32-keyless Trumpet Organ

6 Assembly

The view above shows my basic pipe layout, which was the starting point in determining the size of case required. Then everything else was designed to fit into it. The reservoir needed to occupy as much space as possible.

The trumpets would be placed inverted, with their sound projecting out from the space at the bottom of the façade. Behind them would be the vertical transfer board taking wind down to the trumpet helpers and basses below the reservoir. The drawing shows the vertical transfer board (channels to be covered with paper), fitted below the distribution board, with the floor at the bottom. The outlines between show the position of the feeder.

NOTE: The photos in this section on assembly may show items not yet described as being fitted, as some were taken during trial assembly tests.

Above left: The floor is fitted with brackets for securing the bass pipes and trumpet helpers in position. The usual method of fixing these pipes is by glue, which doesn't allow the pipes to be removed for maintenance. Pipe speech can never be predicted as the wind channels are so convoluted, so being able to remove them easily is a great advantage. The pipe wind holes have leather gaskets for a good seal. Above right: Pipes are fitted - the three bases at the edge and the nine trumpet helpers in the centre.

Above left: The floor and vertical transfer board are now fitted. The paper covering the channels has been hardened with a coat of shellac. You can just see a few of the channels on the left side where the light has caught them. Above right: The turning crank was fitted using a commercial bearing for the back of the case and a traditional lignum-vitae bearing for the other end. I had to install the keyframe drive belt at this stage as it had been specifically made for this organ in one piece. A heavy turning wheel will be used as opposed to the more usual "handle" to smooth out the motion preventing uneven turning. A sewing machine wheel will be used, fitted with a freely revolving wooden handle.

Once the reservoir was installed and the feeders connected to the crank the next job was to install the distribution board and connect the wind trunking between the two. The lower part of the integral relay is shown on the left of this picture, and the wind holes for the pipes are on the right.

I wanted the back of the relay to be a window, showing just what is inside. The window would be in the form of a sheet of polycarbonate, which would be fitted by quarter-turn latches. The fixed part of the five latches can be seen on the left of the picture.

Above left: A divider board was fitted to separate the action at the back from the pipes at the front. The opening on the right of the picture is to allow the de-tuned rank of bourdon celestes to speak, as they would be facing backwards. Above right: These are the separate pieces which make up the slider control for the melody forte register. The middle strip (slider) locates in the channel in the bottom strip, with the top strip finishing off the assembly. The slider (treated with a dry silicone release agent) is moved sideways to open or close the wind holes. It would operate through impulses in the music acting on the wire projections fitted to the slider. The white patches are paper spacers to allow the slider to move freely.

The first pipes to be fitted into the main pipe chamber were the accompaniments. The largest three are on the left, as seen from the front (above left), with the other five on the right (above right). Five of them needed mitring to fit into the height allowed - The "C" pipe needed two mitres, so the stopper pointed downwards, and the "F" pipe, mitred once needed an extra long foot so the mitre didn't interfere with the stopper. Allowance had to be made for the largest trumpets whose boots project into their space. All these measurements were taken into consideration in the original design.

Above left: The melody pipes are placed in the centre between the two sections of accompaniments. The two ranks of bourdon are at the back, with the celeste rank facing backwards immediately behind the straight-tuned rank (not tuned when the picture was taken). Above right: In front of the bourdons are the forte ranks - both open flutes, mounted above the slider assembly. They are on an extended board projecting through the façade opening, the piccolo in front and the quint rank behind it. The piccolos are arranged in a curve, as they will become part of the organ's façade.

None of these pipes are stayed in any way, their feet having tapers which fitted into tapered holes. The taper of the feet is very slightly different from the holes, so with a light tap or a twist the pipes are secured. They can be easily removed whenever maintenance is necessary.

Before the pipes were finally fitted, the action needed to be in place so the individual pipe holes could be blown through to expel any dust, and to test the pipes' speech and adjust tuning. A voicing machine is great for getting the various ranks speaking with uniformity, but the wind channelling in the organ can easily upset speech through turbulence and/or pressure loss.

This picture shows the top part of the relay in position. It has short brass tubes fitted ready for the keyframe tubing, and a rail holding the moving part of the window latches. The colour-coded labels indicate the positions of the various notes, to make action adjustments just that bit less tedious.

Above left: The keyframe tubing in position. Also shown are the action bleed holes in plastic-card discs. The holes were finely adjusted after the pipes had been placed in position. Starting with small holes, they were gradually enlarged one-by-one until the correct action repetition was obtained. For each adjustment of the holes, the polycarbonate window needed to be removed and re-fitted, which is why I designed it to be easily done with the latches.

Above right: The keyframe end of the tubes fitted to the tracker-bar of the keyframe, in three rows.

The organ's register control was designed to be operated automatically from the music, but during preliminary assembly I decided to also incorporate a means of manual control. Above left: The manual register control components arranged roughly in relative positions, with the operating knob on the right. Above right: The manual control is fitted to operate the slider through its actuating rod shown projecting through the slot.

Left: the register action is reversed through the vertical lever (backfall) allowing the knob to be pulled out to bring the forte pipework into play, and pushed in to silence it. The knob will be automatically moved whenever the register is changed through the music itself. The elements of this action are connected by small bronze rods (produced on my thread-rolling machine), and fitted with standard classical organ tracker buttons and washers.

Also showing in this picture are small patches of masking tape covering pipe holes whose pipes are not yet fitted - to keep out dust.

Pneumatic register motors are mounted on the front of the distribution board. They were strategically placed to fit between the trumpets. The manual register control can be seen at top right of the picture.

The large holes are for the three smallest trumpets, feeding directly into their boots from the back.

The last pipes to be fitted were the trumpets (above left). They are anchored at the bottom using bolts and captive nuts. Their open ends, pointing downward, speak through the opening at the base of the façade (above right). Their flute helpers can be seen, mounted in the same order to simplify their wind-ways.
Left: Space allowance for the larger trumpets was at a premium, and required careful design planning.

Regulating these reeds was somewhat tricky, especially the longest ones mounted in the corners. As they speak into the space below the organ's floor, the surrounding timber shields them, simulating longer resonators. To reduce the excess "length" I needed to shave away a considerable amount while leaving the front slat at its original length so the bolt mounting could still be used. I had to do that by small amounts at first, replacing the pipes into position with the others around them, trying them on the wind each time, until I got it right. Only then did I finally secure the pipes and their wind supply tubes with a thin smear of Evo-stik, which is easily pulled away whenever the pipes need to be removed. The rubbery glue would still serve to seal the joins when the pipes are re-fitted.

Music

As this organ has an enlarged musical scale based on the popular English 20 note organs, it is unique to this organ, no commercial arranger will accept a job unless there will be at least 5 organs he could sell it to, so I am forced to do it myself.

This is an organ built on traditional lines, and as such is a demonstration of how it used to be done. That's why I decided to not have anything electrical on the organ, so MIDI is out. I specifically wanted to be able to play tunes at random, and not in any specific order, so paper-rolls were also out, leaving cardboard the only option. As this organ was designed on the German style, with a separate trumpet section and a forte register, I went for keyless operation as opposed to the French/Dutch keyed. A keyless keyframe is far simpler in design and construction, which was another good reason for using the keyless system.

I and the famiy have produced a short video showing how the music is arranged and cut: on Youtube. Please feel free to leave comments.

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