What Is 3D Printing? A Complete Beginner’s Guide to FDM

3D printing is a technology that allows us to produce physical objects from digital models. From phone stands and organisers to replacement parts and machine components, these objects can be created by building them one thin layer at a time.

Unlike a normal printer that places ink on a flat sheet of paper, a 3D printer produces an object with length, width and height.

Today, 3D printing is no longer limited to large factories, engineering companies or research laboratories. Machines have become more affordable, software is easier to use and thousands of printable 3D models are available online.

But what exactly is 3D printing, and how can a digital file be turned into a physical object?

What Is 3D Printing?

3D printing is a manufacturing process that creates a physical object from a digital 3D model by adding material layer by layer.

This process is also known as additive manufacturing.

The word “additive” is used because material is gradually added until the object is complete. This is different from processes such as CNC machining, where material is cut away from a larger block.

For example, to produce a phone stand using a 3D printer, the machine first prints the bottom layer on the build plate. The second layer is then deposited on top of the first, followed by the next layer until the entire phone stand is complete.

Each layer may be only around 0.1 to 0.3 mm thick, depending on the settings used.

Do All 3D Printers Use Filament?

No.

3D printing includes several different technologies. Some of the most common are:

• FDM, or Fused Deposition Modelling
• Resin printing, including SLA, DLP and MSLA
• SLS, or Selective Laser Sintering
• Metal 3D printing

For home users, schools, small workshops and many small businesses, the most common type is FDM.

This article focuses on FDM because it is generally more affordable, widely available and suitable for a broad range of everyday projects.

What Is FDM 3D Printing?

FDM is a 3D printing process that uses a long strand of plastic known as filament.

Filament is normally supplied on a spool. During printing, it is pulled into a heated section called the hotend.

The filament is then:

1. Heated until it softens or melts.
2. Pushed through a nozzle.
3. Deposited onto the build plate along a programmed path.
4. Cooled until it becomes solid again.
5. Covered by the next layer until the object is complete.

The nozzle moves according to the shape of each layer, while the printer gradually changes position along the Z-axis.

This process may repeat hundreds or thousands of times, depending on the height of the model and the selected layer thickness.

Main Parts of an FDM 3D Printer

Although printer designs vary, most FDM machines share the same basic components.

Filament

Filament is the raw material used to create the object. It is commonly sold in 1 kg spools with a diameter of 1.75 mm.

Extruder

The extruder uses gears to grip and feed the filament towards the hotend.

Some printers use a direct-drive system, while others use a Bowden setup. The difference affects how the filament is delivered to the nozzle.

Hotend and Nozzle

The hotend heats the filament, while the nozzle controls how the material is deposited.

A 0.4 mm nozzle is the most common standard size. Smaller nozzles can produce finer details, while larger nozzles can deposit more material and reduce print time.

Build Plate

The build plate is the surface where the object is printed.

The first layer must stick properly to this surface. If it does not, the object may move, lift or fail before the print is complete.

Motion System

Motors, belts and rails move the nozzle or build plate along the X, Y and Z axes.

The accuracy of this movement affects the shape, dimensions and surface quality of the printed object.

Cooling Fans

Cooling fans help solidify the filament after it leaves the nozzle.

Correct cooling is especially important when printing overhangs, bridges and small details.

How Does a Digital Model Become a Physical Object?

A typical 3D printing workflow consists of four main stages.

1. Obtain a 3D Model

Every print begins with a digital 3D model.

The model can be obtained in several ways:

• Downloaded from websites such as Printables, MakerWorld or Thingiverse
• Designed using CAD software
• Created in a 3D modelling application
• Captured using a 3D scanner
• Generated using an AI-based 3D platform

For mechanical projects such as brackets, mounts and enclosures, CAD software such as Fusion, SolidWorks, FreeCAD and Shapr3D is commonly used.

For artistic models and characters, Blender is often more suitable.

Common file formats include:

• STL — a widely used mesh format for 3D printing
• 3MF — can store additional information such as orientation and project settings
• OBJ — often used for visual models and textures
• STEP or STP — a CAD format that is generally easier to edit than STL

However, most printers cannot use a 3D model directly. The file must first be processed using slicing software.

2. Prepare the Model in a Slicer

A slicer is software that converts the 3D model into instructions the printer can understand.

Popular slicers include:

• Bambu Studio
• OrcaSlicer
• PrusaSlicer
• Cura

Inside the slicer, the model is digitally divided into hundreds or thousands of thin layers.

The user can also adjust settings such as:

• Layer height
• Nozzle temperature
• Build plate temperature
• Print speed
• Wall count
• Infill
• Supports
• Cooling
• Filament type

After the settings are selected, the slicer generates a set of machine instructions, commonly known as G-code.

G-code tells the printer where the nozzle should move, how much material should be extruded and what temperatures should be used.

3. The Printer Builds the Object Layer by Layer

When printing begins, the printer heats the nozzle and build plate according to the selected material profile.

It then starts producing the first layer.

The first layer is particularly important because the rest of the object is built on top of it. If the first layer does not stick correctly, the print may fail even when the model and other settings are correct.

Once the first layer is complete, the printer continues adding material until the entire object is finished.

