## 4 Discussion  
The testing procedures showed that when gliders are mounted, the cube tends to partially yield to the applied force in that it leans on the bottom edge of a structural board (Figure 15a); nevertheless, total overturning does not occur, as already indicated above. Figure 14: The impact testing: (**a**) before the action; (**b**) applying the force. Source: the authors (2023). Figure 13: The tests: (**a**) static loading on a preselected spot; (**b**) overall static loading. Source: the authors (2023). In this context, it is then somewhat problematic to determine clearly whether the product conforms to the standards. If tested without the gliders, however, the cube exhibits superior stability, satisfying all the requirements (Figure 15b). Similarly to the images in Figure 13a,b, the graphics in Figure 16a,b below represent the load and impact tests; in the latter figure, however, the testing is performed on a cushioned cube. The obtained results confirmed the structural strength of the cube and also led to a modification of the glider mounting in response to the ambiguous overturning performance; presently, the gliders are embedded in countersunk seats and protrude beyond the surface line by 2 mm at the maximum. Another alteration lay in the gliders being fixed to their seats with screws in place of the magnets used in the initial versions (Figure 10a,b). In furniture, a significant parameter rests in the carrying capacity. To verify this property, we first set up a standardized stability test to load the seating surfaces with a weight of 600 N at a distance of 60 mm from the edge of a main structural panel; such a configuration represents a force of 61 kg. Figure 16: The load and impact tests: (**a**) static loading; (**b**) impact action. Source: the authors (2023). Figure 15: The stability testing: (**a**) with the gliders; (**b**) without the gliders. Source: the authors (2023). The measurement process and its outcomes confirmed that the product satisfies the requirements on children's furniture in terms of the structure, ruggedness, and stability. The firm fasteners are completed with plastic, 3D-printed edge joints to provide a load capacity of between 150 and 200 kg; thus, the capacity limits for the targeted age group do not need to be estimated. Regarding the physical and safety attributes, the product is well-conceived, combining a glued structure with reinforcing plastic corner elements; in many cases, these edge parts exhibit superior strength values, as also emphasized by [PERSON] et al. [34], who examined the parameters that exert an impact on furniture safety. By a more detailed definition, the researchers focused on the impact toughness testing of samples integrating 3D-printed plastics (PC-ABS; PC) with adder tree wood; the printed elements included structural joints in particular [34; 35]. From the utility perspective, the cube was assessed in terms of whether its use by pre-school children can be regarded as safe. The set of monitored sectors involved, among others, the openings milled in the panels to accommodate the [PERSON] letters; in this context, we reviewed the size of the gaps to avoid children's fingers getting [PERSON] and, subsequently, hurt or broken. Furniture safety is generally provided for in the Czech Republic's Act no. 102/2001 Coll., on General Product Safety [32], and standard CSN 91 0100 Furniture--Safety requirements [33]. A product designated as safe must comply with specific national and international legal regulations; where no such regulations are in force, the attribute of _safe_ shall denote any product that satisfies the Czech technical standards and/or expresses the state of the art at the time of being introduced to the market [50]. Overall, regarding the concept, functional capabilities, and safety, the furniture set designed within our project may be compared to items such as the multi-purpose Montessori cUbe series [51] and the Whitney Brothers Play House Cube [52].