Creating Functional Prototypes
with Multiple Materials


Creating Functional Prototypes with Multiple Materials






International manufacturer of metrology and inspection technology. Founded in 1932, the
family-owned business today employs more than 150 employees in its headquarters in Bad
Wünnenberg and outside of Germany.


Creating a looks-like, works-like prototype to prepare a new product for casting and manufacturing.


Using Form 2 stereolithography 3D printers and two different engineering materials,
Wöhler produced a high-quality casework and flexible keypad for a functional prototype
in-house, substantially faster and at a lower cost compared to FDM printing and molding.


  • 70% reduction in lead time, from 1 week to 2 days.
  • 75% cost reduction in prototyping.
  • In-house 3D printing allowed Wöhler to test with a precise functional prototype,
    lowering molding and manufacturing risks.


Wöhler, an international manufacturer of measuring and inspection technology, makes the Wöhler HF 5500 wood moisture meter, an instrument that measures the moisture in firewood and wood products like pellets and wood chips. During the development of the HF 5500, Sebastian Leifels, a product designer at the company, was responsible for designing and fabricating a prototype that looks and functions just like the final product, before moving the project into molding and
final production.

“This stage of the design process is extremely important to prevent mistakes later on in manufacturing. Changes to the injection mold as well as the end product are expensive. The costs range from a three-digit up to a five-digit euro figure.”

At the beginning of the design process, Leifels used a fused deposition modeling (FDM) 3D printer in-house. However, the FDM printer was not able to produce the accurate details needed for the casework of the device or the flexible parts for the keypad.

With high-resolution stereolithography (SLA) 3D printing, Leifel and his team were able to produce a functional prototype with two different materials for a quarter of the cost compared to FDM printing, savings weeks in lead time.

Product designer Sebastian Leifels kept production in-house as he created a looks-like,
works-like prototype for the Wöhler HF 5500 Wood Moisture Meter.


The prototype for the moisture meter required several different materials; however, the precision wasn’t good enough to reliably test it with internal components and electronics. The machine was also unable to print flexible parts, which meant Leifels needed to go through a complex process of designing a mold for casting, printing it on the FDM printer, casting the flexible parts in the mold, and painstakingly post-processing the part to smooth the surfaces.

“This was a time-consuming process and we were still unable to provide fine details. Now, we have simplified our process by producing direct prints of detailed parts on the Formlabs 3D printer.”


To meet his deadlines, Leifels had to quickly iterate on his prototype. To do this, he chose the Formlabs Form 2 3D printer, which uses stereolithography (SLA) technology to create precise models within hours.

“With the Formlabs desktop 3D printer, the prototype production was reduced from several days to a few hours. By producing various parts and the housing on the printer, we saved several weeks in the entire development process.”

Leifels and his team used Formlabs Black Resin for the case and Flexible Resin for the keypad. The keys had to compress when the user pushed them, which required the keypad’s walls to be very thin but durable. Using the FDM-printed mold and casting, achieving this level of detail would have been impossible. Assembling and finishing the prototype only took another day,
whereas the prototype would have taken one week using the previous combination of FDM 3D printing and molding.


Prototyping on the Form 2 enabled the Wöhler team to increase control and speed in the design process. Leifels ran the printer day and night for several weeks during the development phase, and was able to produce all crucial elements of the prototype within a day. With the capability to create more prototypes in materials that closely match the properties of the final product, the
team was able to spend more time testing new ideas and iterating toward the perfect design.

“3D printing in-house with functional materials such as Flexible Resin allowed me and my team to conduct a range of tests with the prototypes without any damage or functional constraints of the part. With the Form 2, we have the advantage of testing the parts for each device before mass production. The risk of reworking the device later is low.”

Using a single machine that produces multiple materials has opened up new prototyping possibilities for the Wöhler team. Prototyping on the Form 2 has not only saved the team time and money, but helped them create better final products.

Using Formlabs 3D printers, Wöhler has shortened lead times for its functional prototypes by 70 percent, and achieved 75 percent cost reduction.


Formlabs Form 2 Desktop Printer
Formlabs Grey Resin
Formlabs Flexible Resin

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