I've had the inclination to do this sort of thing, but the more hardware you have, the more likely, you'll have a component on some machine that will fail. As one person, you might end up spending all your time replacing or throwing away broken parts to keep the cluster up.

The other this is to pay for the electricity of a couple boxes running, regardless of how slow they are at a larger scale.

This sort of thing is good as a learning experience, imo, but if one's hoping to scale it up expect to run into lots of infrastructure problems one has to solve.