What’s in a Filament?
- Part 1: Basics to consider when choosing a 3D printer.
- Part 2: FDM versus resin printers.
- Part 3: The end to end printing process.
- Part 4: Support, and how to avoid it..
One of the most frequent questions I hear from newer 3D printing enthusiasts is, “How much filament do I need?” Before we talk about that, though, let’s make sure you buy the right filament to begin with…
Common Filament Types
Technically this header should say “common plastic types.” Filament is simply a spool of plastic in “thread” form. The most common purchase size is 1kg, but you can certainly find it in other quantities, including .5kg portions and smaller sampler packs. But I’m getting ahead of things here…
The most commonly used plastic for consumer-grade FDM printers is PLA. Period. If you’re buying your first printer or one for your kids, it probably comes with a spool of PLA, and if you need to buy one yourself, you can’t go wrong with PLA.
Most FDM printers will also accept ABS, and a few years back the 3D printing community was a bit more split between ABS and PLA. Unless you’ve got a project-specific reason for choosing ABS, I recommend sticking with PLA for all of your basic printing.
There are plenty of specialty filaments within the PLA family, but we’ll get to those in a bit.
What Brand Should I Buy?
Every year there are more and more filament makers out there. Most of them can be found on Amazon, though some of my favorites, like Filablend, only seem to be available on their own websites. For general purposes, though, my favorite brands are Hatchbox and Overture, both of which are on Amazon. I’ve also had good experiences with MeltInk3d and eSun.
Read the reviews on Amazon. Two of the most important characteristics of filament are the consistency of the diameter, and the quality of the wrap around the spool.
Your 1.75mm filament is going to feed through a hole that’s slightly larger than 1.75mm diameter; inconsistent filament will jam. If a manufacturer doesn’t wrap the filament on the spool well, it’ll tangle as it comes off the spool and can break mid-print.
If reviews seem to indicate that either of this is consistently a problem, avoid that manufacturer. I’ve purchased dozens of spools from the manufacturers I mentioned above, and very rarely had a problem with their quality.
The vast majority of consumer FDM printers take 1.75mm filament. 3mm used to be a bit more common; not so much nowadays. I recommend buying a printer that takes 1.75; just check that in the specs before you purchase.
Specialty PLA Filaments
Check out the image below this paragraph — every filament in the picture is PLA. However, there are some very fun variations in my collection, and certainly far more that I don’t have personally.
That spool on the far left is a rainbow filament. It starts out as one color, turns into another, then another…if you’re printing larger pieces, as your print gets taller the colors will change.
See the green in the middle? It’s a “glass” filament. Still plastic, but has a lovely sparkle and reflection property in the finished part.
The far right is one of my favorites. This is one of Filablend’s tri-blend filaments. If you look at a cross-section of the filament (looking straight at the end) it appears to be a “Y.” This one, the moon blend, is blue, white-ish, and grey. All three colors appear in every layer, which means that as you rotate the finished print, the colors shift.
There are plenty of other specialty PLAs as well. Transparent and translucent have some interesting applications. Woodfill can be quite nice. The plastic actually has wood in it, and the finished print will have a bit of a wood texture/grain that can be sanded and stained. Likewise, filaments like bronzefill and copperfill have enough actual metal in them that they look distinctly different from 100% plastic.
Storing Your Filament
I’m going to stress two things here: humidity and tangling.
First, 3D printer filament loves to suck up all the moisture in the air. If you leave it out, it eventually swells, which causes problems passing through the extruder, and becomes brittle. The answer: don’t leave it out in the air when you’re not printing.
I keep my filaments in large, flat plastic containers under the printer stand. Each container also has one of those laundry room moisture absorbers that you can buy for about $5. (The kind with dry pellets that eventually break down as they absorb the moisture.) Those not only keep your filament dry, they’ll amaze you when you discover that even in the plastic bin there’s enough humidity to saturate the moisture absorber in a few months, and possibly faster.
Second, tangling. When you first open your filament the loose end is most likely tucked into a hole in the side of the reel. My recommendation is that every time you take the filament off the printer to store, you should tuck the end back in one of those holes. I also tape mine, just to be sure.
If you don’t do this and you lay the spool on its side, the filament loosens up and slides. That can lead to it tangling when the printer is pulling the filament from the reel to feed the extruder. Once it’s tangled, you either have to babysit it and untangle as it feeds, or you risk the possibility of it breaking mid-print.
I’ll write another blog later describing how to deal with tangled filament…
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Until next time…