The making of the dog
It must be made in hard wood (maple, embed, boxwood ... ) and its making must aim at its ughtness. Its approximate dimensions are given by the opposite diagram.
Its height, approximately 8 mm, should not be too large, so that the string forms a roughly flat angle at the level of the edge of the dog. The distance from the mobile foot to the foot used as pivot (15 mm approximately) is significant for the sonority and the facility of play : the string being at the base of the mobile foot, it must make, an almost flat angle on the edge of the wheel. However, if the length of 15mm is not appropriate, it is necessary to move the fixed rest of the fly (only stuck). The tail of the dog which guides it in its movement must be very thin (1 mm approximately), as well as the slit made in the fixed rest. The shoulder which is used both as a stop and pivot with the dog must be very neat and laid on all its length.
The dog must apply exactly to the table, on all its surface, like any rest. For that, it's convenient to rub it on a plane surface covered with fine sandpaper.
One slightly modifies sonority by moving the string on the higher edge (1mm of displacement has many effects). The personal taste is the only judge in the matter.
The angles formed by the string on the wheel, the dog, and the small string of tension (or drawing) side, must be very open. If it is necessary to tighten the tie very strongly to make the dog sound, it is better to move the point where the trumpet is fastened on the fish-plate (task to be made by a specialist).
A good dog is not something easy to make. By following these simple recommendations one is sure to make a dog wich works well. But it is necessary to work out several of them to find one which is right, with a beautiful sonority.
Indications and precise for the maintenance and the adjustement of the following elements :