Could be fun and certainly educational to use LEGO to construct the early mechanical calculators? Probably some patents come in the way, but maybe a lego original, construct the primitive arithmetic operations and put together. And why not ciphermachines out of LEGO
Building horology clocks out of LEGO do not seem that impossible, of course they would hardly last half a millenia, but a little plastic with siliconcoating goes a long way, and if you could make the gearwheels out of carbon fibers, they would probably outlast the ones of metal. http://www.suspart.com/news/carbon-fiber-gear-wheel-research
What would be real fun a shaft and gear wheel emulator where you just throw out 3D gearwheels on a sheet tell how many tooths, resize them with mouse or fingers an outofit function to make them connect. Build your own watch emulator ;D
It also would be nice if the gearwheel emulator did not fuck up at (Mathematica and wolfram) n tooths the infamouse n-tooths fuckup bug.
(monkey arithmetic soultion) n = -1???? for equation 0.49999999999= (n/2-1)/n
Because i can not stand bad arithmetic either in Mathematica, Wolfram or in engineering. Todays mathematicians a bit dunse i guess.