Strongbox

thingiverse

I created a strongbox as a project for kids to assemble with plastic tools. Designing it was done using 123D Design and Tinkercad. Two Zip files contain STL files - one for a large strongbox that is 280 mm long, and one for a small one that is 160 mm long. The files are also listed individually. I chose the large strongbox size (280 mm) to fit within an FLSUN i3 (300x300x420) printer's limits. Using Tinkercad, I scaled down the large strongbox to produce the small (160 mm) strongbox design for smaller build volume printers. I have only printed the large strongbox, but the small one should print just as well. A small wrench is included to tighten and loosen bolts. If using the wrench, avoid over tightening and twisting off bolt heads. The bolt heads are roughly 20 mm across the flats - the wrench is about 22 mm for a loose fit. I designed the wrench using Tinkercad. The bolts and nuts used in this project were designed using NUT JOB – Nut, Bolt, Washer and Threaded Rod Factory by mike_mattala (www.thingiverse.com/thing:193647). An exploded view assembly drawing is provided to show how the parts fit together. Each strongbox requires 27 bolts: 20 – 17x11mm bolts for the top, bottom, ends, and front corners 6 – 20x11mm bolts for the back hinges 1 – 25x11mm bolt for the front hasp The bolts, hinges, connectors, and end pieces are the same size for both large and small strongbox designs. All hinges should be printed with the narrow edge against the build plate and using a 3 mm brim. I found this worked better when cutting away support material to enable the hinges to rotate. Be careful when cleaning up the hinges to avoid breakage.