FERMIhack

thingiverse

The FERMIAC is a mechanical computer from the 1940s, used for running Monte Carlo simulations of neutron transport inside nuclear reactors. I want to build one. You can find full information at my Hackaday.io project page. More updated versions of these files may be available on my GitHub page. Print Settings: Printer Brand: Type A Machines Printer: 2014 Series 1 Rafts: No Supports: No Resolution: 0.4 Notes: Wheels, thumbscrew and pt 2 of both drums were printed with ~20% infill. Pt 1 of both drums was printed with 0% infill and 3 layer walls, this was required on my printer to get the thin wall at the top of each part to form. I used PLA at 220C with a glass heated bed at 70C, no additional adhesion. Minor cleaning was required to remove stray plastic from the shaft holes and bearing pockets. Post-Printing: Assembly Additional required parts: 8x M3x12 bolts 1x M3x16 bolt 4x M3x6 bolts 13x M3 nuts 4x M3 washers 2x 91mm M3 or 3/16" smooth rod 2x 97.5mm M3 or 3/16" smooth rod 2x ~110mm lengths of thin wire 6x ~1" OD O-rings to fit drum & wheel grooves Glue Tape Assembly instructions: Affix both acrylic parts to side panels with medium bolts, see orientation from DXF. Glue wide strut with center hole to front position of side panels, attach thumbscrew through center hole with long bolt and nut. Glue drums pt 1 and pt 2. Install drums into frame (see DXF for orientation), slide short smooth rods through side panel holes to pin. Use tape on side panel to secure rod. Affix arms to side panel with medium bolts. Glue arm struts. See DXF for orientation. Install wheels into arms (see DXF for orientation), slide long smooth rods through arm holes to pin. Use tape on arms to secure rod. Thread washers and short bolts through holes at tip of arms and affix. Wrap thin wire around bolt and tighten to hold read-line in place. How I Designed This: This design was made possible by the Bradbury Science Museum in Los Alamos, as well as Fabrizio Coccetti, senior research technologist at the Enrico Fermi center in Rome. The following two papers were consulted during development: http://www.sif.it/riviste/ncc/econtents/2016/039/02/article/24 http://static.sif.it/SIF/resources/public/files/congr15/mc/Coccetti.pdf