Why I’m buying a filament 3D printer instead of resin
When the time comes to begin your 3D printing journey, you’ll quickly realize that there are many options available to you. In addition to being guided by your budget and the space you can dedicate to the hobby, at some point you will have to ask yourself whether you should opt for filament or resin.
While there are excellent arguments for both, I’ve fallen down the rabbit hole and it’s clear that filament is the right choice for me. Here’s why.
What is the difference between resin and filament 3D printers?
Filament 3D printing, also known as FDM (fused deposition modeling) or material extrusion, involves melting a filament which is then deposited in layers to print an object. There are many different types of filaments, from relatively fragile and inexpensive PLA to carbon fiber reinforced materials for exceptional durability.
In contrast, resin printers (like the Elegoo Mars 4 DLP pictured above) work by using stereolithography (SLA) or direct light processing (DLP) to harden the liquid, effectively curing a print in place. Resin printers effectively “grow” a model from a bath of resin.
Resin can be messy and very toxic
By far the biggest concern for me when it comes to resin printing is the toxicity of the printing material. Although water-washable resins have helped mitigate some risks, resin still needs to be handled with care, which is simply not the case when printing with non-toxic filaments like the ubiquitous PLA.
In addition to requiring personal protective equipment like nitrile gloves and ideally a respirator, resin printing requires adequate ventilation. I’m going to place my printer on a desk, which means it will share my living space. This isn’t to say that filament printers get a free pass (since some filament types, like ABS, also require adequate ventilation for safe use), but the risks associated with PLA are minimal since it’s essentially plant starch.
In comparison, resin carries a risk of exposure to harmful chemicals like formaldehyde. Some types of resin have a more noticeable “plastic” smell, which can be unpleasant if you spend a lot of time near them. There is also concern about the harmful effects these gases can have on pets, particularly birds (which are very susceptible to poisoning). I am fully aware that my cats will decide that a warm 3D printer is a great place to sleep.
Resin waste needs to be disposed of properly, and when things go wrong, that means dealing with a wet, sticky mess. When a filament print fails, you may end up with a hardened or spaghetti-like structure, but at least it’s easy to manage. Failed resin prints must still be cured before they can be disposed of, and the alcohol used in this process must also be safely evaporated.
The filament is good enough for my use case
Some people choose to use resin despite the drawbacks, and for good reason. These printers can produce incredibly detailed, high-resolution prints with wonderfully smooth surfaces. They’re also faster to print, quieter, and incredibly impressive to look at. The best 3D printing time-lapse videos are made with resin printers.
This makes resin printers particularly suitable for creating tabletop miniatures, small detailed models, mechanical keyboard keys and jewelry. They are commonly used to quickly prototype dental implants, for example.
In comparison, filament printing doesn’t look as good. Since the filament is laid down line by line, you will get more visible lines in the final print. If you want to maximize quality, you will need to reduce the size of these lines, which means increasing the time it takes to produce a print. For me, this is not a problem.
I am looking to create practical objects, mainly in PLA, for use around the home. I want to teach myself how to design designs that can solve problems around the house. I’m also not against getting out a Dremmel and some sandpaper for prints that I really want to look their best.
I’m too lazy to manage the resin post-printing workflow
When printing an object with a filament printer, you need to wait for the print bed to reach room temperature and the model to harden before diving in with your dirty hands. This usually takes around 30 minutes, if you don’t want to risk damaging or distorting the model. Congratulations, you’re done.
With resin, you’re just getting started. Remember when we talked about the toxic properties of photopolymer resins? You will need to wash off the extra resin once your print is complete. This usually involves removing any excess print material by hand, cleaning with 91% isopropyl alcohol, then washing the print one final time with soapy water.
Finally, you need to cure the resin. You can do this either by leaving your models in the sun for about 8 hours (or less, until the print is no longer sticky to the touch), or by using a curing station using UV lamps, which is usually much faster. Alternatively, you can purchase an all-in-one washing and curing station.
While I love the unparalleled detail and softness of resin prints, it takes more effort than I’m willing to put in.
The filament is cheaper and more durable
Price comparisons may not necessarily be the most useful metric due to the fact that resin printers are typically used to make smaller items and have lower print volumes, but it remains a valid point of difference between the two technologies.
Take as an example a manufacturer like Elegoo, which produces both filament and resin printers. 1kg of the most basic standard PLA costs $14 and is available in a range of colors (including mix and match packs). For comparison, Elegoo’s standard 8K resin costs $25 and comes in four colors. Water-washable resins are a little more expensive ($29), while heavy-duty resins start at $33 per kg.
For comparison, stronger filaments like Elegoo’s PETG-CF (carbon fiber reinforced) cost $19 per kg or $22 for the PLA version. These stronger filaments will always be more durable than the strongest resin. Resin prints just aren’t as durable as they are much more fragile and are less suitable for outdoor use.
For many who choose resin printers, this is not a problem. As someone looking to create functional prints from a variety of materials and wanting the flexibility to be able to produce items that can withstand the harsh Australian sun, filament is the way to go.
There is no such thing as a perfect 3D printer. Even in the world of filament printing, you must balance your desire for print volume with space and budget constraints. Some printers are faster, others offer better resolution, some use open source models, while still others rely on a closed ecosystem.
The best you can do is choose the right tool for the job, based on your wants and needs. Or, if you have the money and space to spare, buy both!
