Should you buy a filament dryer for your 3D printer?

If you’ve ever run into recurring problems with your 3D printer, or more specifically, your material spools – then chances are that your filament might be too damp for your printing projects. This can cause errors such as stringing, poor-quality surfaces, fragile models, rough edges, and even bubbles in your prints. But what can you do about it?

Even if you own one of the best 3D printers, I’m willing to bet that at one point or another, you’ll have experienced wet filament issues. To fix or prevent this, it's a good idea to invest in a standalone filament dryer, and they're not as expensive as you might think (with some options under $50 / £50).

I didn’t realise just how much moisture plastics like PLA can absorb in humid environments when I first started 3D printing, especially during the summer season. I know 3D printers are a very costly thing to own and operate, and you might be wondering whether or not you need to invest more money into a filament dryer. I'm here to help you figure that out.

What causes damp filament?

Wet filament is caused by moisture getting absorbed by plastic materials, such as PLA, which is commonly used for 3D printing. The damp material can get converted to steam during the heating process, causing complications that will usually result in defects like stringing, bubbles, rough edges, inconsistent extrusion, fragility, and poor layer adhesion in your prints (to name just a few).

When spools of material are left out in the open, as opposed to air-tight containers, especially in more humid environments, they become susceptible to dampening. Many 3D printing groups and communities online will have you believe that wet filament is nothing more than a myth, quick to dismiss any issues occurring from it, and even suggesting that these problems can be solved with simple software and printer tweaks.

Thankfully, methods of filament drying are becoming much more common and accessible for those into 3D printing, and some newer 3D printer models (such as the Bambu Lab H2D) are shipping with advanced AMS (automated material system) units that have built-in filament drying functionality. There's also Anycubic's Kobra S1 Combo printer, which was one of the first to include an ACE Pro unit with simultaneous printing and drying functionality.

What is a filament dryer?

Filament dryers are standalone devices (not part of an AMS unit) that have been around for several years now, and range in price from premium to super affordable. These machines usually take the form of a chamber or a boxed container to house your material spools and remove any moisture from your material spools by heating them up.

Sure, you might be one of the lucky ones to have never experienced moisture-related issues in your 3D printing journey thus far, or perhaps you have a more suitable space for correctly storing your filament rolls when not in use, and that’s great!

However, for others, the only solution to wet filament is a filament dryer, an advanced AMS unit, an AMS upgrade (such as the new Sunlu AMS Heater for Bambu Lab models) or more controversially, some people use an oven to dry filament - but I wouldn't recommend this.

Which one should I buy?

When looking to buy a filament dryer to accompany your 3D printer, you'll most likely come across a ton of options from a company called SUNLU. This manufacturer is one of the most trusted on the market and specialises in 3D printing accessories and materials, including an array of filament and resin, plus ultrasonic cleaners, and it makes some of the best 3D pens too.

SUNLU has several filament dryers in its catalogue, from the more compact and circular S2 models (costing as little as $44.99), to the rectangular S4 FilaDryer – and now the newest SUNLU FilaDryer E2 machine is available to preorder at a price of $349.99 / £282.42, and offers professional-grade results, accommodating up to two 1kg spools of material.

The E2 filament dryer from SUNLU is said to offer next-generation drying temperatures between 70°C and 110°C (the ACE Pro from Anycubic offers around 40°C in comparison) and has been designed specifically for advanced engineering hygroscopic materials such as Nylon and PC. If these filaments aren’t dried correctly, the trapped moisture can vaporise during your printing process and cause numerous issues like uneven surfaces on your prints.

Another standout feature of the SUNLU FilaDryer E2 is its annealing mode, which I believe is used to cement and stabilise your prints post-processing using heat for that added layer of strength. According to SUNLU, annealing your prints can improve dimensional accuracy and enhance any mechanical properties. This isn't something I'm too familiar with, but it sounds like a great added bonus for those seeking durable and rock-solid prints.

For some alternative brands, you should also consider filament dryers from the likes of Creality (the Space Pi filament dryer is compact and affordable) as well as options from eSUN via Amazon for under $50, and there's also the Polymaker PolyDryer too. Take a look at the deals below for some top filament dryers in your region.