(a blast from the past)

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      The first time i saw one of these little whistles was in a craft shop in Vermont. I was delighted with the sound it made and it looked like something i could make for myself one day. I noticed how it was built, and taking a straw from a broom, i used it to measure the depth of the holes for future reference. The deepest one was from heel of my left hand to the tip of my index finger, which measured out later on to around 7 inches. The shallowest one only measured across the palm of my left hand, or about 4 inches deep. I just figured the other two were in between those two figures and called them 5 inches and 6 inches deep.  So just by looking at the whistle in the shop, i was able to determine exactly how to build one, complete with dimensions.   
      The other day i was sitting around and got the urge to make something. I thought of the train whistle and decided that enough time had gone by and i had picked up enough knowledge making other types of flutes and whistles to give this a try.  I started out with a 9 inch long piece of 2x4 lumber. Nothing special at all, however a hardwood would be easier to build it from due to the smaller difference in density between the rings and the in between softer sections.   Using plain fir or pine, the grain dividers are much harder than the spaces between the lines so it is not all that easy to drill a good straight hole 7" deep without wandering a bit and my first try resulted in the grain leading my drill right out the side of the whistle, ruining the first attempt and forcing me to start over from the beginning. Luckily, the first operation was to split that piece of 2x4 in two halves, which measured roughly 1½ " square and 9" long.  I had better results with the second attempt and here is what i did to make the whistle you see below.

( click photo to hear the sound this whistle makes )

(musical instruments page)



Steps in Construction of the Whistle




Selecting and preparing the stock

     If you can find a good quality close grained piece of 2x4 that is at least 9 inches long, you have the start of your whistle.   You can use anything just about and the whistle i made, and you can hear by clicking on the photo at top, is made from a plain piece of fir stock.   Usually lumber from objects such as shipping pallets are made with harder wood and they may be a good source of stock for your whistle.   Be sure the grain if as closely parallel to the sides of the material as possible. If the grain runs at an angle then it may deflect your drill when you make your holes and cause you to have a difficult time with the spacing between the holes or could actually break through one of the outside surfaces if the harder grain portion of the wood leads your drill off at an angle.   If you prefer you can even go buy a piece of 2x2 material of different type wood, such as Poplar, which is a good easy working type of wood that will give excellent results.
    Once you have selected your stock, cut a piece that is 1½ square (minimum) and 9 inches long.   Measure off  7 7/8"  from the bottom and cut off a piece from your material that measures 1½" square and 1 1/8" long. The one i ended up with was actually 1/16" heavy on the 1½" dimension. This piece will later on become your mouth piece for the whistle but set it aside for now.    You are now ready to begin the construction of your whistle. You should have two pieces of wood now, one that is 1½" square and 8" long, and one that is 1½" square and 1 1/8" long.  Sand the area where the saw cut through and make it smooth and flat because these two pieces will be joined later on and the surfaces will need to be flat and smooth to make a good air tight seal.

    You should have two pieces of wood now, one that is 1½" square and 8" long, and one that is 1½" square and
1 1/8" long.   Sand the area where the saw cut through and make it smooth and flat because these two pieces will be joined later on and the surfaces will need to be flat and smooth to make a good air tight seal.   You can see that instead of 1½" square, my material was a sixteenth of an inch thicker. All this does is give you a better chance of avoiding hole collisions when drilling because the wall thickness is slightly greater and you get an extra 1/32 of an inch to wander off target with the long holes.  All the dimensions given from here on are calculated from the size stock shown at left.   If you use smaller stock, then the dimensions will have to be altered accordingly.




Laying out the holes

     In order to get that discordant blend of sounds that the old fashioned steam engines had, the holes must all be different lengths.   I went (roughly) by the measurements i took off the whistle in the souvenir shop.    Here you can see how deep to drill the holes.  It doesn't matter how you number them as long as they have different numbers and different depths. Their proximity to each other does not matter at all nor how they are arranged, as far as the sound goes it is all the same.   The layout is easy, but the drilling is tricky.

    The goal here is to leave yourself the maximum space between the edge of the holes and the outside surface of the whistle while maintaining the widest distance between the holes themselves.
     Using the size stock i had on hand, these are the dimensions that i am trying to achieve, where i have the 3/16" edge distance in all cases, so i have maximum room to wander when drilling.   Having determined where i want the 1/2" diameter holes to go, i then converted these reference figures into hard dimensions for my layout as shown below.




