🧵 The Limitations of Filament 3D Printing: What It Doesn’t Do Well

When people talk about 3D printing, they tend to brush over the negatives and the limitations. In this blog post The Limitations of Filament 3D Printing, we will discuss this. Filament-based 3D printing, also known as Fused Deposition Modelling (FDM), has revolutionized prototyping and hobbyist manufacturing. It’s affordable, accessible, and versatile—but it’s not without its quirks. While FDM printers like the Anycubic Kobra 3 (which we use) can churn out impressive models and functional parts, there are several areas where filament printing falls short.

🔍 Fine Detail and Small Text

One of the most noticeable limitations is resolution. FDM printers extrude melted filament through a nozzle, typically ranging from 0.2mm to 0.4mm in diameter. This makes printing fine details—especially text—challenging. Fonts below 6pt often blur or fuse together, especially if the layer height isn’t dialled in perfectly. Even with optimised settings, small embossed or debossed text can lose legibility due to filament flow inconsistencies or nozzle backlash.

🧱 Surface Finish and Layer Lines

FDM prints inherently show layer lines, which can be aesthetically unappealing for consumer-facing products. While post-processing techniques like sanding, priming, or vapor smoothing (for ABS) can help, they add time and labour. Compared to resin printing, which offers near-smooth surfaces out of the vat, FDM prints often require extra effort to look polished.

🧊 Overhangs and Bridging

Gravity is not your friend when printing overhangs. FDM struggles with unsupported geometry beyond 45 degrees, often requiring support structures that leave marks or require cleanup. Bridging—printing filament across gaps—can work in small spans, but longer bridges tend to sag or string unless carefully tuned.

🎨 Limited Material Properties

While filament options like PLA, PETG, ABS, and TPU offer a decent range, they don’t match the mechanical or aesthetic properties of industrial-grade materials. High-temperature, flexible, or transparent parts often require specialised filaments and upgraded hardware. Even then, results can be inconsistent compared to SLA or SLS technologies.

🧩 Dimensional Accuracy

FDM prints can warp, shrink, or expand depending on the filament and environmental conditions. This makes tight tolerances tricky, especially for snap-fit parts or mechanical assemblies. Calibration helps, but it’s rarely perfect out of the box.

Filament 3D printing is a fantastic tool—but knowing its limitations helps you design smarter and avoid frustration. Whether you’re printing puzzle coasters, retro gaming accessories, or NFC-enabled gadgets, understanding where FDM shines (and where it stumbles) is key to getting the most out of your machine.

If you have any questions, don’t hesitate to contact us here.