A lot of musical instruments come to mind. Also many plumbing related things in a house such as faucets, temperature shutoff valves, toilets. Manual kitchen g

A lot of musical instruments come to mind. Also many plumbing related things in a house such as faucets, temperature shutoff valves, toilets. Manual kitchen gadgets are usually pretty simple but still interesting. Peelers and slicers, pasta machines, oil expeller, scales.