We have developed a head that has an external blower fan which is directed over the nozzles for use with PLA and other low temp materials such as PCL. This improved airflow ensures that extruded material solidifies instantly, giving improved bridging and overhang performance and allowing for faster printing without losing shape. The head retains its original fan for the purpose of keeping the cold side of the heat break cool and this kicks in when ever the heater block is >60°C. It also increases in speed when the blower fan is activated by the cooling features of Cura.
The enclosed build volume on our machines is perfect for most materials, but not so for PLA, because of its low softening point or glass transition temperature (Tg) – it can easily deform or swell and get stuck in the Bowden tubes, particularly if it has absorbed moisture. When printing with low temperature materials we recommend leaving the door open and even removing the side window to allow more air circulation – this also helps to stop the ambient fan kicking in to extract the hot air from the build volume. (New post here shows a comparison of the results against our standard single material QuickFill head)
Getting this head working in the current released version of AutoMaker (4.01) is easy – just extract the content of this zip file into the \Common\ folder of your install directory of AutoMaker and it will put all the files you need in the correct place. RBXDV-S3.ZIP There is a readme with more detail in the zip.
We’ve included the STL file that we print to attach the blower to the side of the head and direct the air over the nozzle, please feel free to have a go at designing a better one that suits your needs.
We’ve produced a few of these heads to gauge interest and they are on the shop now priced at £89.90 each.
