Low cost molecular models production with digital modeling and fabrication

Digital fabrication toais like 30 printing and computer controlled laser cutting are new and exciting ways to create classroom resources. These technologies are not accessible to teachers due to the high cost of the machines and the need for computer design software (30 and 20). Makerspaces are a way to have access to these machines ata reasonable cost. We used SENAl's Laboratório Aberto makerspace in Belo Horizonte for the production of molecular models for classroom use. Our first option was to use a 30 printer and to create the 30 file in a free, easy to use, online software called BlocksCAD. Two "atom" models were printed (Figure 1 ), one a 120 degree connector for the making of a fullerene model (type 1 ), and the other a tetrahedral connector to representa carbon atom in other molecules (type 2). Only one of each of the two models was printed for testing (R$ 15). A second alternative was tested to lower the cost of the model, using a laser cut machine and 3 mm MDF board. The 20 contour file for cutting was made in an illustration software. One 60 x 90 cm board costs around R$1 O and allows for the cutting of at least 450 type 1 or 300 type 2 connectors (Figure 2). A fullerene model with 60 atoms connected by plastic straws is shown in Figure 3. The fullerene model costs less than R$10 (US$3) to make.