Both grandfathers died before I turned 16 years old. Both men were very interesting.
Maternal grandfather: Master tool and die maker who had a complete machine shop in his basement. Using his machine shop, he built a small scale (about 4 feet long) live steam engine that was strong enough to pull ten men around the little live steam track near Vancouver BC. He made every wheel, bar, screw, the boiler, and part in his basement. The locomotive now resides in a museum in near Vancouver BC.
Paternal grandfather: was really good at growing things. He had a pear, apple, cherry, plum tree in his back yard, but he had grafted different fruits onto each tree so that each tree produced four varieties of the same fruit. (4 kinds of apples, 4 kinds of pears, etc). We used to get to pick which fruits we wanted when we went to his house.