Rin is having a happy Sunday afternoon playing with her slot racing set.
"For some reason, the red Porsche is running a little slow ..."
"Nothing obviously wrong here ..."
"OK, let's put it on the bench for a proper examination."
"Take out a couple of screws, unbolt the main chassis and ..."
"... I see .. one of the brushes is a little worn. No problem to replace that."
"OK, all fixed, let's see how it runs."
"I can never get them to line up properly."
"Yesssss! Back to normal running speed, now we can have a proper race."