Cycling, which has many enthusiasts not only in the Czech Republic, is full of innovations that are often associated with 3D printing. Design prototypes of printed bike frames, scooters and other selected components are not missing at trade fairs and conferences. However, far fewer projects make it to mass production. The typical reason for this is usually too high production costs, sometimes the path to the market is hindered by a limited choice of materials, but often inexperience in implementing additive manufacturing in real life can also be an obstacle.
In the overload of information (and misinformation) about 3D printing, it is useful to find an expert consultant - a development partner who is familiar with the issues and can help with the implementation of projects where additive technologies play a significant role. That's why start-up Posedla turned to 3Dees Industries, a company that helps with the use of industrial 3D printing not only for prototyping, but especially for manufacturing purposes.
In the beginning, the idea was to produce bicycle saddles tailored to each person's buttocks. Customized production is perfectly compatible with 3D printing, so the plans of Martin Řípa and Jiří Dužár from Posedla were clear up to this point. "We knew that additive technologies would allow us to achieve our goal much faster than developing using the classic method of lengthy and costly modelling, production using conventional methods and subsequent testing," explains Martin Řípa. František Hůla, an application engineer from 3Dees Industries, took on the project and focused not only on the application of the appropriate technology and material for production, but also on the downstream manufacturing processes.
From the perspective of additive technologies, the individual obstacles on the way to market were overcome one by one. In the case of the material used, it soon became clear that the initially intended inflexible polyamide would be replaced by the much more suitable elastomer TPU. 3Dees Industries prepared prototypes of the elastomer by means of the Multi Jet Fusion (MFJ) technology on professional HP Jet Fusion 5200 3D printers, and the actual saddle design was rapidly approaching its final form. The key segment of the saddle is the upper 3D printed lattice (grid) structure, which is highly flexible and ventilated. The correct stiffness of the structure placed on a carbon base is the result of a series of print tests and testing with Posedla's other R&D partners.
The final design was shaped during many joint sessions, which resulted in suggestions and recommendations from the development partner to optimize the mesh, the construction of the model and also the concept of an insertable customizable element in the back of the saddle, the so-called "insert", which makes each saddle unique. This feature, which is included in the saddles currently in production, could be popular with customers and differentiates Posedla from many similar projects around the world. The next step was to fine tune the so-called post-processing. That is, modifying the printed part so that the saddle does not absorb water or sweat, is more durable and washable. The chosen process, called vaporization, which seals and smooths the surface of the lattice structure, proved to be a successful one, and the 3D-printed part could be prepared for mass production in this way.
The consultancy does not only include solutions in terms of the final model, its mechanical properties and technological recommendations for production. It is equally important to clarify in advance whether additive manufacturing makes sense from a cost perspective. The company always looks at whether it is worth investing in moulds or manufacturing using other traditional methods. In the case of complex lattice structures, product customisation and fast delivery to the client, 3D printing was the only possible solution. From the beginning, it was clear to Posedla's founders that they would be offering a premium product.
Nevertheless, it was necessary to calculate the costs of mass production in advance, from print preparation and production to post-processing. 3Dees Industries prepared a detailed cost analysis of additive manufacturing for this purpose. "We wanted to give our clients enough information so that they could make their own decision whether to purchase their own technology in-house right from the start or rather work with an experienced partner for custom production first," explains František Hůla.
One of the many other challenges that had to be addressed, even from the point of view of ease of production, was working with the input data for 3D printing and its so-called "nesting". This was about stacking models and achieving the maximum number of pieces that could be produced at one time in the print chamber. Also important is the orientation of the 3D models, which can affect the resulting rigidity of the lattice structure.
Another point to address was the data volume, as a single saddle model can be up to 100 MB in size, and if there are, for example, 40 models in a single build, it will put an extreme strain on computer performance. A concerted effort to optimize the network has realistically reduced the data volume to about 40 MB, and they are not done yet.
One of the basic principles that 3Dees adheres to is that there is no need to overload the 3D model with details that the printer cannot print anyway, and yet they do not affect the function. For example, a higher level of detail only needs to be maintained for view surfaces, and a functional lattice structure can have a coarser resolution.
The final step before production could start was to clarify the entire production workflow, both in terms of hardware and software, and the error-free sharing of data between the different entities. As the above cost analysis of additive manufacturing showed, Posedla planned the actual printing with an external partner, namely One3D, which has sufficient production capacity on HP Jet Fusion 3D printers and post-processing facilities.
Currently, the project is already at the stage where anyone can order their unique bike saddle from Posedla. Production has successfully started. But the development partnership is far from over. 3Dees Industries is pursuing the development of new production processes as well as new material options and possible further post-process modifications. Currently, a new wave of proofing prints are being discussed against the first batch in production. Thus, work on further product innovation continues after the product launch, and the developers' ideas are continuously tested and compared with actual deployment. If the Posedla is indeed sold en masse, it will be worthwhile for the company to stop outsourcing production and buy its own additive technologies for mass production. Here too, 3Dees Industries can be of great help, because in addition to all the listed competencies, it can also help with financing solutions for 3D digital production.
"The cooperation with Martin Řípa and Jiří Dužár was very stimulating. Both parties take a lot of experience from it. We are glad that we could be at the start of the project of another successful application of HP Multi Jet Fusion additive technology, which is currently the best for the production of final parts," concludes Ondřej Štefek, Managing Director of 3Dees Industries.
Photo source:: Posedla
Photo source:: Posedla
