Trains are a going concern around our house, of late. A complicated network of wooden tracks crisscrosses our living room, so that safe navigation from one end to the other looks something like a game of hopscotch. Ensconced in the centre of this empire is a happy little boy, holding at least one train car in each chubby fist, and interspersing his technical descriptions of the cars with “chick-a-chick-a-CHOO-CHOO!” sounds. So, during a cold half-hour standing at the back end of an Ikea parking lot while my son frantically pointed at passing passenger and freight trains, “CHOO-CHOOing” his delight, the idea for an obvious gift came to me. “I should get him a train whistle… better yet, make a train whistle!”

Make a toy train whistle for your train lover: a fun DIY toy project that will delight kids!

My first thought was to make a version of the wooden block whistles I remember from when I was a boy. After a few minutes reading about whistle technology, though, I realized that a metal tube would work just as well as a cylindrical void in a wooden body, and might better visually suggest the age of steam that its sound conjures. With a general design concept and a few technical measurements, I headed to the shop. The project was a leisurely afternoon’s work.

Tools to Make a Train Whistle

To make the whistle pictured, I used the following tools. Alternative suggestions follow in brackets.

  • pipe cutter for cutting the copper pipes to length (or a hacksaw)
  • angle grinder with cut-off wheel for cutting slots in the pipes (Dremel cut-off wheel, Sonicrafter with hacksaw attachment, hacksaw, or a coarse file)
  • drill or drill press with 5/8″ and 1/4″ drill bits
  • lathe(there aren’t any of the parts I turned that couldn’t be made otherwise)
  • file
  • sandpaper

Materials to Make a Train Whistle

  • 2′ of 1/2″ copper pipe. Used for residential plumbing, it is easy to come by.
  • 2″ x 2″ x 6″ hardwood (it only needs to be 4″ long if you don’t plan to use a lathe)
  • wooden dowels: 1/2″ and 1/4″
  • polyurethane glue or epoxy glue

Tutorial on How to Make a Train Whistle

Make a toy train whistle for your train lover: a fun DIY toy project that will delight kids!

1. The length of each pipe is what determines its pitch, and the right combination of lengths will provide a pleasing harmony. Cut your copper pipe into four sections, 7-1/2″, 6-1/2″, 5-1/2″, and 4-1/2″. Ream or file the ends of the pipe so that there is no constricting bur left on the inside. The copper pipe can also be polished bright with a bit of metal polish and elbow grease. I turned my on the lathe to polish them, because I think elbow grease is over-rated!

2. Next, mark the notches to be cut in the copper pipe. They are the same on each of the four. The first mark is a line 1/2″ from mouth end of each pipe that passes half way around the circumference of the pipe. The next mark is 1/2″ further down the pipe, and is the starting point of a cut that will gradually deepen until it meets the first line.

3. Carefully cut the notches in the copper pipes. The notch will deflect a channel of air that flows over it, and a clean bevel it necessary to ensure a good sound. File it true, and remove any bur on the inside of the pipe.

4. In order to direct a blast of air right at the wedge, the inside of the pipe leading up to the notch needs to be partially blocked with some dowel. This is done by filing one side of your 1/2″ dowel flat – take off about 1/16″ or so. You will need to do this to 2″ of the dowel, then cut it into 1/2″ lengths.

5. Press the dowel-plugs into the mouth end of copper pipes, carefully aligning the flat void with the angle of the wedge cut-out. Plug the far end of the pipe you are working on with a finger and blow in the mouth end. CHOO-CHOO! You are getting somewhere. Once you have assured yourself that the sound is working, glue the plugs in.

6. Turn a set of end plugs on a lathe, or cut 3/8″ of your 1/2″ dowel to plug the far end of each pipe.

Make a toy train whistle for your train lover: a fun DIY toy project that will delight kids!

7. Make a 4″ long mouth-piece that will join the pipes together.  Start by laying out an X running from corner to corner on the end of a 2″ x 2″ piece of close-grained hardwood. Mark 1/2″ from the centre in each direction – this will mark the 5/8″ holes you will drill to mount the pipes in.

8. Drill the 5/8″ holes 3/4″ deep. These holes are close together, so you want them straight – I used a drill press and a Forstner-type drill bit. A spade or twist bit would work too, but you might want to space your holes a bit further apart if you use one. Drill a 1/4″ hole right through the centre of the block, from one end to the other.

9. Drill 1/4 holes to join the 5/8 holes with the hole running down the centre. This will distribute your breath to the four chambers.

10. Turn the mouthpiece on a lathe, or cut and file it to a taper. The hole that runs through the piece makes it handy for mounting up true on a lathe. Once the mouthpiece is finished, plug the central hole where it comes out at the far end. Now the force of your breath will only pass through the pipe chambers.

11. Glue the pipes into the 5/8″ holes, to the depth of the notches. Align the pipes so that the notches radiate outward. Give it a toot to make sure everything is working before the glue sets. Done!

You can leave the wood unfinished or treat it with any food-safe oil or wax. I used regular vegetable oil on Budster’s, because it has worked well on his other wooden toys, and is easy to touch up. The copper will oxidize quickly after being polished, and can be waxed or varnished to keep it shiny. Alternatively, untreated copper will tarnish to an even dull brown, like an old penny. However, if the copper starts turning green, be sure to clean it, because the “verdigris” isn’t safe to ingest.

Make a toy train whistle for your train lover: a fun DIY toy project that will delight kids!


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Budster loves his whistle, even though he will have to be a couple of years older to have the lung capacity to blow it. Actually, he loved it before it was even finished. While I was still tuning the pipes in our basement workshop, I could hear squeals of delight and exclamations of “train!” from upstairs at every test blow. Here is how it sounds, now that it is finished:

A possibility that I have considered is making a single-pipe whistle in the same vein, so that it will be easier to blow. If anyone tries it, please let us know in the comments!

Well, I had better make tracks. Train tracks, that is!

If you liked this craft, you may also find these related activities interesting:

Wooden Road Tracks and Ramps

How to Make a Toy Wooden Paddle Boat

– How to Make a Puppet Theatre

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Make a train whistle for your train lover: a fun DIY toy project that will delight kids!