Making the Pipes
1) Building Pipes
One of the most interesting things in the way John Smith builds the pipes
of his busker organ is that he uses a scale which doesn't need difficult
measurements. But one difficult thing remains: How to cut perfect parallel
sides for the four main parts of a pipe (bottom and inside partition are
cut from one of these parts). Here is a method which doesn't need
measurements, which is quick, safe and needs very little preparation.
Preparation:
Take a board, as long as the longest pipe (about 60cm), 10 to 20cm wide.
Add a side along the board (glued or nailed). This side overlaps the
board by about 1cm. That's all!
Cutting Sides:
Find a bit of balsa sheet (1mm thick). Using the paper scale, mark
this sheet to the internal (or external) width. Cut the sheet square on the
mark (about 10mm) then cut along this small rectangle in two parts which
will make your cutting guides.
Take the sheet of balsa for pipes, put it on the board against the side.
Put the guides at each end of the board and lay the rule. Firmly
applied, you can run your scapel along.
Of course both opposite sides of pipes are prepared in only one cut, as the
only important precision needed is to get them the same width. The
60cm board allows this for all the front pipes (longest is 31cm) but not
for the bass pipes.
2) Pipe's Appearance
The front of J. Smith pipes shows the gluing line of the sides. It
is hardly visible with balsa wood, but unsightly with other sorts of wood.
Of course you can apply a veneer on balsa, but why not make a long
upper lip which covers the whole front of the pipe. It gives the
traditional aspect with a nice look. This cover will be glued and
side-sanded after tuning. While tuning, use rubber bands only near
the lip to be sure it is firmly applied against the aperture.
3) Hard Balsa
You can find different qualities of balsa at this French provider
HEIMA. They sell
3 qualities of balsa wood: A very light one - COLIBRI; a standard one - CLASS
A; and a NAVAL quality (for ship models). The last is a little
heavier and harder (but still easy to work) and much cheaper than other
qualities!
Jean NIMAL |
