Years ago, before the major advances in custom tooling and gaging, it was common for homeowners to fiddle with their tools and gadgets to make minor adjustments and repairs on a mechanical level. In fact, this was a pretty indispensable skill not too long ago. People frequently repaired their vacuums, blenders, coffee machines, power tools, lawnmowers, and other home appliances. So what, exactly, needed repairing on these devices?