Print duration depends on several factors:

• Object size
• Layer height
• Print speed
• Nozzle size
• Infill amount
• Number of walls
• Use of supports
• Number of objects on the build plate

A small object may be completed in less than one hour. A large or highly detailed model may take more than a day.

4. Remove and Finish the Object

After printing is complete, the object must be removed from the build plate.

Some parts can be used immediately, while others require additional work such as:

• Removing supports
• Trimming excess filament
• Sanding the surface
• Joining multiple printed parts
• Painting
• Installing screws, magnets or electronic components

These additional steps are commonly referred to as post-processing.

What Materials Can an FDM Printer Use?

FDM printers can use many different types of filament. Each material has its own advantages, limitations and printing requirements.

Material	Main Characteristic	Common Uses
PLA	Easy to print, rigid and dimensionally stable	Models, organisers, decorations and prototypes
PETG	Tough and generally less brittle than PLA	Everyday functional parts
ABS	Heat-resistant but more prone to warping	Enclosures and technical parts
ASA	Heat- and weather-resistant	Outdoor and automotive parts
TPU	Soft and flexible	Covers, grips, gaskets and protective parts
Nylon	Tough and wear-resistant	Gears, hinges and selected mechanical parts

For beginners, PLA is usually the easiest material to start with because it prints at lower temperatures and is less likely to warp.

However, there is no single best material for every project. Filament should be selected based on function, operating temperature, load, flexibility and environmental conditions.

What Can You Make With a 3D Printer?

One of the main advantages of 3D printing is the ability to produce objects that are customised for a specific user or application.

Common examples include:

Everyday Items

• Phone stands
• Cable organisers
• Storage containers
• Hooks
• Tool holders
• Replacement clips

Projects and Hobbies

• Figurines
• Props and cosplay parts
• Robots
• RC components
• Dioramas
• Decorative lamps

Mechanical Design

• Brackets
• Mounts
• Enclosures
• Jigs and fixtures
• Prototypes
• Assembly tools

Business Applications

• Custom products
• Personalised gifts
• Product prototypes
• Small-batch manufacturing
• 3D printing services

3D printing is particularly useful when only a small number of parts are needed or when each part must be customised.

Advantages of 3D Printing

Easy Customisation

Each object can have a different size, shape or name without requiring a new mould.

Suitable for Prototyping

A design can be printed, tested and improved quickly. This makes it easier to identify problems before the final product is manufactured.

No Dedicated Mould Required

Injection moulding normally requires specialised tooling, which can be expensive. FDM printing only requires a digital model and filament.

Ability to Produce Complex Shapes

Certain internal features and complex geometries are difficult to manufacture using conventional methods but can be easier to produce with 3D printing.

Suitable for Low-Volume Production

For one-off parts or small production runs, 3D printing may be more practical than preparing dedicated manufacturing tooling.

Limitations of 3D Printing

Although 3D printing is useful, it is not the best solution for every application.

Printing Can Take a Long Time

Even a relatively small object may require several hours to complete.

Visible Layer Lines

Because the object is built layer by layer, fine lines are usually visible on the surface.

Strength Is Not Equal in Every Direction

Printed parts are generally weaker between layers than along the printed lines.

Print orientation should therefore be selected based on the direction of the expected load.

Dimensional Accuracy Has Limits

Holes, slots and mating parts may require additional clearance or tolerance so that the components fit together correctly.

It Is Not Always Cheaper

For products already manufactured in high volumes, buying the finished product is usually cheaper than printing it yourself.

Some Materials Are More Difficult to Print

Materials such as ABS, ASA, nylon and certain engineering filaments may require an enclosure, filament dryer, higher temperatures or suitable ventilation.

Is 3D Printing Easy for Beginners?

3D printing is much easier today than it was several years ago.

Many modern printers include features such as:

• Automatic bed levelling
• Automatic Z-offset calibration
• Filament runout sensors
• Wi-Fi monitoring
• Built-in cameras
• Automatic flow calibration
• Material presets

However, a printer still cannot solve every problem automatically.

Beginners should understand a few basic principles, including:

• Keeping the build plate clean
• Choosing the correct filament
• Using a slicer
• Selecting the correct model orientation
• Knowing when supports are needed
• Identifying common print problems

A well-designed printer can reduce setup and calibration work, but user knowledge is still important for producing consistent results.

What Do You Need to Get Started?

To produce your first print, you will usually need:

• An FDM 3D printer
• Filament, preferably PLA for the first few prints
• A computer or compatible mobile device
• Slicing software
• A printable 3D model
• Side cutters for trimming filament or removing supports

Some printers include sample filament and test models, allowing users to begin printing immediately after setup.

Before buying a printer, it is also important to consider build volume, project type, local support, filament cost and maintenance requirements.

Final Thoughts

3D printing is a process that produces physical objects from digital models by adding material layer by layer.

In FDM printing, filament is heated and pushed through a nozzle before being deposited onto the build plate.

This technology is useful for prototypes, replacement parts, customised products, hobby models and low-volume mechanical components.

Although modern printers are becoming easier to use, good results still depend on material selection, model orientation, slicer settings and a basic understanding of the printing process.

Once you understand how 3D printing works, the next step is learning how to choose your first printer, prepare a model in a slicer and complete your first successful print.