Build Your Own Glockenspiel 

Materials

 

-8 feet of ½ inch nominal copper pipe

-4 feet of approximately ¾ inches x 2 inches rosewood.

-18 nails, 1.5 inches long and 1/16 inches in thickness

-Professional wood glue

-18 rubber bands approximately 6 inches in circumference

- Miter saw (for cutting wood)

- Pipe cutter (for cutting copper pipe)

- Fourier and ProTuner applications

-Construction ruler

-Calculator

-Filer (for sanding uneven copper pipe ends)

-Paint (two different types of paint stains: brown and black)

-4 straws of 0.28 inches in diameter and 6.25 inches in length (although length is not important)

-Hammer

-Eye protection and face mask

-74 cm of bamboo wood 0.6cm in diameter for the body of the mallet and 7 cm of bamboo wood 1.7 cm in diameter for head of the mallet

 

*Of the materials listed above, all were obtained from home (either recyclable or from the toolbox).

 

Procedure:

1. Cut a test pipe section and measure its length.

2. Use the Fourier app to measure the frequency. Keep in mind that the longer the pipe, the lower the main frequency.

3. Choose the desired notes for the glockenspiel and copy their frequencies from this table.  We used C6, D6, E6, F6, G6, A6, B6, C7, D7, which formed a C-major scale octave, plus an extra high D.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4. Using pipe cutters, cut a piece of the copper pipe and measure the length L of the test pipe to a millimeter precision by eye.

5. After the cut, let the pipe cool off to room temperature.  Otherwise its frequency will be off a little.

6. Now measure the frequency of the pipe.  Suspend the pipe on rubber bands about 1/4 of the way (22.4%) in from each end, where the nodes will be, and otherwise let the pipe vibrate freely.

7. Start the Fourier application, which will measure the peak frequency of the sound, and suspend the pipe close to the device.

8. Have a person hold the test pipe in two rubber bands about 22% of the way in from each end and tap the suspended pipe in the middle with something wooden, like a piece of dowel or a pencil. It should give a lovely bell-like tone.

9. Write the frequency shown on the Fourier app. Several frequencies will be shown, but choose the one that looks reasonable and is shown for the longest amount of time.

10. Now that the frequency and length have been calculated, solve for A. Using the formula is:  f=A/L^2 where f is the frequency, L is the length and A is a number that could in principle be calculated from the thickness of the pipe walls, the diameter of the pipes and the speed of sound in the material; calculate the value of A. In this case use millimetres for the unit of measurement.  For instance, our length was 223 mm, and we measured a frequency of 1359Hz, so our value of A was: (1359Hz)(223mm) = 67,581,711mm^2/s.  A Hertz is in units of cycles/second, so if the lengths is in millimeters, A will be in mm^2/s.

12. Now that the value of A has been calculated go back to the table of frequencies from Step 4, and calculate a length for each frequency using the principle that L is the square root of A/f.  Record all lengths up to a tenth of a millimeter.

13. Using the pipe cutters cut nine pieces of copper pipes each with the exact length (to the nearest millimetre) as calculated in the previous Step. Because copper is toxic, make sure to use eye protection and a breathing mask.

14. After cutting all the notes, use a filer to lightly remove all the jagged edges by gently sanding them.

15. After cutting each note, use the Fourier app to test the frequency and make sure it closely matches the template value from the chart in Step 4.

16. Now that all nine notes have been cut and tuned precisely, take a piece of wood and mark two pieces so that they each measure 16.5 inches in length, 2 inches in width and ¾ inches in height. These two pieces of wood will be the main body of the glockenspiel.

17. Put 19 evenly tick marks along the center line of each board, spaced around evenly (in our case it was every 2.34cm), starting an equal distance from each end (and not too close so that a nail there won't split the board), with the odd numbered tick marks being differently marked from the even numbered ones.  The odd-numbered tick marks (starting with the first tick mark) will represent where the nails go and the even numbered tick marks will indicate where the pipes should lie.

18. After precisely marking the positions for the nails and copper pipes, measure and record the inner distances between the two ends of the frame so that the main pieces form a trapezoidal configuration. This will indicate the length of the cross pieces which in our case, was 160mm for the longer piece and 116mm for the shorter one, both with the same height and width as the main boards.  Cut the cross-pieces precisely using preferably a miter saw.

19. Now that the two main boards of wood and two cross-pieces have been cut turn the main boards upside-down, with the tick marks facing down, and space them according to the measurements.  You now need to attach the cross-pieces, while keeping the long pieces the right distance apart. Making sure the two main pieces are aligned symmetrically, put wood glue on both ends of the cross pieces that will come into contact with the main boards and attach them firmly to the main pieces. As the glue dries, if needed adjust the angle of the frame for symmetry and for the correct spacing on both ends so that the cross pieces are exactly aligned with the surface of the main pieces. Wait about 25 minutes for the glue to dry and proceed onto the next step.

20. Once the glue is set, set up the frame right-side up, with the tick marks on top and the cross-pieces on the bottom.  Now arrange the pipes on the boards in their places (on each even-numbered tick mark).

21. After arranging the pipes on the two boards, cut 18 pieces of equally sized straw (about 2cm in length) so that it completely covers the nail once it has been nailed 1.2cm into the wooden. These pieces of straw will act as rubber stoppers preventing the rubber bands from sliding down the nails. Cover all the nails with the equally sized pieces of straw and use a hammer to hammer all 18 nails in their place making sure they are all nailed approximately 1.2 cm into the wood. Make sure to adjust the nails so that they all point upwards at a 90 degree angle.

22. For aesthetic purposes, paint the cross and long boards with paint.

23. Now, string rubber bands between neighboring nails in an alternating pattern. Every other rubber band should be positioned higher than the previous one. Because of the size of bands used (6 inches in circumference), first double up each rubber band and then attach it, to minimize sliding.  Then insert the pipe into the rubber band, shifting it so that the node mark on the tube is as close as possible to the rubber band.

24. Now that the glockenspiel has been built, take a bamboo branch approximately 0.6 cm in diameter and cut two pieces, each 37 cm in length. These replicates of a dowel will be the body of the mallet. For the head of the mallet, cut two 3.5 cm in length pieces of a thicker bamboo (1.7 cm in diameter) and drill a hole in each so that the thinner pieces of wood could fit in. In our case, the thin dowels did not fit precisely into the heads of the mallet, so we used wood glue to make sure the body and head of the mallet stick together.

25. After completing the copper glockenspiel, use the ProTuner app to test the accuracy of the notes and see if any changes have to be done accordingly.