Polycarbonate is a interesting material in the way that it´s extremely durable. It also has a higher Glass Transisiton temperature (147°C) than many other 3D printing filaments. PC is used in many areas for parts that need high level of durability and strength. Although there are 3D Printers that are specifically designed to print hight temp materials like PC you can do it with other printers aswell. As long as they can handle the high extrusion temperature around 300C.
The OpenRC Truggy
When i was working on the OpenRC Truggy and finally got access to Polycarbonate filament it opened up new possibilities for the project in terms of durability. As a example, i had struggled with the internal driveshafts as i wanted to keep the size a standard driveshaft you would buy in the store leaving room for design changes very small. In the end Polycarbonate was the only material that would stand the forces applied reasonbly well with Taulman 3D´s “Tritan” (Co-polyester) in second place.
Print Settings (Replicator 2X)
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- Printer is fully enclosed.
- Extruder temp is set to 280C
- Buildplate is set to 120C
- Raft is on
- Print speed at 50mm/s
Buildplate
As a buildplate i use 6mm glass with a thin layer of ABS/Acetone mix applied to it which the Polycarbonate sticks to very well.
Regarding the raft i have set the distance between the raft and the model to 0,0mm. It might sound crazy but it makes for perfect adhesion to the raft, the model sticks to it very well but is still removable without any problems (no need for tools).
Play around with speed, depending on what i´m about to print i change it back and forth, now it´s set to 50mm/s for insets and outlines and 70mm/s for infill.
Keep in mind that printers behave differently.
Also, a word of warning! I´m no plastics expert but as i understand when heated PC does create toxic fumes so be careful.
This profile is set to use 0.15mm layer height, and it also has an buildplate offset of 6.0mm as i´ve got a glassplate on top of the buildplate!
Hygroscopic
Just as many other Engineering polymers, Polycarbonate is hygroscopic and will absorb moisture which is not a good thing. To deal with this i always dry PC before printing it. I use a dehydrator and leave the spool over night which is usually enough.
Be Careful
But it´s said that with great powers come great responsibility. Polycarbonate can be challenging to print introducing a high level of shrinkage with all that comes with that. It also needs to be printed at temperatures as high as 300°C. Also as mentioned above, when heated Polycarbonate can create toxic fumes so be careful and see to it that the printer is placed in a suitable environment with adequate ventilation.
The conclusion
In the right conditions, a thought out geometry and right settings what you get is a 3D printed part that´s really, really tough. But as always with 3D printing there are alot of parameters that come in to play to get the perfect print. Once dialed in PC offers mechanical properties in terms of durability that´s hard to find in other materials suitable for desktop 3D printers right now.
Polycarbonate filament is available at CreativeTools in Sweden among other places.