My washing machine is making a weird noise during the spin cycle, what could it be?

Usually when a washing machine makes a weird noise during the spin cycle, it's because of something in the drum. The most common thing is that a coin, a button, or something small has gotten stuck between the drum and the casing. That makes a pretty annoying metallic knocking sound. It could also be that something inside has broken, like a drum blade or a motor part, but that's already more serious.

What I'd do is first stop the program and empty the washing machine. Then open the door and see if you can spot something obvious inside or around the drum. If it looks like something's trapped in the sides, try to get it out carefully (sometimes with tweezers). If you don't see anything and it keeps making noise when you turn it back on, you probably need professional maintenance because it could be that some internal component has come loose.

Another thing that happens is the bearings get worn out, especially if the washing machine is already old. In that case the noise is more like a constant buzzing during the spin cycle and tends to get worse over time. If that's it, yeah you'll need someone who knows what they're doing to look at it because changing bearings is more complicated. But before you spend money on a technician, try looking for loose objects first, because a lot of times that's what it is.