Roller skate bearings. | Model Engineer
1 articles A place where I worked in the 70's had quite a lot of sets of radio gear that used a quite nice fan with a machined alloy case and blades to suck the hot air out. The trouble was that they chopped out the bearings quite frequently. One of the bosses had a son who was into speed skating at the national level. Whenever we found a fan that had gone noisy, we would change out both the bearings and put in new ones. The old ones had to go to the boss guy so that he could put the OK ones into the skates, since they were the exact same size. Usually only one bearings had actually failed, y...
Source: model-engineer.co.uk