calottes (zip-Datei)

This is a 3D print file for dome models of pentane isomers. The calotte model is a three-dimensional representation of molecules in which atomic sizes, bond lengths, and bond angles correspond to real proportions. The models support the exploration of structure–property relationships in chemistry lessons, particularly when studying hydrocarbons in introductory or lower secondary education. The models were designed and tested as part of the 3D4VIP project. Printing instructions and tips: Each calotte consists of two files, one representing the carbon atoms and the other the hydrogen atoms. In the slicer, both parts are assigned to different filaments for a two-colour print and then merged into one model. Two variants are available: a half-model that requires two printouts to form a complete molecule, and a full model that consists of top and bottom halves printed separately and later glued together. The halves are printed as hollow shells without infill and aligned using spacers for accurate assembly. Print settings depend on the slicer used; the models were mainly tested with Ultimaker Cura. For the calottes, adaptive layer height, make printable, and brim options should be disabled. The initial bottom layer should be set to zero, wall thickness to three layers for carbon atoms and two for hydrogen atoms, and infill to zero to keep the shells hollow. Standard settings can be used for the tetrahedrons and spacers. The STL files contain the individual halves, while the 3MF files include the combined partial models with both atom types.