by Melvyn Wright
I first thought of the idea of a 2-register John Smith Busker Organ in 2009.
Two years later I experimented with the idea, made up a working prototype
slider unit, and published an article about it on my web site and Busker
Forum. See my original article.
For various reasons, I wasn't able to build a working organ at the time,
using my revolutionary idea, because it meant starting a new build from scratch;
and I didn't have the time.
I encouraged other people to take up my idea, but I don't know anybody who
has built a 2-register organ - until now! Chris Richmond has just built
such an organ, and he has very kindly submitted this article to explain it
in detail. I must say he has made an absolutely marvellous job
of it, and it is difficult to believe that behind this facade is a John Smith
Yes this IS a John Smith Busker Organ! The 2 pipe ranks at
the side are dummies, but all the rest are working pipes.
2-Register Busker Organ - Chris Richmond
In late October, I visited a local firework display in my home County of
Norfolk. For several years now, a regular feature of the event had been the
68-key Bursens street organ owned by Teddie Cushing, son of the late George
Cushing who founded the nearby Thursford Collection. This particular organ
has always had a special place in my heart after seeing it at numerous events
throughout Norfolk during my childhood. The bright lights, animated wooden
figures and the colourful sounds that emanted from it fascinated me each
time I saw it.
Teddie Cushing's 68-Key organ built by a then-elderly Arthur Bursens in
|On this more recent occasion, I plucked up the courage to ask Teddie
if I could take a look inside to see how it all worked, to which he simply
replied, "You'll have to climb up that ole stepladder". In the back of his
lorry overseeing the operation of the organ was the one and only Bob Ince-
the man who maintains all of Thursford's mechanical organs, who was more
than happy to explain how it all worked. I stood there for ages, gazing at
the large belt-driven wheel and watching the cardboard books roll through
the keyframe. (During all this, my partner was (im?)patiently stood outside
in the freezing cold) Studying the simple principles of how it all worked,
I was convinced that I could recreate something on a much smaller scale,
and so I eventually came across the plans for the John Smith Busker organ,
which seemed like a great place to start.
After carefully studying the plans and watching the provided DVD, I soon
realised that there was the potential to enhance this simple machine into
something a little more elaborate. I started sketching-up ideas for decoration
inspired by the style of that particular Bursens organ, and so I began to
develop a plywood front, which would almost represent a scaled-down version
The rear of the large front panel of my Busker organ. Note the two ranks
of "dummy" pipes. These will form a decorative screen with the bass pipes
|Curious to see other people's ideas, I stumbed across Melvyn's website
and the collection of articles and saw that Melvyn himself had devised a
concept of a Busker organ with two registers and twenty-nine pipes- something
which had not, to Johm Smith's own knowledge, been done before. The result
of Melvyn's experiment was a slider mechanism which was actually too large
to fit within the specified dimensions of the Busker shell.
As the construction of my own Busker developed, I eventually got to a point
where I could start experimenting with this idea and created a very primitive
slider mechanism, which was split into two seperate sliders to see whether
two pipes could sound at once (I do love the sound of a good bourdon celeste-
something which the Bursens organ had.) This slider was never a success.
Apart from it being rather crude with several air leaks, Melvyn soon informed
me that with the exception of the top few melody pipes, there is not sufficient
air travelling through the hole in the paper to sound two pipes at once.
The very crude "Slider MkI", which featured two independently-controlled
sliders, was unsuccessful.
|A couple of months later, I had another go at creating a slider (Slider
MkII). After studying Melvyn's photographs, I borrowed a friend's pillar
drill and drilled channels into a solid block of wood, which was then suspended
from the main pipe shelf by three wood screws forming a sandwich around the
slider board, which could be slackened off slightly to allow for the degree
of free movement. All of the pipes were fed from beneath, with the holes
in the channelled bottom block drilled in the centre, to eliminate any bias
of differing pressure in the holes of the slider. When I tried an initial
test, this slider actually proved to work.
However, one major flaw was that the pipe shelf I had made was too thin and
would bow slightly in the middle. Because everything was still at the
experimental stage, the pipes leading from the tracker bar were cut long,
and would cause the bowed centre of the pipe shelf to "bounce" as the pipes
came into contact with the reservoir.
