Rubber Band Instrument

Intro: Rubber Band Instrument

Rubber Band Instrument

My daughter needed a rubber-band-based instrument so after some brainstorming we came up with an instrument that had the rubber bands stretched inside a PVC tube. The rubber bands are stretched between brass nails hammered into 3 x 1/4" birch wood planks. The bottom wood is fixed to the bottom of the PVC pipe. The top wood is arranged to slide upward and increases the tension on the rubber bands and increases the pitch.

STEP 1: Cut PVC Pipe

Cut the PVC pipe as shown to provide a nice opening to access the interior of the PVC pipe where the rubber bands will live!

Be careful as you cut the curve so as to not bind the saw blade. I used a band saw but a coping saw should work too.

STEP 2: Fasten Blocks to Ends of Boards

The two 3 inch wide boards slide nicely inside the PVC tube.

Blocks are glued and screwed onto the end of each of them. Drill pilot holes in the block so screws can easily pass through to board.

The bottom board has a block that is just slightly smaller in width than the board so it will fit into the PVC tube.

The top board will need to slide and will have a block that is wider than the tube (extends past the edge of the tube on both sides) so that it will not slide down into the tube, but can be pulled out of the PVC tube.

STEP 3: Fasten the Bottom Board to the PVC Tube

Holes are drilled through the PVC tube sides so that screws can be screwed through the PVC tube into the bottom board block to fasten the bottom board to the PVC tube. This fixes the bottom board into place inside the bottom of the PVC tube.

STEP 4: Add Brass Nails for Rubber Bands

Brass nails are hammered into the top edge of the bottom board for attaching the rubber bands.

STEP 5: Add Staggered Brass Nails

Brass Nails are hammered into the bottom edge of the top board in a staggered fashion so that the rubber bands each have a different tension and tone. Install the rubber bands between the sets of nails on the top and bottom boards.

STEP 6: Add Accesssories

Add the strap by measuring a suitable amount of nylon webbing. The webbing was doubled over and a screw was driven through the webbing into the PVC pipe. The point of the screw inside the PVC tube was covered with hot glue to prevent injury.

A wood foot hold was attached to the bottom of the wood block on the bottom board with screws so that the PVC tube could be held to the ground if the instrument was played sitting down.

STEP 7: Play Your Instrument

The instrument can be played standing or sitting. Pluck the rubber bands....

The tone of the rubber bands can be changed by pulling up on the top board and sliding it upward to increase the tension on the rubber bands. If you are sitting you can put your foot on the foot hold and pull up on the top board. If standing you can't really pull up on the top board so a block of wood can be inserted between the top board block of wood and the top of the PVC pipe to essentially shim the top board upward in a fixed modified-tone setting.

[In hind sight we would have made the difference in tension between each of the 4 rubber bands greater (staggered more) so that there was a more noticeable difference in tone.]
Have fun playing your rubber band instrument. Enjoy!

Comments

[KetkA]

Un instrumento musical muy original. ¡Enhorabuena!. también me gustaría verlo como suena en algún vídeo. Un cordial saludo desde España.

[wannabemadsci]

No suena muy bien. En realidad no recomendaría construirlo.

[KetkA]

Oh!, lo siento mucho que el resultado no sea el esperado. Eso a veces ocurre con bastante frecuencia en el mundo de la ciencia, y crear un instrumento musical de cuerda es ámbito de ciencia.
A mí el diseño me gusta mucho, por su originalidad, un instrumento de cuerda dentro de un tubo.
No puedo saber porqué el sonido no es bueno. Te animo a hacer un vídeo corto en Youtube y darme el enlace URL al mismo para poder observarlo.
Sin verlo, se me ocurre que el material de las cuerdas (goma) no sea el adecuado. Se me ocurre que quizás le falte caja de resonancia. Lo cual se podría suplir añadiendo un amplificador que puedes comprar en kit por poco dinero.
Necesito poder verlo y escucharlo, para diagnosticar el problema.
Un cordial saludo y mucho ánimo. No des esta batalla por perdida.
Ketk Aiball. (https://www.youtube.com/user/Ketkaiball/videos)

[wannabemadsci]

[Google Translate] Mi hija lo llevó a la escuela antes de que pudiera grabarlo en video. Creo que ha desaparecido, así que no tendré la oportunidad de grabarlo en video. Creo que la falta de una caja de resonancia, así como el uso de bandas de goma fue el problema.

[KetkA]

Pues si se ha perdido en la escuela, y si no te es mucho trabajo, podrías construir una copia del instrumento perdido y hacer el vídeo. Seguramente muchos de nosotros podríamos aportarte ideas para mejorarlo. Queda en tus manos la decisión. Un cordial saludo.

[HairyHorsefeathers]

Looks like it could be fun, but, would rather have heard how it sounded by watching a video. No use building something that may not sound goodd.

[wannabemadsci]

It does not sound very good. The school project requirement was to use rubber bands and we did, but it did not sound that good. I would not necessarily recommend that someone build it unless you decided to modify it.

[Penolopy Bulnick]

Interesting idea! Do you have a video showing off how it works and sounds?

[wannabemadsci]

Unfortunately my daughter took it to school and left it there before I could get a video recording. As noted in the ‘ible we should have staggered the nails more to provide greater tone differences between rubber bands. It sounds pretty twangy and not that great right now.

[snowf7]

If you can't move the nails further apart, shorten the elastics until you get the pitch you want. I remember my mother making a very crude guitar for us when we were little out of an empty Kleenex box and elastic bands that ran over the opening in the box. We thought it was great.