Jig borer

The jig borer is a type of machine tool invented at the end of World War I to enable the quick and precise location of hole centers.

The result is a machine designed more for location accuracy than heavy material removal.

A typical jig borer has a work table of around 400 by 200 millimetres (15.7 in × 7.9 in) which can be moved using large handwheels (with micrometer-style readouts and verniers) on particularly carefully made shafts with a strong degree of gearing; this allows positions to be set on the two axes to an accuracy of 0.0001 inches (2.5 μm).

The jig borer was a logical extension of manual machine tool technology that began to incorporate some then-novel concepts that would become routine with NC and CNC control, such as: Franklin D. Jones, in his textbook Machine Shop Training Course (5th ed),[4] noted: Several innovations in the development of the jig borer were the work of the Moore Special Tool Company, such as the adoption of hardened and accurate leadscrews, formed by grinding, rather than a soft leadscrew with a compensating nut.

[2] The technological advances that led to the jig borer and NC were about to usher in the age of CNC and CAD/CAM, radically changing the way people manufacture many of their goods.