more advanced 3D printing technologies and engineering materials if a long lifespan for the part is desired.
Although 3D printed parts may not meet all requirements, in many cases they can be used as temporary stopgap replacements to reduce machine downtime.
In such situations, 3D-printed parts are used to keep the machinery functioning normally, although long-term durability may be limited. These parts are used until more durable replacements become available.
2. Obtain the 3D model.
Once it's confirmed that a part is 3D printable, the next step is to obtain a 3D model of that part.
If the replacement part is a product of your company and was previously designed using CAD software, the digital files of that part are usually already available.
For third-party tools or equipment, some manufacturers may release the original CAD files of the parts for use.
If no design template exists, you can create a new one yourself using CAD software or hire a professional design service.
For parts with simple shapes, modeling can be done by taking manual measurements and then creating a model in CAD.
However, for parts with more complex shapes, reverse engineering combined with 3D scanning is a highly efficient process for designing and manufacturing recreated parts that are as close to the original as possible.
Reverse engineering is the process of using a 3D scanner to collect surface information of an object and create a mesh, which is a three-dimensional data structure necessary for building 3D models.
3. Print spare parts using 3D printing.
Prepare your CAD model for 3D printing using print preparation software, then send the file to your 3D printer.
Choosing the right printing technology and materials is very important, and the next section will provide specific advice on this.
Generally, 3D printed parts usually require some form of post-processing, such as:
Washing the workpiece.
Removal of remaining powder material (depowdering)
Removing support structures
Post-curing is an additional heat treatment process that increases the material's strength.
Exfoliation (sanding)
After that, the parts can be used directly, or they may undergo further finishing processes depending on the application, such as:
Smoothing the surface
Painting
Coating
Or other customization processes.
4. Testing and Iteration
Once replacement parts are available, testing should be performed to ensure that the 3D-printed parts function as designed.
If test results show that the part still has defects, 3D printing technology allows for rapid design modification and reprinting to improve the performance of the replacement part.
The intensity of the testing should depend on the application of the component.
In the case of temporary replacement parts (stopgap replacement parts), it may be sufficient if they can simply function for a limited time.
However, for manufacturers who intend to use 3D-printed parts as permanent replacements for traditionally manufactured parts, the new parts should undergo the same testing process as the original parts.
Furthermore, the specific characteristics of the 3D printing process should also be considered, such as the strength of the part, which may vary depending on the printing orientation. This is a crucial factor that can affect the performance and long-term durability of the part.
Selecting the right technology and materials for 3D printing replacement parts.
3D printing technology has been widely used in prototyping and product development for several decades.
Currently, this continuously evolving technology is beginning to be widely used in real-world industrial manufacturing processes.
In the product development process, many manufacturers have leveraged the flexibility of 3D printing to produce in-house tools such as:
Jigs
fixtures
Various types of manufacturing aids.
This includes the production of tools for rapid manufacturing (rapid tooling), such as:
Molds for plastic injection molding
Molds for the thermoforming process.
Recent advances in machinery, materials, and software have created new opportunities for the production of high-precision, practical, and industrial-scale 3D printed parts.
Printed parts can therefore be used to replace more end-use parts, including:
Durable spare parts.
Replacement parts that are designed for long-term use.
3D printers are most commonly used to produce parts made from plastic, although 3D printers for metal are also available, but they are generally significantly more expensive.
There are many types of 3D printers available today, with the most widely used processes for producing plastic parts including:
Fused Deposition Modeling (FDM)
Stereolithography (SLA)
Selective Laser Sintering (SLS) The following is a brief comparison of these processes, including the materials that can be used and their appropriate applications, particularly in the context of spare parts manufacturing.
| Fused Deposition Modeling (FDM) | Stereolithography (SLA) | Selective Laser Sintering (SLS) | |
|---|---|---|---|
| Accuracy | ★★★★☆ | ★★★★★ | ★★★★★ |
| Surface Finish (Quality of the workpiece surface) | ★★☆☆☆ | ★★★★★ | ★★★★☆ |
| Throughput (Production volume / Production speed) | ★★★☆☆ | ★★★★☆ | ★★★★★ |
| Complex Designs (Supports complex design work) | ★★★☆☆ | ★★★★☆ | ★★★★★ |
| Ease of Use | ★★★★★ | ★★★★★ | ★★★★☆ |
| Materials (available materials) | Standard thermoplastics such as ABS, PLA, and various composite materials. | A wide variety of resins, including engineering materials with advanced properties such as ABS-like, PP-like, flexible, heat-resistant, and rigid. | Engineering-grade thermoplastics such as Nylon 11, Nylon 12, and composite materials, including TPU, are used for parts requiring flexibility. |
| Ideal for | Simple replacement parts | ||
| Temporary solutions (stopgap solutions) | Both simple and complex replacement parts. | ||
| Temporary solution | |||
| Parts requiring high detail and a smooth surface finish. | Both simple and complex replacement parts. | ||
| Temporary solution | |||
| Replacement parts for practical use that are strong, stable, and long-lasting. |
While most traditional manufacturing processes require expensive industrial machinery, specialized production facilities, and highly skilled operators, 3D printing enables in-house part production with lower operating costs and minimal infrastructure requirements.
