Dual-extrusion 3D printing has transformed what’s possible for makers and professionals alike, especially when it comes to printing with advanced materials like PCTG. One of the biggest game changers? The use of water-soluble support filaments. With the right selection and technique, you can achieve stunning, intricate PCTG prints that were previously unthinkable. This article will guide you step-by-step through selecting and using water-soluble supports for dual-extrusion PCTG prints—so you can create complex parts with crisp detail and clean overhangs, right from your desktop.
Understanding Dual-Extrusion and PCTG
Dual-extrusion refers to a 3D printer’s ability to print with two different filaments in a single job. For functional, engineering-grade prints, PCTG has become a favorite thanks to its impressive impact strength, clarity, and chemical resistance. But with great materials come greater challenges—PCTG often demands supports for complex geometry, and removing traditional supports can be tedious and sometimes damaging. That’s where water-soluble supports shine. By printing these supports with your secondary extruder, you unlock new design freedom and ease of post-processing.
Types of Water-Soluble Support Materials
When it comes to water-soluble support materials for dual-extrusion, PVA and BVOH are the most widely used options.
- PVA (Polyvinyl Alcohol): The most common water-soluble filament, compatible with a wide variety of build materials. It dissolves in plain water, making it convenient for most users. However, it can be sensitive to humidity and may require special storage.
- BVOH (Butenediol Vinyl Alcohol Copolymer): Offers faster dissolution and better stability in humid environments compared to PVA, but it’s often more expensive. BVOH is also known for creating very smooth interfaces with prints.
Both materials have pros and cons, but the most important factor is their compatibility with PCTG in terms of printing temperature and adhesion. Some other niche options exist, but PVA and BVOH remain the standard for most hobbyists and professionals.
How to Select the Right Water-Soluble Support
Selecting the ideal support material for PCTG prints involves a few crucial considerations:
- Adhesion: The support must adhere well to PCTG during printing but detach cleanly once dissolved. BVOH tends to have a slight edge here, but high-quality PVA can also perform beautifully.
- Printing Temperature: Ensure your support filament melts within a similar temperature range as PCTG (typically 230–250°C). Too low, and it won’t extrude reliably; too high, and it may degrade or clog your nozzle.
- Dissolution Speed: If you’re on tight deadlines, BVOH dissolves notably faster in water than PVA. However, for most desktop users, the difference is a matter of a couple hours.
- Availability and Storage: Both PVA and BVOH are hygroscopic and require dry storage—ideally in a sealed bag with desiccant. Choose fresh filament from a reputable supplier, like filalab.shop, to ensure consistency.
Preparing for Dual-Extrusion with PCTG and Water-Soluble Supports
Before you hit print, preparation is key for success with dual-extrusion:
- Slicer Setup: Assign the support material to your secondary extruder in your slicer software. Adjust settings such as interface layers (the boundary between support and model) and Z distance for easy removal.
- Bed Adhesion: Both PCTG and support filament need reliable adhesion. Use a suitable build plate surface—PEI, glass with glue stick, or a proprietary adhesive sheet.
- Nozzle and Hardware: Ensure both extruders are well-calibrated. A clean, properly-sized nozzle (0.4–0.5mm) prevents clogs and uneven flow.
- Filament Dryness: PVA and BVOH print best when dry. Consider drying your filament in a dedicated filament dryer or oven at low heat before use.
Printing Process: Step-by-Step
- Load Both Filaments: Feed PCTG into your primary extruder and water-soluble support into the secondary. Purge both to ensure clean, consistent extrusion.
- Calibrate Nozzle Heights: Use your printer’s software to align nozzle offsets—critical for dual-extrusion accuracy.
- Configure Your Slicer: Assign support roles, adjust support density and interface thickness, and enable prime towers or ooze shields to minimize cross-contamination.
- Monitor the Print: Watch the first few layers carefully. If you see stringing or poor adhesion, pause and tweak your settings.
- Troubleshooting: If supports detach or warp, try increasing bed temperature or adjusting the Z gap. If supports aren’t dissolving cleanly, check for over-extrusion or insufficient interface layers.
Post-Processing: Dissolving Water-Soluble Supports
Once your print is complete, gently remove the object from the build plate and place it in lukewarm water.
- Temperature: Water around 35–45°C will speed up the dissolution without risking the structural integrity of your PCTG part.
- Agitation: Gently stir the water or use an ultrasonic cleaner for complex models to dissolve supports faster.
- Patience: Larger or denser supports may require several hours. Replace water if it becomes saturated.
- Final Rinse: After supports dissolve, rinse your PCTG print under clean water to remove any residue.
Tips for Success and Common Mistakes to Avoid
- Keep Filaments Dry: Store water-soluble filaments in airtight containers with desiccant.
- Use Quality Filament: Cheap or old support filament may cause clogs and poor dissolution.
- Fine-Tune Interface Layers: Experiment with the thickness and density for optimal balance between support and print quality.
- Avoid Cross-Contamination: Use purge blocks or wipe towers to keep colors and materials cleanly separated.
Conclusion
Water-soluble supports unlock a new world of design freedom and hassle-free post-processing in dual-extrusion PCTG printing. By carefully selecting the right support material, dialing in your printer settings, and following best practices for storage and dissolution, you can create complex, high-quality PCTG prints with smooth surfaces and crisp details. Ready to try for yourself? Explore Filalab’s collection of PCTG and water-soluble filaments and take your prints to the next level.