Printing PVDF on a Bambu A1

High-performance filaments often require an industrial printer before useful work can begin.  These materials often require elevated extrusion temperatures and a heated print chamber. Our recent work with Fluorinar-C™ PVDF shows a more practical path. We printed a detailed 1/2-inch NPT pipe thread to 1/4-inch hose barb adapter on a Bambu Lab A1. This is a consumer-grade FDM printer. The finished part had clean tapered threads and a well-defined hose barb. It was printed without external supports.

The adapter was a much more useful test than a calibration cube. A cube may show that a filament can pass through the nozzle. It does not say much about the quality of a tapered pipe thread or a narrow hose connection. This model required the printer to hold the shape of the thread from the first layer upward. It also had to form the internal passage and the small changes in diameter along the hose barb. Those features made problems with extrusion easy to see.

One of the most important findings had little to do with nozzle temperature. The real problem was maintaining a steady supply of filament to the extruder. Without the AMS Lite the print would begin normally but become severely under-extruded within a few minutes. Inside the hotend the extruder must maintain enough pressure to force molten PVDF through the small nozzle opening. Any interruption in filament delivery reduces that pressure and causes the printer to deposit too little material. The AMS Lite motor assists the spool and reduces the load on the extruder. This keeps the PVDF moving at a consistent rate and allows the hotend to maintain a steady flow.

The Bambu Studio controls made it possible to keep the printer inside a stable operating window. Maximum volumetric speed was set to 1.5 mm³/s. The flow ratio was 1.00 and pressure advance K was set to 0.020. The part cooling fan was turned off to increase layer adhesion. Automatic Flow Dynamics Calibration was also turned off when the print was submitted. 

Printing two small parts at the same time also improves the result. The parts were placed far apart and printed with the normal print-by-layer sequence. While the nozzle printed a layer on one adapter, the surface of the other adapter had time to cool. This short pause between printing layers without using the fan is a simple way to improve small features while maintaining the hot layer conditions needed for PVDF interlayer bonding.

The finished adapters show what is possible to print with Fluorinar-C™ on an affordable desktop machine. Engineers do not need to begin with a large industrial printing system to evaluate Fluorinar-C™ or develop a new part. The Bambu A1 can produce detailed PVDF geometry. This gives engineers a practical way to make chemical-handling prototypes and custom fixtures in-house. It also provides a lower-cost route for proving a design before committing to machining, injection molding or outsourced production.

A successful print is not the same as a qualified fitting. The adapter shown below was produced as a printing demonstration and has not been pressure rated. Thread fit and sealing must be verified for the intended use. Chemical compatibility and process temperature must also be confirmed for each application. Even with those limits the print is an important result. It shows that Fluorinar-C™ filament made with Kynar® PVDF can produce a functional part on a consumer-grade FDM platform.

For more information about the Fluorinar-C™ high-performance filament, visit www.nilepolymers.com.

You can download the threaded barb adapter print file on MakerWorld.

Download the Fluorinar-C™ Print Profile — Bambu A1 (PDF, v1.0) for the setup and Bambu Studio settings used in this demonstration.