The three main parts of "Slider MkII", which appeared to work, but wasn't
the neatest or most robust design. From top: Pipe shelf (with strengthening
baton), hardboard slider, bottom block with drilled channels.
|Whilst attending the Diss Organ Festival a week or so later, I ended
up discussing my idea with a chap called Nicholas Simons, member of the Musical
Box Society of Great Britain, who suggested one or two ideas and pitfalls
of sliders. Reflecting on what was said, and not being particularly satisfied
with my rather flimsy creation, I scrapped it and came up with something
a little more robust, which I will now share with you in a bit more detail.
In my collection of wood was a pine shelf of about 15mm in depth and 68mm
in width. Now, I know pine isn't perhaps the best wood due to its porous
nature, but I was determined to give it a go (this became Slider MkIII) I
marked up all the holes for the pipes using "Slider MkII" as a template.
Also in my collection was a thin piece of hardboard with a lovely veneer-effect
coating on one side, which had a rather slippery feel, and was resistant
to paint or anything else that made contact with it. Despite hardboard also
not being ideal, the piece was the exact same width as the piece of pine-
almost like they were destined to fit together! The majority of the hardboard
became the slider unit. This had to be cut at such a size that the ends would
only slide one hole's width along AND not foul the holes of the adjacent
accompaniment pipes. It is also important to leave an area which will protrude
from the slider unit so that a "stop action" can be attached to it in order
to operate the slider from the outside of the organ. Please note that the
length of the pipe shelf was cut to fit within the original specifications
of the Busker organ plans.
To help enclose the sliding hardboard part, a pair of wooden batons were
glued to the edges along the lengths of the pine pipe shelf. The critical
space for the depth of the slider was measured quite simply by setting the
pine shelf on top of the hardboard and clamping the batons to it. Once the
glue was dry, the whole shelf assembly was cut to size. Obviously the batons
would only be required to surround the space covered by the slider. However,
for neatness, the frontward baton was left complete along the entire length
of the pipe shelf. The rear had to be cut to allow the space for the moving
con-rods and reservoir transfer pipe.
A representative exploded drawing of the three main components of the
(Click for larger view)
|However, once the batons were fitted, it was clear that the whole assembly
would then protrude outwards from the front of the organ, and complete new
sides had to be made to allow for the added depth. This may not necessarily
be the case for all organs if the pipe shelf and baton assembly is narrower
than mine (but please see the point about space between the ranks of pipes
towards the bottom of this article).
In order to create the slider assembly, I used the remainder of the hardboard
to "build-up" the area surrounding the sliding part and the rest of the pipe
shelf. The hardboard was then covered with a paper gasket to allow for the
tiniest bit of clearance to enable the slider to slide without having too
much air leaking from it.
This was then topped with a piece of plywood cut to the exact same size as
the pine shelf/baton assembly and sanded down flush. At this point, I marked
the holes out onto the plywood using "Slider MkII" as a template so that
the holes would line up and began to drill-out the vertical holes. For the
accompaniment pipes, I drilled 6mm holes right the way through the assembly
to allow for pipe connections above and below the pipe shelf (the brass inserts
from the pipes themselves slot down into the holes, while the brass inserts
from the plastic tubing slots in from underneath).
For the melody pipes, I drilled down into the pipe shelf about three-quarters
of the way to the bottom, forming a blanked-off hole. 2 rows of 9 holes need
to be drilled to enable two ranks of pipes. It is an idea to screw the whole
assembly together with the slider in place at one end of its travel and drill
one rank of holes, then sliding it to the other end of its travel, re-screwing
it all together and then drilling the second rank of holes.
The resulting screw holes through the slider give an indication of the travelling
area of the slider and an enlarged channel should be filed between the holes
allowing for slider travel as well as adjusting the tension of the slider
and more importantly, keeping the unit assembled. I also added screws to
the areas of the accompaniment pipes, which hold the assembly together,
eliminating the need for glue so that the unit can be dismantled easily and
without mess and damage.
