FDM Printing

How Does FDM Manufacturing Work?

01 Design & Printing Preparation

An FDM part begins life as a CAD design, which specifies its dimensions and features in 3D space. To prepare it for 3D printing, it is read by “slicer” software, which converts it into a series of layers along with instructions on where the extruder head of the printer needs to move to recreate the design. FDM builds parts using thermoplastic filament, which is loaded into the printer on a reel and must be heated prior to printing

02 Printing the Part

The printer feeds the filament into a heated nozzle, where it melts into a semi-liquid state. The extruder head moves the nozzle along the X and Y axes, depositing a bead of material onto the build platform. The material cools and bonds to the layer below it. When a layer is complete, the build plate moves down slightly and the printer begins building the next layer. It may also deposit a support structure, which prevents the part from collapsing.

Gantry with x-carriage and print head of an FDM 3D printer produce helical gears. Using 3D printing to produce parts

03 Post-Processing

After the build is complete, the part is removed from the build plate. The support structure is either removed or dissolved away. Often, FDM parts undergo finishing steps to improve their surface quality, such as sanding, polishing or painting. Support structures may leave marks on the surface of the part. Be sure you plan for that when printing and finishing FDM parts.

Advantages & Limitations of FDM

Advantages

Printing Speed

FDM machines can print parts faster than many other additive technologies. That means you can get your parts faster.
A Wide Range of Materials

Materials for FDM printing include acrylonitrile butadiene styrene (ABS) polymers, polycarbonates, polycaprolactone and polyphenyl sulfones.
Exceptional Toughness

FDM parts are rugged and durable. They’re ideal for demanding applications like jigs and work-holding fixtures.
The Same Material, From Prototype to Production

Often, when engineers develop prototype part designs, they must settle for a material that only approximates the physical characteristics of the final production part. That’s because they’re unable to use the same material for both manufacturing methods. With FDM, you can print prototype parts using the same materials you’ll be using for your injection molded production parts.
Build Functional Prototypes Fast

Your FDM printing service can build functional prototype parts in a few hours or days, depending on the complexity of the design. FDM can help you accelerate your time to market.
Support for Low-Volume Production

FDM manufacturing isn’t just for building prototype parts. Thanks to its speed and print quality, you can also use it for low-volume runs of production parts.
Variable Infill Density

Like many additive technologies, printing thick part walls with FDM can be challenging. It significantly increases print time and uses a lot of material without increasing wall strength. With FDM additive manufacturing, you can fill these areas with customizable lattice structures. They use less material, reduce print time and provide excellent structural strength. Your FDM 3D printing service can help you decide if variable density infill is a good fit for your part designs.

Disadvantages

Anisotropic Characteristics

Because of the way the layers of FDM parts are joined together, they tend to be weaker in the Z direction than other additive technologies.
Not Ideal for Small Parts or Details

With a minimum nozzle size of 0.4 inches, FDM isn’t well-suited to print small parts or larger parts with tiny details.
Surface Finish

Because the material is extruded in layers, the surface finish of FDM parts may not be as smooth as some 3D printing methods. That means FDM parts may need post-processing to achieve the required surface finish. Be sure to ask your Fathom representative about finishing options for FDM.

Applications of FDM

Work Holding Tools
FDM is a fast and affordable way to build customized jigs and fixtures for manufacturing.

Rapid Prototyping
The toughness of FDM parts makes them ideal for testing your designs for fit, finish and functionality. Because these 3D-printed parts are built from thermoplastics, they’re an excellent way to finalize your designs before you build tooling.

Production Parts
Some materials used to build FDM parts are chemical resistant and can endure extreme conditions. They’re ideal for demanding applications like aerospace and industrial equipment.

Aviation and Aerospace
Manufacturers are increasingly replacing metal parts with FDM components to reduce weight. Applications include components for aircraft interiors and engine components.

Consumer Product
Parts made with FDM have excellent chemical and impact resistance. That makes them a popular choice for consumer products.

Medical
You can use FDM to build surgical instruments, dental implants, hearing aids and other medical devices. In these applications, durability is a must.

Case Studies Block

What Can FDM be Paired With?

FDM parts can be post-machined to meet specific tolerances. You can bond them to other parts, such as fiberglass panels and other additive parts. In addition, they can accommodate post-installable hardware and inserts.

Traditional Technologies That Can Benefit from FDM

Are you using CNC machining, injection molding or other traditional methods to produce your prototype parts? If so, FDM may be a faster and more flexible alternative.

FDM manufacturing is well-suited for low-volume production of thermoplastic parts. That makes it a great match for your bridge production needs.