What are tax refunds for, if not to buy a bunch of spools of exotic filaments! More fun and exciting than the typical colored range of PLA I have played with so far, “exotic” filaments have come to refer to anything that goes through your FDM printer that isn’t pure ABS or PLA. They come in two categories: PLA filled with particles of something else, like the bronzeFill I played with previously, or some other type of thermoplastic entirely. It takes some time and experimentation to find the temps that new thermoplastics print at, what surfaces they adhere to, how much cooling they like, among other factors. Furthermore, every 3D printer is a special snowflake, so I’ll post here the settings that worked for me, but they may not work exactly as listed for you.

If you’re in the Washington, DC area, I’ll have models made all of these filaments on display at the NoVa Mini Maker Faire on March 15. Come take a look!

eSUN Cleaning Filament

This cleaning filament is readily available on Amazon in a super-cheap sample pack. Since you only need enough filament to run a bit through your printer, the 12 ft sample should last a hobbyist printer a long time. I’m not sure what it’s made of or how it works, but it does help remove partial nozzle clogs, and it should also help clean the nozzle after use of a filled filament or switching thermoplastics with vastly different melting rates. If there’s a bit of ABS left in your nozzle when you switch to PLA, you’ll get a clog. If there’s PLA in your nozzle when you switch to high temp nylon, it might carbonize and you’ll get a clog. If you’ve used a filled filament for any reason, there might be bits of wood or bronze or whatever in your nozzle and you’ll get a clog. I’m sensing a theme here.

If you intend to play with filled filaments, several of which are described below, I highly suggest having this cleaning filament on hand, and running some through your extruder every time you switch filaments.

Taulman 618 Nylon

Once upon a time, people who wanted to print in nylon used weed-whacker cord from Home Depot. It’s a thermoplastic and it’s just about the right size! But weed-whacker cord has all sorts of additives like fiberglass that make it significantly better at whacking weeds, but also destroy the inside of your extruder. Instead, Taulman has formulated a nylon filament that is extruded without all the nasties, and comes in a nice even diameter.

Nylon is stronger than PLA, and also more flexible. It has very low friction, making it good for use in items like hinges. It’s extremely hydrophilic, so that even on a dead winter day when the air is so dry that your nose spontaneously fountains blood, it will absorb water from the air. That’s not normally a problem, until that water passes through the hot end and flash boils to steam, which causes the hot end to spit and the print to look foamy. To prevent this, store your nylon immediately after use in an airtight container with a healthy serving of desiccant. If your filament has already absorbed water, you can bake it in the oven at 200F for a couple hours to dry it out.

Hot End: 230C

Bed: Off

Fan: Off

Print surface: Wheat Thins box taped to bed

For nylon, any cooling is too much, so make sure you’re printing in a room with even temperatures and no drafts. If you’re going to print parts with very small layers, you’ll need an alternative to allow the print to harden enough to keep its shape without providing active cooling; I have used cooling towers with success.

Nylon doesn’t stick to glass at all. If you’re using a glass build plate, you’ll want a heated bed smeared with Elmer’s Glue and water. Since I’m not using glass, I didn’t need to use the heated bed. Nylon also didn’t like sticking to blue tape. Apparently it does like to bond to cellulose fibers, so I got a handy Wheat Thins box and taped it down to my bed, which worked like a charm. No visible warping or curling, and very smooth, very accurate layers. It does tear the cardboard when it comes off, so it’s a disposable print surface – fortunately, it’s cheap, and a single cereal box can provide you with surface for a dozen prints. Also, taping cardboard to the bed adds height to the bed; be sure to adjust your Z-stop or your M212 to match the width cardboard you use.

Nylon is also handy to have on hand so that you can do cold nylon pulls to clean your extruder and nozzle, in case you don’t have the eSUN cleaning filament on hand, or if it’s just not doing the trick.

NinjaFlex

NinjaFlex is polyurethane filament for making flexible prints. It’s pretty finicky to work with, and doesn’t play well with Bowden extruders. Normal filament is pulled into the extruder by the drive gear or the hobbed bolt, and the filament itself is used as a piston to shove melty filament out of the nozzle. If you filament flexes like crazy, it doesn’t make a good piston and instead just wraps itself around your drive gear. To get around that, I printed and installed an attachment to my extruder assembly that gives the filament absolutely nowhere to go except into the hot end. (I tried to print the Adafruit attachment several times, but it was so incredibly fragile and broke each time.) I finally got the upper to work but I never managed to get a lower section that would allow filament to pass through it or fit into place. I managed to get printing even without a lower by slowing down the print speed to 15mm/sec. It’s glacially slow, but it works and the filament stopped wrapping itself up around the drive gear.

