No one appreciates having “the right tool for the job” more than CNC machine operators. However, for any tool to do its job correctly, the right CNC fixture design (also called a CNC workholding fixture) has to secure and stabilize whatever part is being worked on during CNC machining.
Fixturing is complex and can be pretty challenging. However, engineers who love demanding tasks embrace the challenge, knowing how vital fixture design is in CNC machining. In addition to expert engineering, making reliable CNC fixture design also requires some science, art, and solid teamwork.
What is Fixture Design?
The best definition that can be given to a CNC fixturing design is that it is a stability and positioning agent. In addition, it is a part-holding device focused on securing, supporting, or properly mounting a part on the CNC machine.
They are engineered devices equipped to locate, hold and support a product during a manufacturing operation. The components are available in a wide range, allowing engineers to select the right one for each workpiece.
CNC fixturing design is an essential tool that ensures conformity and interchangeability during the manufacturing process. In other words, it promotes a smooth manufacturing operation.
With CNC part fixtures, the tool moves when the part moves. In the case of jigs, the tool is always stationary.
A jig serves to guide the movement of the milling cutter. However, CNC part fixtures do not show the milling cutters. Instead, they only secure, support, and stabilize the part during the manufacturing process.
Fixturing designs are significant to any production process, especially in automated manufacturing, inspection, and assembly operations. They reduce the number of stress humans exert in a typical manufacturing process.
How does fixture design work?
The sales and engineering teams work closely with the customer from the beginning to review any issues that may arise. There are three key elements when considering the design of CNC fixturing, and it all starts with the part drawing.
The part drawing
Engineers review the drawing to identify where the reference points are and all the critical features that drive the CNC fixture design.
Ideally, when a part is fixtured, it allows all critical features to be combined in one operation, maximizing control and machining accuracy.
Not having to relocate a part for numerous operations avoids potential tolerance problems in the design.
Modern fastener design is performed using a three-dimensional (3D) computer-aided design (CAD) tool, such as SolidWorks.
The CAD model of the customer’s part is imported into the design program, and models of the CNC machine’s work center pallet and work area.
From there, the CNC fixture is designed to hold the part robustly within the center of the CNC machine.
Fixtures are essential tools that ensure standardization and interchangeability throughout the manufacturing process.
These instruments serve as the foundation for CNC parts and components, giving them their rigidity and mechanical stability during processing on CNC machinery.
To put it another way, they promote a smooth production operation as they are devices designed to hold CNC machined parts (or parts) during cutting operations on CNC machines such as milling machines, lathes, laser cutters, and router machines, primarily.
Fixtures hold parts very rigidly in place while being cut or milled by a CNC machine. They must be made of a material that will not deform during machining for dimensional accuracy, so aluminum castings are often used.
Elements of fixture design
A locator is usually a fixed component of any fixture. It helps engineers create and maintain the location of a part in the fixture by restricting the constant movement of the piece.
Therefore, a locator is flexible and becomes very useful during a product of more significant variability in geometric shapes and conditions.
A clamp is said to be the force actuating mechanism of any fixture. It helps to securely hold a part in the fixture while protecting it from all other external forces.
A bracket can be a fixed or adjustable element of a fixture design. When there is a likelihood of dislocation or deflection of the critical part during imposing clamping and processing forces, supports are inserted and installed under the part.
This helps prevent part deformation. The supports must be compatible with the locators and clamps on a workpiece.
Also known as the tool body, the fixture body is the most essential structural element of a fixture.
It helps engineers maintain the spatial connection between the fixturing elements, i.e., clamps, locators, holders, and the machine tool on which the workpiece is processed.
Types of fixture design
The classification of CNC workholding fixtures is something that most people familiar with tooling don’t understand. Yes, it’s not that simple. Because it’s not simple, it’s frustrating for beginners to understand fixturing.
That’s why there are five types of fixtures, and they are classified based on CNC operations.
CNC turning is a machining operation in which parts are removed from a workpiece while rotating on a single axis. Turning fixtures are CNC devices that are used during this process.
CNC milling is simply a cutting machining process. In this process, the computer directs the milling cutter to cut the required part of the workpiece.
Drilling is a popular manufacturing process and is most prevalent in CNC machining. It simply means drilling a hole in a workpiece.
CNC boring is a machining process in which a tool is used to enlarge holes already drilled by CNC drilling.
CNC grinding involves removing a part of the workpiece with the help of a grinder. It is another popular machining process used in CNC cutting and CNC milling.
The final stage of fixture design
Engineers then review the CNC fixture design with the build team to catch any potential manufacturing issues before they become a problem.
They study how the components will be fabricated/assembled with the common goal of building the fixture as smoothly as possible. They learn how the parts will be manufactured/produced. Details related to component machining, mechanical and hydraulic assembly, and testing are planned.
Finally, the fixture design is sent to production. Two keys help minimize production problems: a thorough design process and sharing as much information as possible with the production team.
Teaching the production team up front helps them understand the design and its purpose.
Fixture design can be rewarding
Designing a fixture can be challenging because some parts are difficult to hold and process. However, following the necessary steps benefits the production side of a company and the employees, as it is rewarding to be part of a team that grows together and shares ideas and knowledge.
Maroney Company engineers have designed and built thousands of fasteners for various parts. Our team prides itself on providing solutions to complex CNC manufacturing problems and machining customer parts precisely to drawing.
Fixture Design in Northridge, CA
Fixturing is often at the top of our list when you need a quick turnaround tool for production or prototyping needs. We can design and deliver reusable tooling manufactured to your engineering specifications.
Maroney Company is an engineering and design firm specializing in creating custom jigs and fixtures. Our engineering capabilities are backed by the latest and most up-to-date equipment and technology.
Our team at Maroney Company has over 60 years of experience in precision machining and holds AS9001AD and ISO 9001:2015 certifications and DDTC (ITAR) 2022 registration.
Our complete grinding and honing department includes jig grinding, hand, CNC ID and OD grinding, centerless grinding, and sharpening mechanisms. This means our machinists can create even complex fixtures through custom CNC machining.
At Maroney Company, our service aims to take your design idea, concept, or even a mere napkin sketch and turn it into reality. Skilled technicians check the feasibility of the proposed concept, develop a suitable design and proceed with the machining process. This helps us to create a final product with customized CNC parts.
Contact Us for Your Fixture Design and Machining Requirements
At Maroney Company, we look forward to helping our customers with their fixture design and machining requirements. Please call us at (818) 882-2722 or email us at maroneycompany.com to discuss your needs and find custom tailored solutions.