Free download - Scaling graph for Organ Pipe Voicing

As I’ve been working to bring Topfer PipeCAD up to snuff I’ve gotten a tremendous amount of useful feedback from George Bozeman. One of his many suggestions was to implement the capability to produce logarithmic graph paper which could be used in conjunction with the voicer’s proportional dividers to transfer measurements directly from a graph to a pipe. Additionally, having the capability to print out blanks of the graph template would allow it to be used for manual “pen & ink” scaling. Given the size constraints of the graph, it’s most useful for voicing measurements, but being based on the logarithmic Normalmensur progression it can be applied to other scaling tasks as well. Although I’m sure it will seem obvious to many of you, gentle readers, it was something that I hadn’t thought of as I worked on PipeCAD, but which I immediately saw as a tremendously useful idea.

Thus, I’ve been folding that idea into PipeCAD as well, and will include the option to generate various graphs for use with proportional dividers when PipeCAD is printing reports. As a bonus, I’m including a free downloadable template file so that you can print your own graphs. Click on the thumbnail of the graph to the right to download a copy:
If you’re unfamiliar with the use of a Scaling Graph like this one, then let’s take a look at a very simple example. We will enter the known cut-up measurements of several pipes which have been voiced to our satisfaction, then use the graph to find the measurements of the cut ups for those pipes which lie in between our known values.

Start by entering any project information that you like in the area reserved for your own notes, as shown above. Also label the vertical axis on the left for the graph line you are about to enter.

Set your proportional dividers such that the largest and the smallest measurement that you anticipate can be comfortably contained with the graph (that is, the measurements are not too small nor too big to be transferred accurately without difficulty). Begin by entering your first data point, as illustrated above. Remember, all measurements are made from the graph baseline up to the point of intersection of the note axis. Take care not to change the setting on your proportional divider as you proceed with transferring the measurements from the pipes to the graph.

Continue transferring the measurements from each voiced pipe until you’re done. In the case of this example we’re entered a number of measurements taken at various C’s. Remember, always measure up from the graph baseline, and take care not to change the setting of your proportional divider as you proceed.

After all points have been entered you can connect them with straight lines. These lines cross the note axes at a proportional height for each note.

Using your proportional divider again, you can now transfer the measurements from the note axes to the pipes needing voicing. Done!

Note: The Normalmensur (halve on the 17th) is always represented by any line parallel to the baseline. The log scale of this graph is computed using the Normalmensur.

Note: I haven’t heard back from anyone who has used this template since it has been posted. If you spot any errors, please send me a comment! Thanks!

Many, many thanks to George Bozeman for providing this idea. I hope that this template will be of great use to many organ builders!

Have fun!

MirthMaker