The Chain Experiment is an annual competition which originated in Slovenia in 2005 and later expanded to Poland in 2013. For the purpose of the event, each participating team designs and builds a contraption that transports a small steel ball from one end to the other. At the same time the constructed machine needs to use a number of interesting phenomena and physics laws. In the competition’s finale, all contraptions are connected to each other to form a long chain transporting steel balls. In brief, they are all evaluated for qualities such as: creativity and advance in theoretical background, as well as the reliability of the constructed machine to work without human help. In this article, we present the contraptions developed by students taking part in the competition in order to demonstrate the advance in theoretical basis together with creativity in design and outstanding engineering skills of its participants. Furthermore, we situate the Chain Experiment in the context of other group competitions, at the same time demonstrating that—besides activating numerous group work skills—it also improves the ability to think critically and present one’s knowledge to a broader audience. We discussed it in the context of problem based learning, gamification and collaborative testing.

This research focuses on thermal deformations of thermoplast during three-dimensional printing. A filament acrylonitrile butadiene styrene was used, and the main focus was put on warping. Twenty-seven cuboids divided in six categories by their length, height, surface area, color, nozzle temperature and bed temperature were printed by Fused Filament Fabrication 3D printer. The whole process was captured by a thermal camera and the movies were used to analyze the temperature distribution during printing. All printouts were measured and scanned with a 3D scanner in order to highlight any abbreviations from the original digital models. The obtained results were used to formulate some general conclusions on the influence of selected parameters on the warping process. Based on the outcomes of the study, a set of guidelines on how to minimalize warping was proposed.

In studying the dehydration of surface-moistened fumed silica Aerosil powders, we found a conductivity percolation transition at low hydration levels. Both the percolation exponent and the threshold are typical for correlated site-bond transitions in complex two-dimensional (2D) systems. The exponent values, 0.94-1.10, are indicative of severe heterogeneity in the conducting medium. The surface moisture at the percolation threshold takes on a universal value of 0.65 mg([H2O])/m(2)([silica]), independent of the silica grain size, and equivalent to twice the first hydration monolayer. This level is just sufficient to sustain a quasi-2D, hydrogen-bonded water network spanning the silica surface.