I printed it in PLA with water-soluble PVA support material. I used 0.1mm layer height and 20% infill, and otherwise used the Ultimaker default settings. I printed my pipes in the orientation shown, as it minimized the amount of support material needed. This orientation worked well. Here is another photo with the support material removed.
Here is another photo showing all of the parts, including the felt.
What Is This?
Introduction
This page makes organ pipes. You can enter some information about the pitch and timbre of the pipe you want. It creates files that you can download and use to quickly fabricate real organ pipes! The bottom 'mouth' part of the pipe will be in a .stl file that can be 3d-printed, and the top 'resonator' part of the pipe will be in a .svg file that can be laser-cut out of plywood and felt. The pipes will always have square cross section, just like most real organ pipes, and will have a tuning slide that fits over the top of the pipe for tuning. For stopped pipes, the tuning slide will have a lid, for open pipes it is open. The pipe design is based loosely on Figures CCLXX and CCLX from the 1905 treatise The Art of Organ Building by George Ashdown Audsley, the former of which is shown here for reference.
Below are instructions on how to build an organ pipe. The pipe depicted throughout the tutorial is MIDI note number 68 (A♭4, 415 Hz), and is closed at the top. It was made using the default value for all of the settings (other than the note number) on this page.
3D Printed Mouth
First you need to download the .stl file and 3d-print the mouth part of the pipe. This is what it will look like when you are done printing it.
More info is available in the 3d Print help.
Laser Cut Resonator and Tuning Slide
Then download and laser-cut the resonator part of the pipe from plywood and felt. This is what the parts will look like when you are done cutting them out.
More info is available in the Laser Cutter help
Resonator Assembly
To assemble the resonator part of the pipe, you will need the four longest plywoodwood pieces, glue, and clamps, as shown in the following image:
Use the wood-glue to glue the four longest pieces together to form the resonator. Use lots of glue, as the resonator needs to be air-tight, and gaps in the glue where air can pass through can prevent the pipe from sounding. Clamp the glued pieces together, as shown in the following image.
After the glue is dry, sand and stain or paint the resonator. This is important, because it helps seal the joints, ensuring the pipes are air-tight. I used black latex furniture paint, followed by spray varnish, as depicted in the following image:
Tuning Slide
To assemble the tuning slide you will need all of the remaining laser-cut pieces including the felt, wood glue, Super 77 spray adhesive, clamps, and the resonator that you finished painting in the last step, as shown in the following image.
For the best fit, the tuning slide should be assembled directly onto the resonator. This is somewhat tricky, and the process I used is depicted in the following composite image, and the steps are thus:
- Put glue on everything. This includes putting wood glue on all of the finger joints of the plywood, and a coating of spray adhesive on one side of the felt.
- Assemble three of the four sides of the tuning slide, by sticking them together.
- Set the felt down into the three assembled pieces, spray-adhesive-side down, so that the felt totally lines the inside of the part and the excess sticks up where the fouth side will be.
- Press the resonator, which you assembled before, down into the felt. Use the resonator to press the felt down into the corners of the tuning slide. The spary adhesive is supposed to hold the felt to the tuning slide, and not to the resonator, as the felt is supposed to slide on the resonator. So be careful not to accidentally glue them together.
- With the tuning slide still in place, glue the fourth side of the tuning slide in place. The tuning slide now forms a complete ring around the resonator.
- If the pipe is closed, glue the lid onto the tuning slide.
Firmly clamp the tuning slide.
After the tuning slide is fully assembled and the glue has dried, you can sand and stain / paint it without removing it from the pipe. I wrapped the resonator up with paper so I could paint the tuning slide without getting the resonator messy. If the sun is shining, you might as well move your desk outside.
Final Assembly
The whole resonator plus tuning slide assembly can then be epoxied into the mouth using two-part Gorilla epoxy or similar.
I mixed up some epoxy and applied it to the inside of the 3d-printed mouth, and then pressed the resonator assembly into place. It is important that the entire joint be completely air-tight, especially in the front, so make sure to use plenty of epoxy there. The finished organ pipe is shown below.
I ended up making 24 of these pipes, ranging from MIDI note number 52 (E3, 164.8 Hz) to MIDI note number 75 (E♭5, 622 Hz), and this entire rank is shown in the following image.
What do they sound like?
Below is a spectrogram of my lowest (E3, 164.8 Hz) pipe. The three most prominent peaks are the 164.8 Hz fundamental; three times the fundamental (494.4Hz) corresponding to a 12th above (B4); and six times the fundamental (989 Hz) corresponding to and octave plus a 12th above (B5). There is an additional small peak at five times the fundamental (824 Hz) correpsonding to an octave plus a 10th (G#5). There is a sense in which the pipe sounds an entire major triad -- perceptually it sounds like one note, but the spectrogram reveals that the entire triad is present.
The pipe sounds nice and is warm and resonant, although it speaks just slightly slower than it could.
Here is a spectrogram of my highest (E♭5, 622 Hz) pipe. There is a peak at each multiple of the fundamemtal, including the octave above, and the next most prominent peaks are again a 12th and an octave above the 12th.
This pipe is very nice and crisp. It speaks very fast. With my mouth I can triple-tongue and flutter-tounge it, and it responds perfectly. It behaves nicely at almost any pressure and cannot be overblown, and is only underblown with the very weakest pressure. It has a very small amount of chiff, just enough to articulate the begining of the note, and not enough to sound silly.
Here is a video where you can hear the entire rank of pipes. They sound pretty good, although some of the pipes (notably the F) were not properly supported during 3d-printing and are excessively noisy as a result of having a slightly deformed mouth. Other than that, they sound nice, like an old baroque organ, and are very gentle and warm.