It is 2.30 metres high, 50 centimetres wide, weighs almost 20 kilograms and is the largest spoon that WMF has ever produced. Both its purpose and its manufacture, in which 3D printing plays a central role, are anything but normal. Read on to find out more about this giant spoon.
Of course the giant specimen is not meant for conventional use but rather has been designed to highlight an optical phenomenon that anyone who has experienced the reflections and optical distortions of looking into a polished bowl of a spoon (the concave front of a spoon) would be familiar with. People interested in an explanation for this special optical feature will want to check out the "Viseum", the museum for optics and precision mechanics in Wetzlar. This is where the EUR 10,000 WMF exhibit can be found, and it demonstrates the origin behind these reflections in XL format, so to speak.
Just as impressive as the spoon itself is the process of how it was made, most of which took place at the WMF model building studio in Geislingen. "While the manufacture of single oversize cutlery pieces is not unusual, we have never made anything of this size to date. However, not least due to 3D print technology, this project was completed quickly and without any problems", says Gerd Greiner, manager of the model building studio.
Real-life cutlery as template for the giant spoon
The well-known "Palma" WMF cutlery served as a template for the giant spoon. As part of a first step, the CAD data of the original Palma spoon was adjusted to the required size on the computer. This data was then transferred to the voxeljet service centre, where a high-performance printer VX1000 using the 3D printing method produced a plastic model of the bowl of the spoon.
The industrial-type 3D printers from voxeljet are precision machines for producing models that require absolute attention to detail and a precise representation. The VX1000 generated the oversized bowl in plastic directly from CAD data using the so-called layer building method.
It took approximately 10 hours to create the entire model from thousands of micrometre-fine layers, which were selectively glued together with a binder. The large build space of the machine made it possible to print the bowl in one piece with the dimensions 850 x 416 x 192 millimetres and a layer thickness of 0.15 millimetres.
Considerable cost savings thanks to 3D printing
The unpacking process, during which excess material is removed from the model, was followed by a stiffening process using artificial resin, and subsequently by the finishing that completed the PMMA bowl, which was then used as the original model.
This process did away with the elaborate construction of a negative mould, resulting in significant cost and time savings. The printed PMMA model, which impressed with a high degree of mechanical stability and attention to detail, was used to quickly generate a sand mould that was cast in bronze.
Subsequently the bowl was finished and coated with nickel, and finally attached to the spoon handle, which was made of brass and also coated with nickel. "The WMF spoon is another successful example of the ever increasing popularity of 3D printing beyond conventional application areas. We are really impressed with the creativity shown by users in applying 3D technology, which is still a fairly young method", says Rudolf Franz, COO of voxeljet technology GmbH.
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