Pipe Construction Continued

After experimenting with the cardboard pipes, I began to build the pipes for the actual pipe organ. As stated in the last post, PVC was deemed to be the best material to build them from.

The first thing I needed to know was how much PVC and what sizes to buy. I figured that there would be three sections of pipes: low, medium, and high registers (This was eventually simplified to just low and high sections.) The low section would be 1-inch diameter pipe, and the high would be 3/4-inch diameter.

A pipe’s tone, although mainly a product of length, has many factors in diameter and material. I used Raphi Giangiulio’s amazing length calculator (I will be referencing Raphi’s work in a lot of the future blog posts. I cannot give him enough credit for his attention to detail.) for all my internal lengths. To take into account of the PVC material and the roughness of the formula, I added around 3 inches to each measurement. To lay out the cuts on the pipe, I made a sharpie line at 1-inch, then another full line at the end of the pipe.

This was the first prototype of the mouth of the pipe. This was connected to a full length of piping, but was cut off and used to build other pipes. There are two major things that need to occur in order for a pipe to sound.

  1. The air has to be pushed into a very thin layer of air called an air-sheet
  2. This air-sheet must be ‘cut’ by the upper lip.

Sadly, this made no sound. As I had just started using the miter saw to do cuts, I couldn’t do delicate and shallow cuts necessary to make a small opening for my pipes. This prototype just let out too much air, and the air that was compressed into an air-sheet had no direction from the pipe’s sides to guide it to the upper lip.

A simple design was proving to be the best when it came to the pipe construction. I first would make a very small cut on the 1-inch marker I mapped out previously. Then, setting the miter saw to a 45 degree angle, I would cut from above the 1-inch marker down to where the first cut ended. To create the air-sheet, I cut a thin piece of slightly-undersized dowel, sand down to a flat side, and used athletics tape to make a tight fit around it. Any wholes were filled with hot glue after it was adjusted correctly.

Adjusting is a large part of pipe building. Once I have the mouth and the languid (flattened wooden dowel), more adjustment is needed until it sounds perfectly. I found that the pipe played better when the sides of the mouth were closed in with a thin sheet of wood. I assume that this helped channel more air onto the cutting edge of the upper lip.

Photo Dec 22, 1 36 05 PM
Triangles of Balsa wood were set on the corners of the mouth with hot glue.

To finish a pipe, I would then carefully adjust where the dowel was, sometimes tilting it slightly to make the air-sheet thinner. The pipe was then cut to tone, using a miter saw and an electronic tuner. The tone didn’t have to be perfect, however, as a tuning slide would be added on each pipe to allow myself to quickly make the whole organ in tune.

From Raphi Giangiulio’s organ, showing the tuning slides and tuning shades from left to right respectively.

The tuning slides ended up being a much more interesting problem then I expected. I first tried just a paper sleeve that would tightly fit on the top of the pipe, however it looked cheap and didn’t keep its place very well. PVC couplings were the next best choice.

The PVC coupling solved a lot of the problems I had with the paper: They fit extremely tight on the pipe and fit the look of the pipes themselves. Also- there is a divider in the middle of the coupling, restricting the movement of the pipe to only half of its whole length. To combat these problems, I used a grinding bit in a cordless drill to remove the dividing ridge, and then used a hand saw to cut a vertical line as seen in the second picture. The kerf of the handsaw blade gave just enough give in the coupling to allow it to have a moveable fit on the end of the pipe. The slider only works if the whole slide is whole, so I plugged the new-found cut with a thin, sanded piece of oak, as shown in the third and final picture.

This video was made around two weeks into the building process, Oct. 7th, 2016.

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