In this article, we will explain how to make a diameter gauge for measuring reeds of double reed instruments such as the oboe, English horn, historical oboes, bassoons, contrabassoons, baroque bassoons, dulzains, and pipes.
Gauge components
The gauge consists of two parts:
1. Analog micrometer
2. Angular base to support the reed
Analog micrometer
First, we need to define the range of diameters we want to measure. For the oboe, for example, the range is from 9.50ø to 12.50ø.
Most analog micrometers mark 1 mm per turn on their central rod, equivalent to 360º. If we use the entire circumference for numbering, the first and last number will coincide, overlapping the first and last number. To avoid this, it is advisable to leave 10% of the circumference blank, without numbering. This is equivalent to 36º.
So, we have 324º (360º – 36º) available for numbering. If we want to measure from 9.50ø to 12.50ø, we must distribute these 324º across the 3.00ø range. This means that each 1.00ø corresponds to 108º of the circumference, and each 0.25ø corresponds to 27º.
We can now create a new scale of values on the micrometer dial, with a precision of 0.05ø per line. This will allow us to accurately measure the desired diameters.
With this data, we would have the analog micrometer part ready. Now let’s move on to the other part of the gauge: the base where the reed will rest for measurement.
Base to support the reed
To design the base where the reed will rest, let’s again consider that we want to measure diameters from 9.50ø to 12.50ø. The circumference of the micrometer has a 10% margin, leaving us with 0.9 mm per turn to measure the diameters (1 mm – 10%).
The opening angle of this base is crucial. To calculate it:
1. Use a graphic program to overlay two circumferences on the same vertical line.
2. The bottom parts of these circumferences should be 0.9 mm apart (0.1 mm = 10% blank).
3. Draw common tangents on each side, touching only one point of each circumference.
4. The angle formed by these tangents will be suitable for our gauge.
With these steps, we will have designed an accurate base to support the reed and measure its diameter precisely.
Gauge manufacturing
With all this information, we can proceed to manufacture our custom diameter gauge. This device will allow us to accurately measure the reeds of our double reed instruments, ensuring optimal quality in our measurements.
About us
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