Fused Deposition Modeling (FDM) and Its Main Limitations

>>Fused Deposition Modeling (FDM) and Its Main Limitations

Fused Deposition Modeling (FDM) and Its Main Limitations

Over the last quarter of a century 3D printing has developed from an experimental technology into a mainstream manufacturing technique. Some of you might already have a desktop 3D printer in your office or at home. Many others will have seen a 3D printer operating, or have read about the development of this industry.

An increasing number of businesspeople, artists and scientists are recognizing the high-quality and cost advantages of 3D printing. 3D printed models are frequently used to demonstrate new product ideas and architectural designs. The fact that these 3D models are based on computer graphic files gives them an incredibly high level of accuracy. Making accurate models with more traditional manufacturing methods takes longer and is also more costly for small batches.

At one end of the scale you can now find industrial 3D printers costing tens of thousands of dollars, while at the lower range, 3D printer kits allow people to build their own machines for a few hundred dollars. So if you consider yourself a tinkerer with good DIY skills you can even build your own 3D printer. In the process you can save yourself a good sum and have a fun and creative experience.

As 3D printing techniques and 3D printers continue to improve, and more high-quality filaments (3D printing materials) become available, the range of items you can create expands accordingly. It seems like the 3D printer is going to become as familiar to us as the office computer. This is one of the reasons why many education authorities are now introducing 3D printers and 3D printing lessons into their schools.

What is Fused Deposition Modeling?

Fused deposition modeling (FDM) is the most popular 3D printing method used today. You might not know the technical name, but if you see a 3D printer at work there is a good chance that it operates with this technology.

After you send your graphic object design file to be printed, the FDM 3D printer starts to extrude a melted layer of thermoplastic filament (typically ABS or PLA) onto its build tray. The printer extrudes layer after layer of filament and the 3D object takes shape before your very eyes.

Most models are created within a support structure printed onto a heated build plate with polyimide tape (such as Kapton) that is removed once the build is completed and cooled-down. This object building process is fun to watch, especially for kids and the young at heart. For this reason many 3D printer manufacturers leave the printing area open so you can see how the object is built up.

Why the Need for Other 3D Printing Methods?

Despite all the 3D printing achievements made possible through FDM, it has its limitations. Three of these key limitations are the range of materials you can replicate, difficulties 3D printing finely-detailed items, and finished product quality issues.


Best-suited for use with Plastic Materials

One of the most important issues is the restricted range of materials you can replicate through FDM. Certainly it is fun to create DIY plastic household or garden products on your 3D printer, but these plastic materials cannot meet industrial and commercial demands for more sturdy materials. The Selective Laser Sintering (SLS) method with powdered filament is usually preferred for 3D printing in metals. The 3D printing of glass and ceramics has also advanced from the experimental to the practical stages with powdered filaments the 3D printing material of choice.

It is important to point out that FDM 3D printers remain the most suitable ones for home and office use, not least because of the potentially explosive nature of powdered-filaments. These types of printing materials are definitely designed for the professional 3D printer operator and not for the tinkerer.

3D Printing Detailed Objects

If you need to 3D print an object with very fine details you might also find that your FDM 3D printer cannot meet your expectations.  Many experts believe that the stereolithography (SLA) method gives much better results when working with highly-detailed designs. SLA 3D printers use a resin-like material with the objects created by passing an ultraviolent laser beam over the filament. SLA allows your to create objects with a layer resolution as fine as 25 microns, while you could expect an FDM 3D printer in the lower price range to deliver just 100 microns resolution. This improved resolution of SLA 3D printing is the key to building objects with very fine and small features.

Finished product quality

Removing a finished object from the 3D printer tray can also adversely impact the quality of the finished product. Carefully removing the support material is one of the most delicate of 3D printing operations. There is no 100% guarantee you remove the support material without scratching or even more seriously damaging the object.

Even if you are not creating highly detailed objects you might still find that FDM cannot deliver the high-quality product you desire. Sometimes you might notice that the filament is extruded in a way that leaves lines between the printed layers. You can often get rid of these lines through sanding or using special finishing products but this is extra work.

Although there are these limitations, the FDM method is still the ideal choice for most as it’s a great combination of ease of use, safe to use in nearly all environments, low equipment cost, and low cost of consumables.

By | 2018-08-07T09:15:58+00:00 July 27th, 2016|Articles|Comments Off on Fused Deposition Modeling (FDM) and Its Main Limitations

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