Suppose it was possible to drill through the earth side to side with a hand drill, what would the digger experience as he digs?

As he approaches the core of the earth, would he start to feel weightless? I dont get how his perspective can change from digging down to digging up, it just doesnt settle with me. Does physics have a way to accurately explain what a person doing this would experience?

At which point does his orientation flip from digging down to digging up?