Let see, a full lane length, from the foul line to the end of the pin deck is 62 feet 10 and 3/16 inches long. The approach is 15. You need a 5 foot (min.) access behind the pinsetter (per Brunswick specs) and the pinsetter itself will be 2-3 feet from the end of the pin deck.
I'm going to concur with the previous posts and say plan on around 100 feet (assuming that this is for like a home install, otherwise you'll need a longer building for things like a front desk, snack bar, arcade, bar, etc.)