Compact, desktop or benchtop 3D printing systems used for producing plastic parts are affordable, require minimal space, and don't require highly specialized skills to operate.
Outsourcing can be an option for non-urgent replacement parts; however, this method often comes with challenges similar to traditional spare parts inventory management.
Delivery times can take several weeks, while 3D printing for most parts can be completed in less than 24 hours. Waiting for external parts risks prolonged machine downtime and potential loss of production efficiency.
Producing spare parts using digital fabrication.
For manufacturers, digitizing spare parts inventory management and replacement parts production systems opens up opportunities to reduce or eliminate many traditional problems, such as:
Supply chain issues
Minimum order quantities
And losses resulting from obsolete or unused parts.
Creating a digital warehouse is a cost-effective way to reduce inventory management costs.
When this system is integrated with in-house digital manufacturing tools, such as 3D printing, it can support an on-demand manufacturing approach.
This approach allows manufacturers to...
Reduce costs and production lead time.
Increase resilience and the ability to cope with problems.
And it reduces the time the machinery has to be down (downtime).
A digital data warehouse, or digital spare parts warehouse, will be used for...
Store the design files of the spare parts.
Categorize the parts systematically.
Improve and manage the bill of materials to make it more efficient.
This includes managing inventory data.
Then, 3D printers and other digital manufacturing tools can be used to produce those parts, either to replenish physical inventory or to manufacture immediate replacements when needed.
Case Study: How Companies Use 3D Printing to Produce Replacement Parts
Replacement parts are one of the most common applications for 3D printing. Let's look at some real-world examples from Formlabs customers, from printing automotive parts to creating custom-made robot grippers.
The award-winning custom car shop Ringbrothers initially adopted SLA (Stereolithography) 3D printing technology in-house as a prototyping tool, enabling faster and more cost-effective modifications and development of parts.
After implementing this technology, they discovered new ways to use 3D printing to enhance the quality and creativity of their work, enabling the production of end-use parts, including replacement parts for classic cars.
For the mirror project, the team used 3D-printed components as part of the final assembly structure. These components served as permanent assembly fixtures, secured within a carbon shell, with other parts screwed onto them.
In another case, the team used castable 3D printing material to print prototypes before casting them into metal emblems for a bespoke car project.
Matt Moseman, a product development expert, said that:
"Such a high level of detail would be impossible if we couldn't 3D print a wax prototype and have a local jeweler cast the piece in-store."
Another example is Ashley Furniture, the world's largest furniture manufacturer, which has incorporated new technologies into its factories, from 3D printing to robotic automation.
Inside Ashley Furniture's factory in Arcadia, Wisconsin, up to 700 3D-printed parts are used on the production line, working in conjunction with other industrial machinery such as industrial robots and CNC milling machines, from assembly to the manufacturing of various parts in the factory.
Besides its use as a manufacturing aid, another highly useful application is in producing replacement parts for machinery on a production line (manufacturing floor).
In one case, the vacuum retainer ring for a point-to-point drilling machine could not be purchased separately; the manufacturer only sold the complete assembly, which was quite expensive.
"The manufacturer doesn't sell just the ring; we have to buy the whole assembly kit for $700."
Brian Konkel, a production engineer, said:
“But ultimately, we opted to 3D scan the part to capture its geometric shape and then 3D print the replacement part for just $1, allowing our drilling machine to continue functioning without needing to purchase a whole new assembly.”
Instead of having to buy a whole new assembly for $700, the company chose to use 3D printing to produce only the replacement parts at a cost of just $1.
Productive Plastics is a leading contract manufacturing company specializing in the production and design of custom plastic thermoforming parts.
The company's factory has a total of six manufacturing cells, enabling it to handle multiple projects simultaneously.
Each production cell consists of:
industrial thermoformer
CNC milling machine
Assembly area
A computer system for managing and monitoring operations.
When the cooling fan of one of the machines is damaged, the thermoformer becomes unusable, causing the entire cell production process to shut down.
The team was aware that ordering replacement parts from suppliers would take 6–8 weeks to receive.
To keep the production line running while awaiting repairs, the team opted for 3D printing to produce temporary replacement parts for the impeller.
The team designed two versions of the replacement propeller in SolidWorks and then printed them using a Fuse 1 SLS 3D printer with Nylon 12 Powder material, which took only one night.
Because the SLS 3D printing process is self-supporting, it allows for the creation of dual-sided designs with a center bore.
