Welcome to Paddleducks..... The home of paddle steamer modelling enthusiasts from around the world.
The way I make paddle wheels can be seen on this site. Construction, Duke of Devonshire, page 4&5.
I see that you are using the same model of smoke machine as I am.After I received mine, I modified it to hold more oil and it now runs well over an hour. I found a plastic box in my attic that was the same height as the steam machine.I carefully drilled a small hole into the side of the machine and the box as close to the bottom as possible and joined them together with a plastic tube. The level of the liquid will be the same height in both containers.Enclosed are two photographs.