I have many good experiences with rapid prototyping and 3D printing as methods for modeling and creating proof of concept. My recent research has been surprising. For a long time, I believed that this technology could only use plastics. I had heard about metal applications but didn’t explore them until now. To my amazement, glass and ceramics are also used for rapid prototyping. This was surprising. Ceramics and glass usually melt at very high temperatures, over 2500° C.
3D Printing Exposure & Experience
My first time with 3D printing produced parts that resembled the intended object. Yet, the surface quality was lacking. I had to imagine how these parts would fit together. They broke easily and mostly acted as display models, not functional ones.
When I began using 3D printing for my parts, the technology had advanced a lot. My first batch of parts was functional, but the surface finish was rough and layered. Researchers called this method fusion deposition modeling (FDM). A few months later, I tried a different technology called PolyJet. This method greatly improved how the parts looked and how strong they were. FDM can create weak parts in thin sections, which may break along the layer lines.
3D Rubber Prototype Example
I worked with a soft, rubbery material like the stuff in running shoe soles for another project. I have come to love and appreciate rapid prototyping or 3D printing. It’s great for proof of concept modeling, prototyping, and even pre-production prototypes. My recent investigations into this technology have been nothing short of surprising. For years, I believed plastics were the only materials fit for this method. I had heard bits and pieces about rapid prototyping using metal, but did not look into it until recently. I was surprised to see that rapid prototyping uses glass and ceramics, even though it commonly uses metals. This last one was a great surprise, as ceramics and glass have very high melting temperatures, sometimes in excess of 2500° C.
3D Printing Exposure & Experience
My first experience with rapid prototyping, or 3D printing, showed me parts that looked like the object I wanted. Yet, the surface finish was quite rough. I had to use my imagination to picture an assembly from these parts. They did not fit together, broke easily, and served mainly as display models rather than functional ones.
When I began getting my parts made with 3D printing, the technology had advanced a lot. My first batch of parts worked well, but the surface finish was rough. It had a layered look that wasn’t ideal. I recall that we knew this method as fusion deposition modeling, or FDM. A few months down the road, I used a different technology, something known as Poly Jet. This technology enhances the part’s appearance and boosts its strength. Fusion deposition modeling (FDM) creates weak parts in thin sections. These parts may break along the long axis of the layers.
3D Rubber Prototype Example
I worked on another project with a soft, rubbery material. It was like what you find in the sole of a running shoe. I was surprised to find that this material can serve as an effective option for rapid prototyping. The project might need short-run molding. It’s no surprise that the same CAD files for the 3D printed parts can also be used to create the molds. This is one heck of a cost-saving measure.
Metal Prototyping
Rapid prototyping in metal part technology includes several methods. One of the most interesting is direct metal laser sintering, or DMLS for short. You can use any metal that you can powder to make parts using this technology. Suppliers say the material is “full density.” This means there are no voids in the parts made with this method. In contrast, FDM-type methods in plastics can leave voids. So, the structural strength should be good enough for functional prototypes. We still need to see if we can achieve successful heat treatment of these parts. My initial feeling on this is that I cannot see a reason why they should not be capable of this.
These great new tools can save time and money. They speed up the construction of prototype parts. This makes design changes easy and cheap, with few limits on materials. It’s surprising how well this material adapts to rapid prototyping. The project needed short-run molds. The CAD files for the 3D printed parts worked well for making molds too. This approach saves a lot of money.
Metal Prototyping
I found direct metal laser sintering (DMLS) particularly interesting for metal prototyping. This technology can use almost any metal that someone can powder. Suppliers say these parts have “full density.” This means there are no voids, unlike FDM plastic parts. This should provide enough structural strength for functional prototypes. That these parts can undergo successful heat treatment.
These tools save time and money. They make it easy and affordable to change designs. Plus, they have few limits on material use. A similar principle applies to materials like Zirconium in
Norman T. Neher, P.E.
Analytical Engineering Services, Inc.
Elko New Market, MN
www.aesmn.org