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Quick, Cheap and Accesable
FDM 3D Printing - Fused Deposition Moldelling
FDM 3d printing uses heated filament, passed through a heated nozzle, aimed across a solid build plate layer by layer.
Quick, Cheap and Accesable
FDM 3D Printing - Fused Deposition Moldelling
FDM 3d printing uses heated filament, passed through a heated nozzle, aimed across a solid build plate layer by layer.
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What is FDM 3D Printing?

FDM 3d printing Begins much like 2d printing, drawing out a flat image. However,  once this image is complete, another layer is extruded onto the previous layer. Eventually, resulting in a complete 3D part. The Filament spools are passed through the heated extruder, which follows a single path, laying down each layer.

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FDM 3D Printing Filaments

Fused deposition modelling uses thermoplastics to build 3d models. These come in filament spools. Usually, 1.75mm in diameter, the spools are fed through through a heated extrusion nozzle.

Furthermore, FDM filaments have a wide range of  properties compared to other forms of 3 printing. Generally, the higher the printing temperature, the better the mechanical properties. However, with increased heat comes, increased chance of warping. This is the reason that printing temperature, mechanical properties and cost all rise relative to one another.

Common Filament Properties

ABS

High mechanical properies

Temperature resistant

Susceptable to warping

PLA

Most Common printing plastic

Print with ease

Low impact strength + elongation compared to ABS.

Nylon (PA)

Good for final use

Flexible and strong

Excellent chemical resistance.

PETG

High chemical + impact resistance

Great heat resistance

Susceptable to warping

TPU

Rubber like prints

Good elongation

Low res printing

Hard to print accuratly.

PEI

Excellent Strength to weight ratio

Fire and chemical resistant

High cost

FDM 3D Printing Perameters

Here you can see the mechanics of your average FDM 3d printer. There are many variable perameters that have an effect to the outcome of a print. These include: build speed, nozzle temperature, layer hieght (resolution), Infil (density) and heat of the build platform. These are true to all printers. In contrast, Max build volume and wether a printer has a heated bed are down to which printer one is using.

The Nozzle diameter and layer height are the perameters that determine the resolution of the print. A small nozzle and a low layer height are needed fr a smooth finish. However this increases printing times.

The build volume should be considered for any 3 printed model. Desktop printers generally have a max volume of 200x200x200mm. However, industrial machines exist that can achieve 1000x1000x1000mm parts. For the most part, it still makes sense to split large models in to seperate components. 

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FDM Warpage

Warping happens, because cooling happens at different rates, depending on the form of the object. In addition, the outside of large flat sections are the most susceptable. Due to, the cooler sections shrink and pull on the hotter sections on top of them. The best way to avoid warpage is a heated build platform, as it anchors the part to the bed.

A good CAD designer should be able to spot these issues before they can happen.

FDM supports

Supports are used to prop up sections of a part that has nothing beneath it to support it.

Supports are temporary structures that can be built upon. Similarly, supports are removed after the print is done.

Supports are only neccesarry if a section of a model overhangs by 45 degreees or more. Prints are possible at lower angles, however the closer you are to 45 degrees, the more quality is compramised. There are two types of supports: standard supports, which consist of the same filament as the rest of the part. In addition, dissolvable supports can be achieved, which are usually extruded in wax. However, they do require a dual extrusion printer.

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FDM Infill

FDM parts rarely print solid. This is because 

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