Four Heads Are Better than One with Stacker S4 3D Printer

It hasn’t occurred as quickly as the hobby printer explosion that began in 2012, but a new wave of 3D printers is slowly starting to emerge that implements industrial-grade technology at somewhat more affordable prices than are available now. Manufacturers such as Roboze and 3ntr have released machines capable of handling industrial-grade materials without having to rely on companies like Stratasys. On April 25-29 at Hannover Messe, the world's leading trade fair for industrial technology, another new 3D printer offered manufacturing-level 3D printing with quad-extrusion capabilities.

The Stacker S4 is the evolution of the original Stacker 3D printer, launched on Kickstarter in February 2015 by startup Stacker, LLC. The original Stacker brought some interesting features to the world of fused deposition modeling (FDM) 3D printing. For instance, the use of four separate extruders allows the Stacker to 3D print four copies of the same object in four different materials and colors. Single-object printing can also be performed with one extruder, and multi-material or multi-color printing on a single object can be used with the four print heads. The original Stacker also featured an expandable Z-axis, allowing for a build envelope that ranged from 250 mm x 450 mm x 220 mm to 250 mm x 450 mm x 600 mm (9.8 in x 17.7 in x 8.7 in to 9.8 in x 17.7 in x 23.6 in), but that capability seems to be missing from the latest version of the Stacker.

The mobile Stacker S4 3D printer features a large build volume. (Image courtesy of Stacker.)
The most noticeable upgrade that the Stacker S4 brings to the table is size. With the creation of the Stacker S4, the Stacker team seems to have foregone the expandable Z-axis of the original and simply given the new machine an impressive build volume of 355 mm x 525 mm x 655 mm (14 in x 20.7 in x 25.8 in). To carry this large gantry around, the S4 has a mobile cart, making it suitable for transport in  lab or school environments. Also included is a universal filament mount that supports the four material spools necessary for quad printing. Still, many of the original features of the Stacker S4 remain, such as a heated aluminum bed, layer thicknesses as fine as 100 microns, and an SD card reader.
The Stacker S4 allows simultaneous 3D printing of four copies of the same object with different materials. (Image courtesy of Stacker.)

The machine also uses Stacker’s “hybrid” hot end, which allows users to swap nozzles when using materials with higher melting temperatures, such as nylon and co-polyesters. This, along with the ability of the printer’s four extruders to reach up to 300°C, opens the S4 up to 3D printing a wide variety of materials. In particular, the machine is being marketed for use with colorFabb’s wide range of filaments. Other than the ability to 3D print four objects at the same time, the Stacker platform does not bring a huge amount of innovation to fused deposition modeling technology. If the printer could use these four print heads to fabricate four different objects or four different portions of the same object, similar to Autodesk’s Project Escher, its potential for industrial use would be much greater. However, for producing batches of objects, particularly with colorFabb filaments, the Stacker S4 could come in handy. Either way, the platform’s existence indicates that there may be a demand for industrial-grade machines. If so, there will surely be a new wave of more affordable, professional 3D printers that could one day enable a shift to local 3D printing of end parts.