Printing temporary structures in another material

Hello,

It would be useful if temporary structures could be printed in another material: e.g. wax or a mixture of pla and wax. It would be a lot easier to remove those temporary structures after the object is printed. Has anyone tried this?

BTW: it requires some way of specifying which parts have to be printed using which material. AFAIK this is not possible with STL. Another problem is changing material: is this possible without adding a second extruder?

Any thoughts/suggestions?

Stefaan

There are dissolvable filaments that are available.

Also, I believe there is a way to specify which material is the support material, but I can remember off the top of my head.

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sclaes
It would be useful if temporary structures could be printed in another material: e.g. wax or a mixture of pla and wax. It would be a lot easier to remove those temporary structures after the object is printed. Has anyone tried this?

Yes, many people have tried this, including myself. It's still very experimental, but some people have had good success. PVA as support for PLA, PLA as support for ABS, and HIPS as support for ABS have all been successfully used.

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sclaes
BTW: it requires some way of specifying which parts have to be printed using which material. AFAIK this is not possible with STL.

Just have separate .STL files for each material, at least until a better format is supported. Or, for a support material, have the slicer automatically generate the support material locations. Some slicers are better at this than others.

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sclaes
Another problem is changing material: is this possible without adding a second extruder?

Not really. An automatic way of switching materials on each layer is needed, and it needs to be done reasonably quickly. With a single extruder and hot end, you would have to purge the remaining melted material from the hot end before printing with the new material, and you would still need some way of switching materials automatically. This would take a long time, make a mess, and waste material.

It may be possible though to create a dual material print head with one extruder motor and two hot ends, which is what these guys are trying to create here: [www.kickstarter.com]

Edited 1 time(s). Last edit at 03/07/2014 05:07PM by NewPerfection.

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As gmh39 pointed out, there are dissolvable support materials, and there is also a way to specify which extruder is used to print support. It will require a dual-extruder setup, but both Slic3r and Cura have settings that let you specify one extruder for the part and another extruder for support material. Where this all takes place in your slicing program, you can use your regular STL file and your slicing program will generate the appropriate g-code.

All professional FFM or FDM use that method either a dissolvable material or a different material that doesn't bond. Basically most software should allow you to choose a head for support if it is capable of multihead and then of course load support material in that extruder