The other son builds a machine.

It's a profit machine, but it is very hands on.   

The trick is to only gamble when you're the house ... and not the poor sucker on the slot machine. 

You rarely gain, sometimes you might win, but you always loose your time sitting on those stools in front of a boring machine. 

Fear of what MAY happen had taken over the machine.

My kids are way better than me at Fortnite.Overwatch is what I play a lot of online while working out on the elliptical machine. 

What's the cost of insurance if you're allowing renters/guests to use the machine?

YOU need them to keep your machine working.Your guys also know your going to pay them.This is why so many rehab guys want money up front ONE they can't afford to not get paid basically weekly as there life runs on weekly pay checks.. and two they don't have accounts at the suppliers IE CREDIT... so they are cash and carry..

I would stay away from heavy floor paints( or thin it a bit). if your unit does spray you will want a storage liquid to put in after first use and every use there after.You dont want paint to dry inside your machine, you want to keep everything on the inside submerged and wet. 

There are exceptions like Chris Clothier's well oiled machine but in the main I just don't get it.