1. Glue a little piece of bendy straw to the bottom of the valve. Glue a long straw to this for the steam line.
2.Glue the valve to the hole in the side of the cylinder.
3. Put the valve plug in the valve and slide the straw on the valve stem onto the crankshaft.
5. Make the straw for the valve stem longer or shorter so that the plug is just next to the straw on the side of the valve when the crank for the valve is halfway up or down (like it is in step 3).
6.You are the boiler! ! ! ! ! ! ! Just blow! ! ! ! ! ! ! Or you can make something like this to hold a balloon. Then the balloon is the boiler.