Round hole through a second floor to the first

[hdewerth]

Is there any easy way to make a round hole through a floor. I want a hole from the second floor to the first. (Actually a 39" diameter hole for a pneumatic elevator) I was able to make a rectagular hole & fool with it as a polyline but it seems there should be a straightforward method for placing a round hole through the floor. Maybe a firehouse designer out there knows. Suggestions appreciated. Looked through all the documentation but didn't come across and simple answer.