The parts can be drops or odd gears and gnomish tinkered-looking stuff around the landscape. They tend to be found along the base of constructed walls and are hard to spot in low-rez or when too far in 3rd person. You need 8 pieces. The harvestable gears will refresh, given enough time.
Reported harvest locations include:
1386, 406, 755 - right by the opening next to the animal pen in U.J.L. 1.0