Furthermore, there is no need to spend time removing support structures or performing additional post-printing processes, allowing the finished propellers to be immediately installed onto existing machinery.
A 3D file of an impeller component for use as a temporary replacement part (stopgap replacement part) created in SolidWorks.
Kyle Davidson, Director of Sales and Marketing at Productive Plastics, said:
"If other printing methods are used, it will be difficult to create the back of the propeller, especially the rib and center bore, which have the same structural characteristics as parts produced by injection molding."
One of the reasons we chose Fuse 1 is because we don't need any supports for printing.
This piece is a very clear example demonstrating Fuse 1's ability to print objects with complex geometric shapes.”
A close-up (right) and a magnified (left) view of a 3D-printed impeller that fits perfectly onto a vacuum pump of an industrial thermoforming machine.
The 3D-printed propeller was immediately usable, allowing the production cell to get back online the day after the machine malfunctioned. The part continued to function normally until the team switched back to using parts from a supplier approximately six weeks later.
At Productive Plastics, the cycle time of a production cell is approximately 5–15 minutes, meaning that one production cell can produce at least 40 items per day.
If the machinery were to be down for six weeks, it would result in a loss of production of more than 1,200 units and damages exceeding $30,000, based on an average cost per unit of approximately $25.
| In-house 3D printed parts | Outsourced repair parts | |
|---|---|---|
| Lead time | 1 day | 6–8 weeks |
| Loss due to machine downtime. | 1,000 dollars | 30,000 dollars |
Researchers at the AMRC Composites Center are studying ways to automate the process of moving carbon fiber plies with high precision and speed using pick-and-place robots.
However, after a period of use, the L-bracket used to hold the robot's compressed air grippers began to bend at the joints, resulting in damage and system failure.
By using 3D printing technology, researchers can quickly develop novel solutions: custom springy components with complex shapes that cannot be easily produced with traditional manufacturing tools.
Matthew Williams, a composite technician working on this project, said:
“I’ve already improved and tested five versions of a set of six grippers , which would have taken 10–15 weeks to produce using traditional machinery , and that doesn’t even include the time for real-world testing.”
The engineering services company STS Technical Group has utilized SLA (Stereolithography) 3D printing technology to develop robot grippers, replacing standard grippers with 3D-printed grippers that offer superior performance.
The team has developed custom grippers for moving and positioning fuel injectors within a manufacturing plant environment.
Switching from milled steel grippers to 3D-printed polymer grippers can help reduce the risk of scratching or damaging softer surfaces.
Furthermore, switching from the typical V-shape to a form-fitting geometry specifically designed to match the fuel injector shape increases the contact area for gripping, resulting in more precise and reliable operation.
It also helps reduce the pressure required in the work process.
A standard gripper initially mounted to a pneumatic cylinder (above).
A pneumatic cylinder assembly featuring a 3D-printed gripper made from Rigid 4000 Resin for holding fuel injectors.
A&M Tool and Design has expanded its use of 3D printing technology to produce functional parts such as fixtures and various end-use parts.
One example is when a spider coupling for the company's large lens polishing machine shipped the wrong size just two days before a major trade show. Mechanical engineer Ryan Little quickly designed a replacement with the correct dimensions and printed it using an SLA 3D printer.
The printed coupling was successfully put into practical use to drive a two-horsepower motor on a grinding machine.
When a custom-made spider coupling for a lens polishing machine arrived in the wrong size, A&M Tool and Design used 3D printing to quickly produce a replacement part from durable resin, resolving the immediate problem before a major trade show.
Generally, it is legal , but it depends on each specific case.
Reverse engineering is generally considered legal, and manufacturers can choose to use 3D printing to produce replacement parts from in-house designs without violating trade secret law.
However, if a manufacturer intends to print replacement parts for commercial purposes, it may be liable under applicable laws and may be obligated to provide designs or products that comply with safety and quality requirements as per the terms of the contract.
The UK government has conducted extensive research on the legal requirements and liabilities associated with 3D printing of spare parts, providing valuable insight into the legality of this process.
The study considered the production of both spare parts and replacement parts, as well as legal requirements at every stage of the manufacturing process in several countries, such as:
United States of America
United Kingdom
European Union
Canada
Japan
And China.
Get started with 3D printing for manufacturing replacement parts and spare parts.
Producing replacement parts and spare parts in-house using 3D printing technology is a cost-effective, fast, and efficient way to reduce machine downtime and minimize production efficiency losses.
Formlabs offers state-of-the-art SLA and SLS 3D printers with industrial-grade materials for manufacturing replacement parts and components.
You can learn more about our 3D printers or contact our experts to discuss creating the best workflow for implementing this technology in your organization.
 |
Specifications of the Formlab Form4 SLA machine. click Check price click |
 |
Formlab Fuse 1+ 30W Specifications SLS click Check price click |
