Hot Pans - Stockholm Steelband
© Ulf Kronman, The Pan Page. Publisher: Musikmuseet, Stockholm, Sweden.

A. Measures for common steel pan models

This appendix describes some commonly used steel pan models, together with data on note sizes, sinking depths, side lengths, etc. The measures have been gathered from instruments built in Sweden by the tuners Rudy Smith and Lawrence Mayers and during a research trip to Trinidad in March 1990. Some measures for the lower pans are still missing. As different tuners use different measures, the measures given here are to be seen as guideline examples.

Definition of measures

This section contains a description of how to apply the measures in appendix A. Please note that the length of the outer notes, denoted "along the rim", is measured using a flexed ruler held against the rim. It is easier and more precise to follow the rim than to use a straight ruler when checking the length of the outer notes. The sum of the note measures along the rim should equal the circumference. The inner diameter of a regular drum is 567 mm, which means that the circumference is 567 * pi = 1780 mm (pi = 3.14). A good way to make sure that the measures are correct is to take a measuring-tape, mark the lengths of the outer notes clockwise, and then paste it to the inside of the rim before marking the notes.

Photo

Fig. A.1 Definition of measures.

The lengths of the radial grooves (the ones going from the rim towards the centre) are measured all the way up to the rim, even if the groove stops about 40-50 mm from the rim. This is because the whole length is a more exact measure.

The outer notes that have a rounded inner border will extend a bit beyond the length of the groove. The length from the rim to the inner groove is given by the radial length of the outer note, see fig. A.1.

The tangential lengths of the outer notes are given for comparison purposes and possible future theoretical calculations of note sizes only. These are not suitable to be used for pan making.

Conversion table - mm to inches

All measures in this handbook are given in millimetres (mm). I have chosen this unit because it is metric and well accepted in technical and scientific literature. As the tradition of steel pan making is based on inches, a conversion table and a conversion diagram is provided here. An inch equals 25.4 mm.

Inches

Millimetres

Centimetres

Meters

0.04

1

0.1

0.001

0.4

10

1

0.01

1

25.4

2.54

0.0254

39

1000

100

1

Photo

Fig. A.2 Conversion diagram between millimetres and inches.

Note sizes

To get an overview of how the note size is related to the pitch of the note, I have compiled note-size data from all measured pans (except the nine bass) into one diagram.

Photo

Fig. A.3 Diagram relating note size to pitch.

Templates for sinking

The shape of the overall sink is of vital importance for the later backing and tuning. The main idea is to make the surface between the notes concave spherical in shape. But, in order to make the notes in the outer circle raise properly during the later backing, there must be a deviation from the concave shape near the rim. The surface should be straight or slightly convex here, resembling the final shape of the outer notes.

When the pan is backed, the surface between the outer notes should be lowered down to form a uniform spherical shape. Since the outer notes of the lower tuned pans are bigger and higher, the height of the convex part near the rim has to be higher in a degree corresponding to the height of the final note dents.

The template graphs given in fig. A.4 and A.5 have a special design. The pattern for each pan involves two shapes: one for the shape of the surface between the notes of the finished pan and one showing the shape measured through the highest note. The shape to be used during the sinking phase is the higher one, because at this stage material should be left to form the notes later. This template is the most important one.

The second shape is given to show what the overall shape should be after backing, grooving and levelling. This template can be used after the backing to check that the surface between the notes has an even, spherical shape.

The best way to make sinking templates out of the patterns below is to copy the page twice for each pattern. Then take one of the copies and turn it back to front, to form a left and right side of the template. Paste the left and right shapes together, carefully adjusting them to match the correct depth of the basin for the intended pan. The next thing is to paste the template to some stiff material that can serve as a guiding template during the sinking.

The straight lines at the top of the patterns should not be included in the template, they are there just to serve as a reference to the vertical outer side of the drum. These lines should be vertical when you paste the left and right parts together. Last, cut the template after the shape lines.

Photo

Fig. A.4 Sinking templates for tenor, double second, cello and six bass. Full scale right side. Cross-section of the surface along the groove and through the most convex note for each pan. Drawing by Johan Larsson. Click on one of the figures to watch the sinking templates in "full scale".

Photo

Fig. A.5 Sinking templates for double tenor, guitar and tenor bass. Full scale right side. Cross-section of the surface along the groove and through the most convex note for each pan. Drawing by Johan Larsson. Click on one of the figures to watch the sinking templates in "full scale".