Hot End: 220C

Bed: Off

Fan: On + a desk fan

Print Surface: Blue Tape

Print Speed: Sloooooooowwww (15mm/sec for everything)

NinjaFlex is at its most flexible when printed with one perimeter. You can control how flexy each part of the print is by how thick it is and how many perimeters are used. My spool is of the clear Ninjaflex, and a one or two layer thickness is optically clear.

NinjaFlex also likes to be cooled a lot. All of the cooling! I use a small desk fan designed for cooling humans pointed at the bed to keep things extra cool.

woodFill

ColorFabb’s woodFill is a PLA filled with fine wood fibers. It creates prints that look almost as if they were made of wood, which makes a certain amount of sense because they are, in fact, partially made of wood.

woodFill smells faintly of woodsmoke when printing. It’s rather nice, actually.

Hot End: 205C

Bed: 60C

Fan: On

Print Surface: Blue Tape

I found this filament to be very well behaved, with hardly any warping or curling at all, and it bridges like a champ. It also leaves layer lines almost invisible. The pictured piece was pointed at .3mm, where each layer is clearly visible to the naked eye, yet they look like nothing more than a fine wood grain with this filament. I didn’t have any adhesion problems, but ColorFabb suggests painting your bed with a wood glue and water mixture if you have trouble.

woodFill is pretty oozy, but it’s super easy to sand off any unsightly blobs after the fact. It can also be stained with regular wood stain if you’d like to achieve a specific effect.

Carbon Fiber PLA

Proto-Pasta’s Carbon Fiber PLA is a PLA filament filled with chopped carbon fiber. It’s very rigid compared to normal PLA, which is itself already quite rigid compared to other thermoplastics like ABS. It is strong, but will break before it bends. It also exhibits far less warping and curling than normal PLA, which is impressive.

The filament I got came in a loose coil, which is generally asking for tangles. However, it’s stiff enough that that hasn’t been a problem. Instead, the filament has actually snapped a couple of times when bent by the extruder trying to feed more filament. This hasn’t yet caused me to lose a print yet, but I only just barely rescued one print in time. Printing out a spool to handle a loose coil is a must before leaving a carbon fiber print unattended.

Hot End: 210C

Bed: Off

Fan: On

Print Surface: Blue Tape

Aesthetically, this one has been a favorite among my friends. It has a lovely matte black finish and just looks awesome. However, it’s pretty expensive at 3-4x the cost of other filament, so you really only want to use it in situations where its special properties are needed. Additionally, carbon fiber is pretty abrasive, so extended use will wear out your extruder. If you’re planning on running a couple of kilos of this through your printer, invest in a handful of stainless steel nozzles.

Taulman t-glase

Taulman t-glase is another thermoplastic. It’s optically very clear and produces stunning prints. It’s available in true clear, although the spool I got is blue. It prints at PLA temps, but is stronger and more rigid. There’s also some really cool info on their website about how to get the most optical clarity out of your prints.

I had a hard time dialing in the settings for this filament, and I’m still not quite happy with it. I had to slow things down a lot to get any sort of bridging to work at all, although once I did slow it down the bridges came out perfect. It’s apparently all or nothing with the bridges for this stuff.

It also exhibits some curling even with a heated bed. It’s really not happy with slight overhangs and tends to leave gaps. However, to get the best of the visual characteristics of this material, you want to use a single perimeter, which means the resulting parts are very weak. Overall, this is a difficult material to work with.

Hot End: 215CBed: 60CFan: 50%Print Surface: Blue TapePrint Speed: 30mm/sec

Again, these settings worked, but not as well as I would like. Further experimentation is required.

Taulman suggests using the largest possible layer height to maximize the see-through nature of the filament. This also means that getting some larger nozzles (to enable larger layer heights) may be in my future.

In Conclusion…

Playing with new materials is fun! However, it can be very frustrating when nothing seems to work and Google does not, in fact, have all the answers. If you’re used to PLA, a filled PLA filament isn’t a big jump. It’s the whole new materials, like nylon and t-glase, that just don’t behave like you expect them to. These speciality filaments also tend to be more expensive than regular PLA – sometimes as much as 4x the cost. So, make sure that you save your speciality filaments for parts that need their special qualities, and not just because you like the color.