The trammel is used when the distance between the points to be reached is too great for the ordinary dividers. The trammel points are clamped to a beam of sufficient length to enable them to be set the required distance apart. They may be bought plain, as in Fig. 66, or with one point adjustable, as in Fig. 67. The points are removable for the insertion of a pencil socket and pencil when needed.
For very accurate work, an excellent tool of this kind is illustrated in Fig. 68. The beams furnished are 4 inches and 13 inches in length. By the use of the cone center V, which may be substituted for the regular point center, the tool can be used for scribing a line around any hole already bored - sometimes a matter of great convenience. The complete set includes the pen, pencil, straight and bent points, and the cone center, as shown in the cut.
Fig. 66. Plain Trammel Points.
Fig. 67. Trammel with Adjustable Points.
Fig. 69. Accurate Trammel Set.