Drilling straight holes

     This is the tough part of the project.  We have to drill four holes that are only allowed to wander from true straight line by less than 1/8 of an inch over a possible seven inch distance.   In order to do this, it is vital that your pilot (starting) holes are as straight and parallel as possible for the greatest distance possible.   Unless you have a marvelous work shop filled with equipment you will be finishing up the drilling operation by hand with a portable drill, so the guide holes must be very good in order to keep your finish size drill on track and straight.   I used a 1/8 diameter drill in a drill press, held square by clamping to an angle iron.  Although the pilot holes were only about 1½" deep, they were sufficient to keep my lead drill on target.  Making these initial holes as close as possible i spotted the locations with a punch, as shown below left.  This particular punch is spring loaded and needs no hammer to make it work, just push on it.
   It is important that the holes are parallel to the sides and straight so i had to set up a good method of holding the stock square to all planes.  I did this by clamping it to a precision angle iron, one of the tools i made while i was a tool and die maker and works just as well for wood as it did for metal parts.   Below left you can see how i set the stock on the angle and aligned it vertically with a simple square.  Clamping it in this position makes the stock perfectly vertical and parallel to the axis of the drill press, where the pilot holes will be drilled.      You can see in the photo at lower right how the stock is clamped to the angle iron for drilling of the pilot holes.  It was so high that i had to swing away my drill press work table, and work directly off of the base surface.

     A jobber's drill bit does not have any clearance along the margins, nor does it have any cutting edges other than the very tip, so it is designed to follow existing holes more accurately without wandering off in one direction or the other as is the case with standard sharpening with clearances and cutting edges on the margins.  

  The goal is to make the pilot holes that are drilled on the drill press, as deep as you can, the length of the drill if possible. The longer the hole, the less chance of wandering with the guide drill that follows.     The guide drill is the same diameter as the pilot drill (1/8") except it is a "jobbers" drill. This means that it is perfectly cylindrical with no back clearance on the drill flutes.  It is designed to only cut on the leading edge of the drill and not on the sides, which are only used as guides and follow the point, where ever it goes.  So you can see that the longer you make the pilot holes, the better chance of getting that drill point pointing in the right direction.   Once the guide drill is going straight, it does not take much to keep it straight except to withdraw it frequently to let the chips out so that they will not build up and overheat the drill or cause the drill to wander.  If chips build up and can't find exit, they gouge the sides of the hole and make it easy for the point to wander so it is vital to only drill till the flutes are full, then withdraw the drill and continue again.
   With the pilot holes in the block, we can now use the jobber's bit to bring each hole to it's proper depth.  To do this, i simply measured off the depth i want the hole to be and placed a little piece of masking tape on the drill to mark that place.   You can see by the photo at left that there are a few pieces of tape on the drill bit.  As each depth is reached, the tape marking that distance is removed and the next hole is drilled.  Remember that you must clear the drill often by withdrawing it as soon as the flutes are filled with wood chips from the drilling.  Failure to do this often enough could result in your hole veering off to one side or the other.  Normally even slight errors in the angle with which you hold the drill are ignored by the jobber bit, as it attempts to follow faithfully the original pilot hole direction.
     The bit shown at left is a spade bit.   It is called that because of the flat shape it has, and this bit is only good for soft materials such as wood.  You can see that it has a formidable tip which guides it through the wood and keeps the drill from wobbling and producing a hole that is not perfectly round.   This long leading tip of the spade drill will tend to follow the path of the guide holes that you just installed at the proper depths of 4½", 5½", 6½", & 7½".  When you open the guide hole with this bit, try to keep the shank of the drill, which is smaller than the cutting end, centered inside the larger bored hole.   Even though you have a guide hole, it is possible to walk off location with this bit, or "steer" the hole slightly.   It is important that it follow the guide hole faithfully.

The pieces of tape that mark the depths on the spade bit do not have to be removed as they are used due to the smaller diameter of the shank with regard to the hole size.  They do not touch the hole as they enter it so they can be left on the drill for future depth reference.
     Here is the long spade bit in action.  The initial starting is critical as this is the guide for the rest of the drilling of the hole.  Keeping the shank of the spade drill centered in the hole can't be done until the hole is deep enough to cover the entire wide drilling section, so you have an inch or two of drilling that must be done with precision.  I used a small level to level up the piece in the vise, in the photo at left.  Once the stock was level with the earth, i knew all i had to do was keep my portable drill level and i had the best chance of a straight hole.  Luckily my portable drill has a build in level so you can do just that.   If you do not have this feature, you may wish to employ a friend to help you view the angles from a different view point and advise you to lift or drop your drill motor while making the hole parallel with the stock.   You can align it in the other direction by eyeball while your friend advises about the up and down angle of your drill.



