Here at Filabot we’re always testing out and trying new processes and products to expand our knowledge and have some fun.
Printing with metals is a seriously cool thing and we’ve been hard pressed to try it out ourselves for a variety of reasons, including part development for some of our custom side projects.
So we did what any of you might do and went on thingverse to download a file for a 3D skull. Alas, poor Yorick!
The link for the original source file: https://www.thingiverse.com/thing:311111
When creating a metal print, casting is the go-to for most desktop users. Casting is a common technique for creating metal parts with complex geometry efficiently and easily. 3D printers can make this technique accurate and economic and there are high-end printers designed specifically for this process like 3D Systems ProJet MJP 2500W.
This is an attractive process for owners of any desktop 3D printer who want to create metal parts, however sintering metal is also a common commercial technique which has been coming into the desktop creation world. We went with sintering because as pretty as the ProJet is, we don’t have the extra mula to dish out for it quite yet.
The Virtual Foundry has developed their “Filamet” to create solid metal parts using a desktop 3D printer. Filamet is 3D printer filament that is mostly powdered metal. When sintering, we used the virtual foundry filamet to turn the skull design we downloaded into a solid metal part.
Sintering is the process of solidifying metal through heat, in our case cooked in an oven in our shop one rainy afternoon.
The basic process for casting and sintering a metal printed part:
- A polymer combined with a powdered metal is printed into any design.
- The polymer is removed from the part leaving the metal powder in a process called debinding. Usually mixed with a solvent to dissolve it.
- The part is sintered together at a temperature near the melting point of the metal.
With the Virtual Foundry Copper Filamet the process was slightly different:
- The Virtual Foundry Filamet uses heat to de-bind the part, vaporizing the polymer binder, instead of dissolving it with a solvent. Pretty neat.
- Virtual Foundry requires that part to be suspended in a paste called “Black Magic” to keep the part from deforming during the sintering process. “Black Magic” comes with the filamet when purchased.
The main disadvantage with any sintering process is that the part will shrink by up to 20%. However, this can be accounted for by designing a larger print.
Our Review of the Virtual Foundry Copper Filamet:
Printing with the material was fantastic. The prints were highly detailed with a .4mm nozzle and .12mm layer height and there were no clogging issues. Managing the filament while printing was difficult: due to the high metal content it is extremely brittle. After it was warmed with a heat gun and wound onto a larger spool it worked fine and didn’t break.
Caveat: the oven we used was quite small so we weren’t able to suspend the part in enough of the “Black Magic” to keep it from deforming.
The oven could barely reach the sintering temperature for copper (1800F). We would have done better with a higher temperature and larger oven for this process. We still managed to create a solid copper piece first try when following the instructions on The Virtual Foundry website.
When finished the deformations and burrs were ground off and the piece was tumble polished.
And viola! Alas, poor Yorick sits in our shop, gazing down upon us as we work. A metallic skull perfect for parties, summoning the dead, or attaching to your keychain.
Thanks for reading,
The Filabot Team