Hi Folks -- It seems that I might be doing it wrong.  When making pipes,
are they cut true to speaking length before the front is glued on,
or/and are the grooves cut overlong to allow for any shortening when
tuning the pipe?

I was advised to cut the grooves when the pipes had been cut to length
with the front glued on, using a fine toothed hacksaw blade.  I had
limited success using a piece of blade on it's own as the flexibility
in the blade tended to follow the wood grain.

I have overcome this problem by attaching the blade to a strip of wood
with double sided tape, allowing the teeth to protrude below the strip
the depth of the groove to be cut.  This method requires that two tools
are made, left and right handed.  The strip of wood holds the blade
straight and the protrusion controls the depth.  I also remove the set
from one the side of the blade to reduce blade thickness this will also
allow the blade to run flat against the side where the slider is to be
fitted.

It requires but a few strokes of the blade to cut the grooves and
does not require the setting up of power machinery.  I try to keep
the grooves as short as possible so as not to reduce the glued area
on the pipe joints.

Perhaps greater use of mechanisation if you need to do hundreds.
Use the method that suits your facilities.

Arthur Nichols
West Midlands, UK