Pretty much what weed burner said, but it's not quite that simple. There is a big difference between a clutch that slips and a clutch that has a controlled amount of lock up. I can tell you had it been explained to me correctly in 1983 it would not have taken me another DECADE to figure it out. And I used to have a stack of broken parts to prove that I was slow on the uptake.
Do not mistake clutch slip with a controlled application of the pressure of the pressure plate with base and counter weight.
