Steam engine train whistles have been in place on locomotives since the 1830s. Proven to be the easiest and loudest way to signal the approach of a train, the steam whistle is inexpensive to make and can be heard over great distances. Basic metal cutting and soldering are needed to fabricate a homemade steam whistle. Many model train advocates choose to purchase or construct their own steam whistles to be fitted to their model trains.
Flatten a small section near one end of the brass tube with the pliers. Cut a small, rectangular hole in the flattened area with the Dremel cutting wheel. This hole should be approximately 1/4 inch by 3/8 inch. This will be the mouth of the whistle.
Bend the side of the mouth closer to the long end of the whistle up into the hole on a sharp angle. File the edge of this lip so it is sharp on the end.
Insert the small scrap of flat brass into the mouth hole and line it up with the side of the whistle opposite the mouth. Leave a small gap between the mouth edge that is not filed sharp and the scrap piece. Solder the scrap to the inside of the whistle.
Flip the whistle over so the mouth is facing down. Drill a small hole using the small drill bit on the opposite side of the mouth between the scrap of brass and the end of the whistle. All the work done on the whistle thus far should have been done on the same end.
Place the small brass tube over the drilled hole and solder in place. Solder the other side of the small brass tube to your steam source.
Test your whistle by blowing into it before attaching it to the steam source. If the whistle does not make sound, try adjusting the filed angle of the mouth.
Use caution when handling the sharp parts and when the whistle is attached to the steam source.