Our previous article, How To Use Support Material: Part 1, delved into the specifics of how single extrusion support works and some design considerations that you might have to take into account when modeling an object. With dual-extrusion support printing, all that goes out the window.

Left, with PVA Support dissolved. Right, PVA support still attached

With multi-material printing, you don’t need to worry about bridging, you don’t need to worry about large overhangs, and you don’t need to worry about supports getting stuck in internal features. Because support materials are designed to dissolve or breakaway, you can print them as densely as you need to or as close to the print surface as possible because, in the end, it’s going to completely disappear.

There are three major types of support material: PVA filament, HIPS material, and Ionic hybrid material. PVA 3d printing filament is generally used in combination with PLA and HIPS filament with ABS because each set has similar extrusion temperatures. Ionic support material is used for advanced, high-temp materials, specifically NylonX. These are not the only support materials that exist though, as you can also use the various support materials in the LAY-AWAY Series.

Dissolving Ultimaker PVA in tap water.

How to Print with PVA Filament (Poly Vinyl Alchohol)

PVA filament is essentially what a school glue stick is made from, and is best suited for printing alongside PLA. It’s relatively low melting temperature (200C) is a perfect match for PLA filament. It’s simple to print and doesn’t warp, however, it is hygroscopic and will readily absorb water from the atmosphere. Best practices when printing with PVA support material is too dry it in the oven before printing, or keep it in a dry storage until you’re ready to use it. Printing with PVA support material is perfect for a working environment where you can’t use chemicals or sharp tools to remove support, like in schools. PVA filament only needs tap water to dissolve, and will completely dissolve in a few hours. Warm water can help accelerate the dissolving time of the PVA supports. If you are on a time limit, you can peel and break off as much as you can before soaking it in water to cut down on the wait.

How to Print with HIPS Filament (High-Impact Polystyrene)

High-Impact PolyStyrene, or HIPS filament, is a plastic that is normally used for any kind of consumer packaging. With a glass-transition temperature of 100C, it flows easily and works exceptionally when working in tandem with ABS, which has a glass-transition temperature of 105C. HIPS can even be used as a build material instead of just as support material. However, in order to dissolve HIPS filament if you’re using is as a support material, you will need to use limonene – a household cleaning solvent. Limonene is derived from the rinds of lemons and as such smell like lemon. Despite that, limonene is an irritant, and can irritate your skin or lungs if in contact for too long. When using limonene, be sure not to use a plastic container, glass would be best, use gloves when submerging and removing your part from it, and wash your hands when you’re finished.

How to Print with Ionic Hybrid Support Material

Ionic Hybrid Support Material formulated to pair with advanced materials like NylonX and NylonG so you can print more complex and functional parts in stronger materials. Ionic is both water-soluble and breakaway support material - this reduces post-processing time so your end-use parts can be applied to projects faster. Ionic's thermal stability makes it compatible with a variety of advanced materials, including Nylon and ABS. You can now create stronger and more intricate 3D printed parts. You can learn more about printing with Ionic in our guide here

When using MatterControl, there are some additional settings that will appear by changing the "Extruder Count" under Settings > Printer > Features > Hardware:

  • Settings for your second extruder's nozzle are found under Settings > Printer > Extruder > Extruder 2. Here you can change the nozzle diameter or the extruder offset. The extruder offset is used to tell the slicer how far on the X and Y axis the second extruder is from the first. It is important to calibrate this offset if this field isn't auto-populated by MatterControl.
  • Material 2 will also appear, allowing you to change the material presets for the second extruder. You can use this to automatically change your print settings for the optima settings for each support material.
  • To change which extruder will be printing your support material, find these settings under Settings > General > Support Material > Extruders. Here you want to change the support material and support interface extruder to be the same extruder, which is usually the second extruder.
  • Wipe Tower and Wipe Shield settings can be found under Settings > General > Multiple Extruders > Extruder Change. By changing these settings you both activate these print settings, like a raft, and can alter their size.
    • Of the two options, we prefer using a wipe tower instead of a wipe shield. The difference between the two is a wipe tower is a sacrificial tower in the corner of the print bed where the print head will extrude from the previously used nozzle to clear it, then wipe it to ensure there isn’t any drag between the two colors or materials. A wipe shield is a thin shell printed around your part to catch any filament that oozes from the nozzle. It encases your print, and depending on the geometry of your model, may prove difficult to remove.

Ford published a 3D model of their V6 engine block. Here I’ve printed it on an Ultimaker 3 with Ultimaker's Silver PLA and Ultimaker’s PVA.  This was a 30 hour print with many complex internal features and overhangs. You can see that the model is flawless. Even the sharp overhangs have come out perfectly clean. 

The Ford V6 Engine Block. Left is with PVA supports dissolved, right is with the PVA supports intact,

My desk needed a little plant on it to spruce it up, so I grabbed a Bulbasaur planter off Thingiverse and printed it in MatterHackers PRO ABS Teal and MatterHackers Standard HIPS Natural. This little guy took ten hours and I wanted it printed in ABS so if I want to put it on the porch or near the window, I can do that and not worry about it warping. 

There’s support both supporting his belly and inside his back, but a little time in a limonene bath:

This Bulbasaur planter was designed by sunday on Thingiverse and still has the HIPS support surrounding it.

And he’s perfect. You can see that where the base and the top of the support touched the ABS there isn’t any scarring or blemishes that are common with single-extrusion support printing.

The Bulbasaur Planter after dissolving the HIPS support material with limonene.

Everyday dual extrusion printing gets easier and cheaper, without sacrificing print quality. So consider the Ultimaker 3, BCN3D Sigma R17, or the Raise3D N2 printers the next time you think about getting a printer capable of producing beautiful dual-material prints.