Coach’s Whistle

I have volunteered for a chainsaw team. We will be volunteers cleaning up after storm damage. Members of the group need a coach’s whistle to get the attention of other team members over the noise of chainsaws. In this Instructable I worked out how to make these whistles at home in a way that is reproducable.* (I know one can buy them, but this is also a fun project to do with a grandchild.)

*I wanted to make several of these for a group. When I placed the unfinished whistle between the bases of my thumbs to test it there was a very good whistle sound. But, when I held flat pieces of sheet metal against the sides of the whistle I heard only the rush of air. That suggests to me I need to make the body of the whistle narrower, perhaps no more than 3/4 inch. See coming steps.

Materials

• 3/4 inch electrical conduit
• steel sheet about 16 gauge

Tools

• Metal saw
• Rule
• File
• Grinder
• Wire feed welder (MIG or Flux Core)
• Clamps
• Pliers
• Hammer
• Vise
• Scribe
• Wire wheel

Cut a piece of metal tubing to 7/8 inch in length. The tubing should be about the same diameter. Electrical conduit works well. You may even make your own tubing by forming flat stock around a piece of pipe.

Cut out a piece to leave a gap of 1/4 inch. The gap should not be less than 1/4 inch. See the second photo. Grind or file a chisel edge on one side of the opening.

Cut a piece of flat sheet metal 7/8 x 1 inch for the bottom of the mouthpiece. The photo shows the body of the whistle with the chisel edge away from the mouthpiece. The body of the whistle is against a piece of scrap wood. Also against the scrap wood is a 1/8 inch spacer. Against the spacer is the piece for the bottom of the mouthpiece. A line extended from the top surface of the mouthpiece should pass 1/16 inch under the chisel edge on the opening.

Tack weld the bottom of the mouthpiece to the body of the whistle. Ideally, the weld is in the acute angle where the mouthpiece meets the body. In reality, some of the bead is mounded up on top of where the two pieces join. It can be ground later to provide a flat surface for welding the sides to the body. (I have my welder set up for flux core wire rather than gas shielding.) Once the bottom of the mouthpiece was tacked to the body of the whistle, I welded the other side of the whistle. Because the tack weld kept everything secure and immovable, I was able to weld in the acute angle between the mouthpiece and the body. A couple of tack welds are all that is needed.

I put the piece for the top of the mouthpiece into a vise and allowed about 3/32 inch to extend above the vise jaws. Then I used a hammer to pound that over to form an “L”. See the second photo. I used a scribe to mark the width of the mouthpiece. My vise jaws were not too high from top to bottom and I could put the piece back into the vise to fold the second edge over. See the third photo. I tack welded on the right side of the mouthpiece as seen in the photo. Note the overhang on the left side. I cut that away before welding. Then tack weld the left side, too. Note: The steel becomes too hot to touch during welding and grinding. I waited several times for it to cool. I also wore welding gloves.

Grind or file away rough edges that can cut or scratch your lips. Notice the path of air through the mouthpiece comes just barely under the chisel edge on the whistle opening. See the second photo. Lightly press the base of your thumbs against both sides of the whistle’s body and blow through the mouthpiece. If you do not hear a sharp loud whistle sound, check to see that the opening is 1/4 inch wide. You can also bend the angle of the mouthpiece just a little so the parts align as in the first photo. In the second photo the right side of the chisel edge is a little higher than the left side. The whistle worked fine, but I made a minor adjustment for the sake of appearance.

Cut a square of sheet metal to cover the side of the body. Grind or file where the mouthpiece meets the body of the whistle as needed for a pretty good fit on the side. Tack weld around the four edges of the side. Trim away excess. Grind the body of the whistle smooth. Test the sound of the whistle but pressing your thumb against the open side and blowing. Repeat the process for the remaining open side. Test the sound ofthe whistle.

This is how my whistle looks when nearly finished. It makes a loud sound that takes my wife by surprise if she is not expecting it.

I added a loop for attaching a lanyard. I positioned it according to where my hand fits on the whistle when I grab it to use. It is from a piece of steel scrap. I simply bent the scrap into a “U” and welded it. Then I polished the whistle with a wire brush wheel.

I did not add a small spherical object inside the body to make the whistle warble rather than give a steady tone. You may do that, but it will need to be very light in weight. I dropped a glass bead through the opening, but the bead is too heavy to be carried by air currents, so there was no warble. A plastic bead might work, but it should be large enough that it cannot fall out. You can either place it inside the body before you finish welding and be careful that it does not get too much heat, or you can try to compress it and pass it through the opening.

I have thought about the person who does not have access to a welder. I am sure someone could make these whistles with 3D printing. (I have no experience with it.) I think it would be possible to make one of these whistles from steel and use an epoxy, like JB Weld to join the parts. Some metal tabs where needed could be part of the way pieces are cut. Or, I once made adapters to fit AAA batteries into a charger made for AA batteries. The adapters were made from paper smeared lightly with carpenter’s glue. When the glue dried the adapter was quite strong.