One of the most troublesome aspects of 3D printing is when the final product is just not smooth. In the end it’s still layer on layer manufacturing and everything above 25 microns resolution definitely needs some smoothing to get a real end product feel.
Besides layer height, a print can have undesired abrasions and bumps. Therefor, many 3D printing enthusiasts utilize some method of finishing. There are many methods ranging from Acetone vapour to machines like the Polysher. Japanese scientists at Waseda University have now added another method to the list: 3D-CMF.
3D-CMF stands for “3D-Chemical Melting Finishing”. The university has described it as a “process to dramatically improve the quality of 3D printed products”. Kensuke Takagishi and Professor Shinjiro Umezu were the pioneers of this new method. The method itself focuses solely on FFF / FDM type objects.
The method involves the use of solvent chemicals inside a pen-style device. The chemicals are applied on the structures that need to be smoothened via the pen. The chemicals then dissolve the excess, unwanted material resulting in a smooth finish. All these experiments were performed on ABS prints. Unfortunately, there is no data about how the method affects PLA.
The researchers have concluded that 3D-CMF produces no harmful residue. This makes it safer to use than certain polishing techniques that use more harmful chemicals.
Basically, 3D-CMF can save you money. Instead of buying a new high-cost printer to achieve high resolution prints, 3D-CMF presents an affordable solution in order to get smoother prints. The reason a lot of printers can be low cost is because the use of cheap hardware (rods, motors, frame et cetera). With 3D-CMF it’s not necessary to invest in expensive hardware, cause in theory you can achieve the same end result by using 3D-CMF.
Another advantage of this method is increased accuracy. Since the device is the size of a pen, users can easily manoeuvre it. It also means that it is easier to use than, for example, Acetone finishing. Most Acetone finishing requires a chamber to house its chemicals. The 3D-CMF is safer, simpler and more user-friendly. The researchers also stated:
“In addition, we verified that 3D-CMF has superior performance for the selective treatment of 3D printed structures with complex shapes compared with the acetone vapour treatment”.
The researchers are also claiming that using the method increases structural strength of the prints. They performed an analysis looking at the insides of the structures during tests. As a result, they observed that the smoothened surfaces were hardened, giving prints more structural solidarity.
The whole 3D-CMF study is available here via Nature. It also contains useful data on how the researchers measured the strength of ABS prints.