Carbon fiber filament is one of those “exotic” filaments everyone wants to try printing with sooner or later. It has the tremendous advantages of being both strong and lightweight. However, it also presents its own set of challenges to print with.
To explore how to use this material, we decided to check out a product by Proto-Pasta . They offer a Carbon Fiber HTPLA (Hight Temperature PLA) filament.
It is a combination of milled carbon fibers and high-performance PLA. If “heat treated” as a “post print” process, it can withstand temperatures up to 155 deg C (310 deg F)! More on this below.
Things you will need to print with carbon fiber
- Carbon fiber filament such as the ProtoPasta Hight temperature (HTPLA-CF) we are using here.
- A steel nozzle in place of brass for the hot end.
- A test part to print. We have included a “runner” from the Dizzy Space airplane here for you to use.
Setting up your printer for carbon fiber printing
Carbon Fiber filament is extremely abrasive and will quickly wear away a standard .4mm brass nozzle on any hot end. The filament also tends to clog when printing with anything smaller than a .5mm diameter nozzle. So, the first thing to do is change out that brass nozzle with a stainless steel one.
Our “test nozzle” is a .8mm diameter stainless steel nozzle from Uxcell and is available Amazon. The larger nozzle should be a good diameter to help with the clogging issue, but we still need to make sure our slicer is set up properly.
Since carbon fiber filament is both lightweight and strong. It can be ideal as a substitute in certain applications, such as construction of a micro foam airplane where every gram counts. We will cover this in a different article about the Dizzy Space airplane.
Here are the two main items you need to address on your printer:
Swap out the nozzle.
Swapping out the nozzle is straight forward on most printers. Usually a wrench to hold the heat block and a socket and ratchet to unscrew the brass nozzle. Usually what we do when installing the new nozzle is apply some Teflon tape to the threads before reinstalling the new one. We usually snug the nozzle down, heat up the hot end to running temperatures, then snug it a second time after everything has expanded. Once this is done, recalibration of the bed height may be necessary.
Configure your slicer.
Since we changed out the .4mm nozzle with a .8mm one, we needed to make some changes. Also, since this is carbon fiber, we will need to alter our retract and travel path settings to avoid strings and clogging as well.
Our slicer of choice is Simplify3D. If you have not heard of this slicer, we recommend you look it up. There are many free slicers out there, but Simply3D can make things a lot easier along with improve the quality of your prints. Most of the slicer selections we are showing here can be adapted to your slicer.
- Update the Extruder Parameters
We updated the diameter to the .8mm value of our nozzle. Also, Simplify3D automatically set our Extrusion width to .96mm. We also turned retraction off to avoid clogging the nozzle. This is also a good practice if you print with TPU filament as well.
2. Slow the Printer Down
The carbon fiber filament is infused with tiny fibers that will not melt which will place more stress and pressure on the nozzle. So, to avoid a clog we are reducing our print speed to 15mm/s.
- Change the Travel Path
By changing the travel path, we will avoid stringing.
Simplify3D’s own site has some exceptionally good guidelines for printing with carbon fiber. If you would like to read more about them you can view them here.
- Scale the part, (if it will be Heat Treated)
The part needs to be scaled by .6% to account for shrinkage in the x and y axis and reduced by 1% expansion in z axis. One of Proto-Pasta’s co-founders, Alex, does an excellent job of explaining the reasons for this in this article
This is how you would scale your print in Simplify3D if you needed to heat treat it.
In our case, we did not heat treat any of our parts because the foam components of the Dizzy Space would never survive excessive heat anyway, so there was no need.
With all our settings in place it is time to print!
Printing with Proto-Pasta’s carbon fiber was remarkably easy. The .8mm nozzle made quick work for creating the runner. There were no adhesion bed problems, and it printed great on blue painters’ tape with nothing else applied to the tape. You can see below the thick lines the .8mm nozzle created as the print began, first with the starter outline, then next with the actual runner itself.
The runner finished printing and the Proto-Pasta’s carbon fiber sports a mat style smooth finish.
The finished item is very tough and light weight.
If you wish to learn more about heat treating the carbon fiber, we suggest you check out Proto-Pasta’s article.
If you would like to learn more about the Dizzy Space plane, you can check out the original plan here. But be sure to stay tuned and check back for our complete build article on the Dizzy Space!