To combat the slipperiness, special boxes for sand or salt are often placed along slippery slopes, such as bridges in winter. We used such a box for a new packing
...Plus problem. The goal is to pack the four polycubes in the box and shut the lid. Only the ingenious puzzlers will succeed and the others end at the bottom of the slippery slope.
For DIY printers, the STL's can be ordered by copying the following link in your browser:
https://np.works/2022/01/sandbox.html
