Page 57 - FDMAsia JulAug 2024

DESIGN 55
www.fdmasia.com | FDM ASIA JUL/AUG 2024

machines expanded to perform multiple tasks simultaneously, place by means of magnets, but rather screwed into the edges.
meaning that they constitute multi-purpose tools to execute Based on the intended modes of use, we performed three
complex operations at a time on the same location. The basic testing cycles, assuming that the cubes would not be
advanced five-axis machining then facilitates fabricating even permanently employed to function as seating furniture. The

the most demanding forms and shapes. tested product was equipped with a cushion and metal gliders
Considering the furniture presented in this article, suitable sized D20 × 7 mm; the gliders were fixed to the bottom with
resources comprise solid wood or plywood. In these materials, magnets.
however, CO2 laser cutting results in surface soot deposits and Alternatively, the cube was subjected to testing together
dark edges; such spots subsequently require refining (grinding). with the baseline version, the assumption being that the
To process the main plywood panels, we therefore products would also be utilised as stools.
employed a CNC miller, obtaining smooth edges. The PUR All of the test cycles were executed at a dedicated laboratory
foam elements, namely, the M-shaped letters, nevertheless for joinery products and furniture, accredited according to
did not show any burns or dark stains. Overall, the CO2 laser the Czech Republic standard ČSN EN ISO/IEC 17025:2018;

method offers major advantages, including but not limited the facility is operated by the Faculty of Forestry and Wood
to clean machining, low noise, high precision, fine detailing, Technology, Mendel University in Brno.
effective engraving, and fast operation (at speeds of around
500 mm/s). Stability Testing
Further, we utilised fused deposition modelling-based 3D At the first stage, we carried out stability tests in agreement with
printing, the device being an Original Prusa i3 MK3S printer the Czech standard ČSN EN 1022:2020 (Furniture—Seating—
(manufactured by the company Prusa Research, the Czech Determination of stability), art. 7.3.1 (Forwards overturning);

Republic, Prague, Czech Republic). the standard covers seating furniture for all locations and
The individual concepts proposed by the customer were types of application.
analysed and extensively consulted. In the procedures, the load on the seating surface at the
The source materials, i.e., furniture grade birch plywood distance of 60 mm from the edge of the supporting structural
(multiplex), polyurethane foam boards, corn starch-based PLA board amounted to 600 N, and the applied overturning force
filament, and neodymium magnets, were then selected upon was 20 N, both applied as per the standard.
the analysis of the submitted customer requirements. Outcomes: The product was not overturned by the relevant

Laboratory Product Testing

The cube with perforated side walls was subjected to testing,
due to the product’s structure and bottom gliders being different
from those of the original baseline model.
Compared to this initial version, the tested cube does not
include a centre part but its inner space is enclosed with walls
on all sides; the side boards feature M-shaped openings; no
bottom board is used; and the structural joints are identical

with those in the prototype, including the plastic corner edge
elements. Further, in the tested item the gliders are not held in