An In-Depth Look at the Anatomy and Functioning of a 3D Printer
Table of contents
· Understanding the components and mechanisms behind fused deposition modeling
· Overview: The 3 Key Aspects of an FDM 3D Printer
· Heated Extrusion System
∘ Filament
∘ Extruder
∘ Hotend
· Motion Control System
∘ Stepper Motors
∘ Rails & Rods
∘ Print Bed
· Heated Print Bed
Understanding the components and mechanisms behind fused deposition modeling
Fused deposition modeling, better known as FDM, is one of the most common types of 3D printing technologies available today. But despite its popularity, the internal anatomy and functioning of an FDM 3D printer remains a mystery to many.
In this comprehensive guide, we’ll ‘dissect’ an FDM printer and examine its core components and mechanisms to truly understand how it can transform digital 3D models into physical objects.
Overview: The 3 Key Aspects of an FDM 3D Printer
Adjusting settings on a 3D printer’s LCD interface before initiating a print job.
An FDM 3D printer works by heating and extruding thermoplastic filament material layer by layer to construct an object based on a digital file. For this process to happen effectively, an FDM printer relies on three key aspects:
- Heated Extrusion System — To melt the filament and deposit it precisely
- Motion Control System — To direct the extruder nozzle around the build area
- Heated Print Bed — To facilitate adhesion of the first layer
Understanding how these aspects fit and work together is crucial to comprehending the anatomy of an FDM printer. So let’s look at them in more detail:
Heated Extrusion System
The extrusion system is the ‘heart’ of an FDM printer and has two main roles:
- To feed and melt the filament
- To precisely deposit the molten material
This enables the layer-by-layer build process that creates the final print. Let’s examine how this happens through the key components that make up a printer’s extrusion system:
Filament
Exploring the mechanics of an FDM 3D printer, highlighting the extruder, filament spool, stepper motors, and lead screw.
The raw material consumed by the 3D printer to create an object is called filament. This thermoplastic filament, usually ABS or PLA, comes wound on a spool and feeds into the extruder system.
Extruder
Dissecting the cold end of an FDM extruder: a crucial component for filament handling in 3D printing.
The extruder, sometimes called the ‘cold end’, is responsible for gripping the filament firmly and pushing it towards the hot end in a controlled manner. It consists of a stepper motor, drive gear, idler wheel and more.
Hotend
Identifying the key components of the hot end on an FDM printer, where the 3D printing magic happens.
The hotend, as the name suggests heats up to very high temperatures of 190°C to 240°C through an integrated heater cartridge. At this temperature, the filament becomes soft and melts into a liquid state so it can be extruded easily.
Some key hotend components are the heater block, heat break and nozzle tip through which the molten filament gets deposited onto the print bed.
Now that the filament can be melted and extruded precisely, the next requirement is a system to direct this deposition.
Motion Control System
The intricate workings of a 3D printer’s extruder, where precision meets innovation in additive manufacturing.
For the hotend nozzle to deposit material accurately following the 3D model contours, the extrusion system needs to move along the X, Y and Z axes. This motion is facilitated by:
Stepper Motors
Steeper motorscoupled with precision lead screws drive movement of hotend and/or print bed along the axes.
Rails & Rods
Rails provides smooth linear motion to various components. Smooth rods resist flexing, twisting of parts.
Print Bed
Build platform where 3D printed part takes shape. Can move along Z-axis or be stationary.
The motion control system works in precision tandem with extruder drive gears that control flow rate of extruded filament all coordinated by the printer firmware. This enables accurate tracing of the toolpath for each layer.
Heated Print Bed
Safety first: A 3D printer’s hot bed plate marked with cautionary instructions to prevent burns.
While motors and mechanical motion control the deposition of each layer, the very first layer needs to strongly adhere to the print platform to provide anchorage for rest of the part.
This is achieved with a heated bed which maintains temperatures of 50°C to 110°C. Some materials like ABS tend to warp or detach from cooler platforms so a heated bed allows proper interlayer adhesion.
There are various heating technologies used:
- Heated aluminum build plates with glass tops
- Silicone heater mats
- Embedded electrical resistances
So in summary, these are the main constituent components and functional mechanisms that enable FDM 3D printing. By working together in a coordinated fashion, they allow an FDM printer to translate 3D digital designs into physical objects with precision and accuracy.
I hope this ‘dissection’ helps provide deeper insight into the anatomy that makes desktop FDM 3D printing work! Let me know in the comments if you have any other questions.
This post is originally published at 3dprintjunction.com
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