I designed lock-blocks a couple years ago including singles, doubles, triples & quads. I can share them in STL format if you're interested. The single is 29" square x 33" tall. The quad is a scale 118" long. They're also hollow (see the pics) so they can be stacked, though I've never actually printed them. So I'm not sure how well they'll print or stack once printed. But if you'd like to give them a shot I can send you the files. Either as individuals or I have a 60 piece set layout out in a roughly 3.4 X 3.5 inch pattern. No charge.
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