Making the Bevel edge


     The next step will make the sound producing portion of the whistle. Let's just call it the bevel, because that is what it is.  This will shape the sound of your whistle.  A larger bevel will produce a more "airy" louder whistle, while smaller areas for the bevel will produce softer quieter tones.  Lay out your bevel as shown in the illustration at left, if your stock is the same size as what i used, one and nine sixteenths inches.  If different, then only alter the 21/32" figure and keep the 9/32" figure as a constant, centered on each face always 9/32" regardless of what the distance to the edge happens to be.  It is very important when actually making the saw cuts that you stay away from over-cutting into this 9/32" area.  If you do, then you may have trouble making that hole sound properly or even sound at all.  Saw up to the lines but do not go over them. You can do the finishing up work with a file to make sure the corners are sharp and even and the faces of the bevels are smooth and flat.   The bevels MUST NOT be installed before the holes are finished or you will run into big problems when you try to drill the holes and the drill breaks through the bevels.  The bevels must be installed AFTER the holes are completed.

     The stock is rotated 45º in order to cut the bevels.  If you do not have power tools, do this in a vise and go very slowly with a fine pitch saw blade, watching both sides of the layout to avoid over-cutting the lines.
     Because the saw cuts will be at a 45º angle the whistle must be tipped at that angle in order to saw out the notches that form the bevel.  Again, my old tools from another trade came in handy.  At left you can see the block of stock resting in a precision "Vee" block.  You do not need anything as fancy, and you can make a vee block from wood, very easily that will work just fine for this step.  The important thing is to tip the stock at 45º before attempting to make the saw cuts.   Do not cut over the lines, leave them for witness lines that you can go by when finishing up the operation with the file.  You will need a file with an angle shallow enough to get into the beveled surfaces without gouging them.  I used a three cornered, triangular file for this step and it worked out just great.  When you are done, the surfaces should be smooth and flat and the edges of the bevel clean and free from splinters, burrs and other non-uniform obstructions to air flow.   A light touch with very smooth sand paper can do this.



Forming the air channels


   The dowels block the top of the holes except for where the air passes through, over the flattened area.  This makes an air channel that is directed at the edge of the bevel and produces the tone for that hole.
     Now with the bevels done, we can make the air stream that is directed at those bevels to make the sounds.  I used standard ½" dia. wooden dowels, available at many hardware stores.  Should they be too loose in the holes you can make them larger by wrapping them with a layer of news paper that has been wet with a solution of one part white glue and one part water.  Wrap the paper around the dowel until it fits smoothly in the hole, then cut the paper length at that point.  Dip the paper into the glue/water mixture and then wrap the dowel again and set it aside to dry.  In an hour or two you will have a custom dowel that fits nicely in the hole.  Sanding of the hole could have been the cause of a loose dowel, or just bad quality control at the dowel factory, but what ever the case, this works fine.
     Sand or file a flat on the dowel as shown in the figure at left.  I recommend you keep the dowel in one piece, allowing 1/16 for each saw cut, and make the flat on all of them at the same time while they are all in one easy to handle piece.  Cut them to length after the flat is installed on the dowel face.  You need 4 of these dowels for each whistle.   The flat place provides an air channel for the whistle that strikes the edge of the bevel and causes the air column in the hole to vibrate at a rate that is proportional to the depth of the hole.

     Above left you can see what the dowels look like when inserted into the holes at the top of the whistle.  They should be pushed into the holes until their leading edge is flush (even) with the edge at the end of the 7/8" top portion of the whistle. They must be aligned at the same 45º angle that the bevels assume.  It is very important that the flats on the dowels are parallel with the surface of the bevel.  This is the air channel that makes the sound and if it is not situated correctly, then there will be a severely compromised sound from the whistle, if any sound at all comes from it.   After the whistle is complete, you can still adjust the sound with a file, touching up the bevel by hand.   Insert the dowels into the holes so that they are at the 45º angle and flush with the top surface of the bevel, the bottom face of the top 7/8" area. Be sure that the end of the dowel is smooth, flat and the edges are clean.  Any splintering or jagged edges can alter the sound by obstructing the air flow.  Glue the dowels in place once you have them located properly. Allow the glue to dry for several hours before you to on to the next step.  Once you have attached the mouth piece you will not have access to these dowels again. You want to make sure that they all make a sound before you put on the mouth piece.  Test them individually for tone, and make any adjustments you need by working the bevel with a file to increase the sound, or sanding the air channel to make it carry more air. There are a few things you can do here to alter the sound. Remember that all of the edges must be "clean", which means free from any roughness, or other things that could cause the air stream to deflect or diminish.



