These parameters are for adjusting the pitch, timbre, material thickness, and other properties of the pipe you want to build. Each setting is discussed in detail here.
The pitch of the pipe, specified as a MIDI note number, where 60 is Middle C (261.6 Hz), and incrementing by one always raises the pitch by one semitone.
False indicates the end of the pipe will be open to the environment, true means it will be closed, or stopped. This affects the length of the pipe, and it more subtly affects the width, mouth height, and windsheet thickness.
The thickness of the plywood you are going to use for the top part (resonator) or the pipe. This also determines the wall thickness of the 3d printed part.
The thickness of the felt you are going to use to line the inside of the plywood tuning slide.
The length of the stem that lets air into the bottom of the pipe. This does not affect the sound of the pipe.
The outer diameter of the stem that lets air into the bottom of the pipe. If you make it really small this web page will adjust it so the inner diameter is 1 mm. Air flow goes with the diameter to the 4th power, so just make it big enough to not restrict air flow
The pipe will be shortened by this many half-steps so that it can be tuned down to the correct value by lengthening. Normally a stopped pipe would be tuned up by shortening the pipe, but because of the restrictions of laser-cutting, here we take the approach of making all pipes too short, and tuning them by attaching an open or closed slide to the outside of the pipe. If you need your pipe to be too long so it can be stopped with the traditional method, you can enter a negative number here.
Width of the kerf of the laser (or router) used to cut the plywood.
This makes the pipe wider or narrower than it 'should' be. Positive values make the pipe narrower, negative wider. Should range from about -10 to 10, with negative numbers having a more string-like sound, and positive having a more flute-like sound, and values near 0 are for principals. +4 means this pipe will be as wide as a pipe 4 semitones higher should be. This page uses a 17th halving ratio. more info.
This number, together with the air pressure, determines the wind-sheet thickenss of the pipe. 2 will give the pipe maximum efficiency and bring out the fundamental tone. Increasing it will bring out the higher harmonics, and above 3 the pipe will be overblown. more info.
The air pressure, above atmospheric pressure, of the pipe's air supply. Used in determining the windsheet thickness. Typical air pressure should be 50 to 75 mm (2 to 3 inches) of water. This refers to the static pressure as measured with a U-tube manometer. (See Ising's Number, above.)
These values are computed based on the settings you endeted in the Settings panel. Each valus is discussed here.
The frequency of the pipe in cycles per second.
The inner width and depth of the pipe. Calculated using this.
The height of the opening at the front of the pipe. This is related to the frequency of the pipe, and whether it is open or closed. More info.
The width of the thin slit where air exits the pipe. This has to do with the Ising number and the air pressure of the organ's air supply, which you can adjust. Make sure your 3d-printer has a high enough resolution to make this gap accurately. More info.
The total volume of air that will flow through this pipe in one second, given the supply pressure and the windsheet width. More info.
The outer diameter of the air inlet stem at the bottom of the pipe. You can change this in the settings, but if you make it too small the software will adjust it, so the number here will reflect the actual dimension.
The total theoretical length of the functional part of the pipe, from where the air exits the mouth of the pipe, to the top of the pipe (for a closed pipe, the top of the inside of the pipe), calculated using this. The actual pipe will be somewhat shorter because of the Tuning Headroom, and the tuning slide will bring it to final length.
The length of the plywood resonator part of the pipe. That is the total Pipe Length (as above), minus the functional part of the pipe length that is 3d-printed, minus the tuning headroom. It is the length of the longest pieces of plywood to be cut.
The tuning headroom, in millimeters. You can adjust it in semitones in the "Settings" panel. This is approximately how much length you will, in theory, have to add to the pipe to tune it down to the correct pitch.
You need to download the .stl file and prepare it for printing using your 3d printer's software, e.g. Ultimaker Cura or Stratasys Insight. Then you can print it. Here is an image of a finished part:
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.
In general I had a lot of difficulty getting the support material to print properly and I had to constantly watch the machine and fix it if it got stuck. Very few of the pipes I made came out with the support material looking as good as in the above photo. However, as long as the part was well supported in two critical places, the print turned out perfect. The first critical place is the overhang where the wooden top part of the pipe seats into the plastic part. The second is the mouth of the pipe where the air comes out; if this is even a little wonky due to improper support, the pipe will sound excessively breathy.
You are suppoed to download the .svg file and then laser-cut it. The finger-jointed parts should be cut out of plywood and will form the main part of the pipe and the tuning slide. The tuning slide will have a lid if the pipe is closed. The one plain rectangle in the file should be cut out of felt and will line the inside of the tuning slide, keeping it sealed and providing the right amount of friction for tuning. Here is a photo of the cut plywood:
Here is another photo showing all of the parts, including the felt.
You might need to re-arragne the parts depending on the size of your pipe and laser cutter. The parts in the .svg file are filled and not stroked, so you will probably have to turn off fill and turn on stroke with the line-width required by your printer and software, e.g. 0px or 'hairline'. I used 100% power, 20% speed, and 500Hz on 3.75mm plywood, and 13% power, 100% speed, and 500Hz for 1mm felt.
What Is This?
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
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:
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.
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.