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38 TECHNOLOGY MAY/JUN 2024 FDM ASIA | www.fdmasia.com

Jonathan Borba seat, and a separate part to rest the legs. The final form after
manufacturing is shown.
In this case, the scanning time of all three parts takes
around two hours, the processing of all scans for all three

parts takes around five hours, and 3D modelling (reverse
engineering) takes an additional six hours.
The analyses of the dimensional precision for the legs
and seat are shown. The dimensional accuracy analysis is
carried out only on one side of the chair because one side
is scanned in 3D and another is created using the mirror
command during 3D modelling.
A dimensional analysis of the lounge chair seat confirms
deviations well below one mm, which is well within the

acceptable tolerances for furniture manufacturing.
It is important to note that for laminated wood components
pressed and deformed like this seat, achieving extremely high
After a visual and practical examination of the first prototype, dimensional accuracy throughout the entire structure might
the designer was not satisfied with the chair’s shape, look, not be necessary.
ergonomics, and practical aspects, so he used hand tools for The production process can introduce minor cracks and
grinding and polishing to create a new, modified prototype. delaminations. These imperfections are acceptable in this case,

The problem is that the latest prototype did not match the as the final product will be upholstered with soft material,
3D CAD models, so it was impossible to manufacture more effectively hiding them. In such components, dimensional
chairs with the modified design. It was necessary to 3D scan deviations of up to several mm might be accepted.
the new design and use 3D-scanned models to create new
CAD models ready for manufacturing. Case Study No. 2
A mainly blended command was used for chair legs, The second example of 3D scanning in the furniture industry
combining cross-sectional sketches and mirroring another is the case study where a 3D CAD model of an already
side. The CAD modelling is shown; the same method was manufactured chair part was needed.
used for the squat part of the legs. This is the case where it is necessary to reproduce the same

The 3D modelling began with standard surface modelling part, but the part does not have any technical documentation.
techniques applied to the raw scanned raw data (point cloud). In this case, the frame of the chair must be manufactured
This involved creating multiple splines across the scanned using welded pipes.
surface. The frame has complex geometry that cannot be measured
Next, a sweep command was used to generate the initial using traditional techniques (contact methods). This project
surface model. This surface was then refined by cutting it was supported by the Standard Furniture Factory (Ilija,
along the edges of the scanned data. Bosnia and Herzegovina). In this case, the scanning time,

Finally, a thickness of 10 mm was applied to create the scan processing, and 3D modelling (reverse engineering) took
solid 3D CAD model. This lounge chair comprises legs, a around one hour each.