Making the mouth piece


  Cut-away view of the mouth piece after the spot face and the holes have been drilled. The spot-face overlaps all of the holes in the whistle when it is assembled. When the air stream comes down the 5/16" channel, it is directed into all four holes by the spot-face chamber which is open to them all.
    It is time to retrieve the piece we cut off of our stock in the beginning.  This will be come our mouth piece.  Remember you sanded the bottom surface flat and smooth, so turn it over so the bottom is facing up before you make your layout.  Draw a straight line from corner to corner for all the corners which will leave you with a large " X ", on the stock. The center of this " X " is the center of the mouth piece. Mark it carefully with your center punch to make a starting point for the spade drill.   This time use a 1" diameter spade drill to make the shallow spot face, 1/8 deep in the bottom.  Next take a 5/16" diameter drill and follow through to the other side with it. In the illustration the front half of the block is cut away so you can see the shape of the spot face and hole more clearly.  Do not shape this block until the final stages of the project, after it has been glued to the body of the whistle and will blend nicely when sanded along with the body in the finishing stage.   After lightly sanding the edges of the spot-face to remove any roughness, apply a light coating of glue to the end with the spot-face and place it on top of the whistle. Take care not to let any glue drip into the holes with the dowels in them.  Give the glue a minimum of 8 hours to set before going to the next step of shaping the mouth piece.


    This is the last time you will see this end of the dowel pin air chambers so make sure all of the notes work OK before assembling the mouth piece.  If a note does not work you can use a three cornered file to shape and alter the bevel over the note that does not work.  If not enough air is reaching the bevel, then a small strip of emery cloth can be threaded through the air chamber and you can enlarge it by sanding the whistle body (which is softer than the dowel) , drawing the strip of abrasive cloth back and forth through the air chamber.  Be careful not to damage the edge of the bevel while doing this.   All edges that will be closed covered when the mouth piece is assembled must be sanded and made free from roughness or debris such as saw dust or chips.  This includes the edges of the spot face, but NOT the outer edges of the mouthpiece. Leave them alone for now because they will be shaped after gluing and curing.  Just the inside edges need to be clean.
  Pass both the mouth piece bottom surface, and the whistle top surface over a sheet of fine sand paper, laid on a smooth flat surface to make them smooth and flat. When these two are assembled the junction must be air tight.    Clean both surfaces with a brush or cloth to remove any saw dust or chips that may still be in side the whistle or mouth piece and apply a light coating of glue to the bottom contact surface of the mouth piece.  Do NOT put any glue on the top of the whistle, as it may run into the holes and prevent that tube from sounding properly.  Only a light coat is needed on the bottom of the mouth piece alone.  When you nest it on top of the whistle you can feel it settle, look for a small amount of glue to be showing along the outside of the junction. This will mean that you have a good seal all around.   Let the whistle stand now and cure for at least 8 hours before going on to the shaping and finishing stage.

Shaping and Finishing


After gluing and curing, the mouth piece can be shaped to a more pleasing and functional shape. Sanding while assembled gives a more professional look to the finished item, where all surfaces blend perfectly with all other surfaces.
     At left you can see that a large chamfer has been put on the mouth piece to form a small half inch square that is easier to blow into than an inch and a half block against your mouth.  In this model, i made the sides straight like a pyramid however when i made the real one i blended the lines to form a large bullet shaped end the blended from square to round as the eye traveled from bevel to blow hole. I preferred the less rigid curve of the parabola to the pyramid starkness. Just a matter of taste, be creative and shape it any way you like. Just be careful not to encounter the corner of the spot face while you are removing material from the mouthpiece when you shape it.  If you have an air leak, the whistle will not work.
   Your whistle is finished and all you need to do now, if you choose is put a coat of wood finish on it, either oil, lacquer, enamel, acrylic, etc... what ever you prefer. If you apply a wood finish be sure not to alter the shape of the bevel with varnish nor get any in the air passages or your whistle's sound may be effected.




Making it sound better


     You can make a big difference in the sound of your whistle by using a little technique and variation when playing it.  You will find that if you start softly at first, and gradually increase the amount of air you blow through the whistle, you will hear different tones kicking in at different pressures.  Unless you were extremely lucky when constructing your whistle, not all of the notes will play with the same pressures.  So varying your breath volume will alter the sound of the whistle. You can just blow mechanically into it for a "toot, toot" sound but if you exercise a little variation in how hard you blow, changing it from soft to hard and back again while blowing you will find that you can give a little character to the sound.  You will hear when you are doing it best because it will sound more realistic to you.  Listen to the clip i made and try to make your whistle copy that sound.  (i added a little echo effect to the sound, to enhance it )  Have fun, enjoy both the whistle and the feeling of accomplishment you get when ever you make something with your own hands.

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