Unlike "Slider MkII" where the holes for the plastic tubing were all drilled
underneath the bottom block, I decided to drill the holes for the 9 melody
pipes to the rear of the assembly (through the rear baton). I carefully marked
out the holes using a set-square to ensure the channels would align with
the top holes and drilled 6mm holes through the side of the assembly until
the drill bit had reached the furthest hole towards the front of the unit.
Once all holes had been cut, I then cleared the channels and soaked them
in water/PVA glue mix to seal them. One thing I did learn from this is not
to over-do it, as the wood can swell and the remaining mix dries up and shrinks
the holes a bit. I then re-drilled the holes to 6mm , as it had a detrimental
effect on the airflow to the pipes.
I then plugged the holes in the side of the block with short lengths of 6mm
brass tubing to attach to the plastic tubes leading from the tracker bar
(which would be considerably shorter in length and wouldn't foul the movement
of the reservoir as they did when entering from underneath in "Slider MkII".
The tubes for the accompaniment pipes were still connected from underneath
the pipe shelf, as if they were connected from the rear, the tubing would
foul the action of the con-rods and also clash with the positioning of the
reservoir/bellows transfer pipe.
Prior to the final assembly of the slider unit, it was essential to sand
down all sliding parts with very fine wet & dry paper to reduce as much
friction as possible on the sliding surfaces. To assist the hardboard slider,
I coated the previously untreated underside with a couple of coats of gloss
spray paint to smoothen it up. It is worth letting this dry thoroughly for
at least a couple of days to prevent it sticking once inside, then abrade
it with the fine wet & dry paper when it has dried solid.
Once the whole unit was assembled, the centre screws were tightened hard
before slacking them off slightly. this is to help eliminate any bows in
the plywood or hardboard slider part (of which there was some warpage apparent,
which leaked a tiny amount of air at the outer edges).
Once the unit was assembled and installed, the top holes for the melody pipes
pipes were fitted with 6mm brass tube inserts and the pipes pushed onto them.
During the testing of the unit, there was one apparent problem, which mystified
me at first... If your slider unit is as compact in width as mine, there
isn't much space between the two ranks of melody pipes- especially between
the larger pipes, where the lack of room actually inhibits the voicing of
the pipe. Melvyn suggested turning the rearmost rank of pipes to face backwards,
which completely solved this problem!
The whole unit was mounted half way up the front of the organ on blocks attached
to the sides of the organ Because my design was not bound by height, the
largest pipes stick up a considerable distance above the top of the pressure
box. The unit is fixed by screws entering the ends of the pipe shelf through
the sides of the organ. Once the organ front is removed, the pipe shelf/slider
assembly is easily removed and can fold down whilst still attached to the
plastic tubing, giving access to the pressure box take-up spool and idler
"Slider MkIII" removed from its shelf showing the plastic tube connections
gaining access to the drive wheels. The stop action mechanism can be seen
towards the right. Metal washers are glued to the hardboard slider to prevent
wear and provide strength.
|The slider mechanism is controlled by the means of a stop on the side
of the organ. Due to the construction of a bulky front, which uses some of
the organ's depth, I incorporated a pivoting linkage mechanism, which uses
available space inside the organ with a pivot mounted on the underside of
the pressure box, leading to a rod, which exits the side of the organ some
distance behind the rear of the organ front. This took some experimenting
to get it to work as desired. The action perhaps isn't perfect, but it works!
So, after a few months of experimentation and determination, I can now say
that I am the first person to successfully construct a Busker organ with
two registers and 29 pipes!
Unfortunately Melvyn never did fit his slider unit back into his organ.
However, I thank him greatly for inspiring me to develop his idea and
for his helpful advice throughout the process.
The front of my Busker organ with all pipes now in position. Notice how
the left and right ranks of "dummy" pipes compliment the bass pipes behind
and gives the instrument the impression that it is larger than is actually
is. The elaborate patterns are actually waterslide transfers carefully traced
on the computer from original photographs of the Bursens organ on which the
front is based. I'm no wood carver, so the textures on the scrollwork were
inscribed with an electronic engravers pen.
The latest addition - A 'Mockenspiel'!
I have recorded a video, which can
be seen here.
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