Large gear ratios using Legos

Weird space heater! It would be cool to put another high efficiency motor on the other end and spin that side the opposite direction, spin them both real fast until they starting glowing at each end. Wrap a thermostat loop around it and use it to heat your living room. Probably would need some kind of active lubrication system to keep it from seizing up

Er, it won't turn from that end, what I mean is rather have two reductions starting from each end that meet in the middle

used 10,000 hand-made nails to define it's gear ratios. It only goes out to Neptune so your have to wait 29 years for a full rotation. Uranus was discovered at about the same time that Eise Eisnga finished his planetarium, so it's not included in the model. He'd have had to wait even longer for Lego.