A range of dovetail and specialist jaws is available to fit the Patriot chuck, as listed below and the sizes are
largely self-explanatory. In all cases, the jaw description (e.g. 1in. (25mm) jaws) refers to the nominal size of dovetail recess into which the jaws will fit, to hold work in
"expansion mode" with the jaws at their "perfect circle" position. Of course, all chuck jaws of the dovetail type
should ideally be used at their "perfect circle" diameter to ensure the best possible workholding, but a little accommodation to allow for slightly over-zealous cutting of the mounting dovetail is always welcome!
The jaws mounted on a Patriot chuck can be opened out up to an inch (25 mm) above this nominal size but the fit of the jaw
into a circular recess will not be exact at such larger openings. An innovation introduced by
Sorby in their chuck jaws is the incorporation of a "gripper" section inside the jaws set, behind the dovetail section, designed to impart superior hold on deep spigots - for instance when
turning goblets, vases and similar forms which may project a long way out of the chuck jaws.
A table of jaw dimensions is show on a separate page of this site.
If gargantuan grip is what you seek then the Deep Grip jaws may be what you are looking for. These jaws will expand into a 108 mm (4.25") to 133 mm (5.25") recess
as well as gripping a 97 mm (3.81") to 122 mm (4.81") foot.
At the other end of the size scale but equally renowned for tenacious grip are Pin Jaws. These jaws are commonly used to provide a first fixing of the workpiece, especially if the
workpiece has an uneven surface such as a natural bark edge. Simply drill a 25 mm (1 inch) hole in the workpiece and the jaws expand into the hole, holding the work firmly.
They also feature a fine dovetail recess of 0.53 in (14 mm) internally with a maximum opening of 1.53 in (39 mm) and an external dovetail of 1 in (25 mm) nominal size, expanding to 2 in. (50 mm).
For finishing the base of work after turning, the Bowl
Reversing jaws make life very simple. The workpiece is held onto these aluminium jaws by eight non-marking rubber buttons which work equally effectively in expansion or compression mode.
It is often useful to be able to de-mount and later, re-mount workpieces. When using a dovetail formed on the workpiece, this often proved to be a frustrating exercise as re-aligning the workpiece can be very
troublesome. The use of Faceplate Rings overcomes this
limitation and makes accurate re-mounting of work very easy. These rings are available to fit the 50 mm dovetail jaws with a choice of two outside diameters, allowing a ring appropriate to the
size of the workpiece to be selected. Faceplate rings are a real boon in situations where work must be frequently de-mounted and re-mounted, such as in education, where
a ring attached to the workpiece means that each student can rest assured that the work will re-mount straight and true the next time it is their turn on the lathe.
Please not that the mounting jaws (also known as carrier jaws, base jaws, jaw sliders) of the Patriot chuck cannot easily be removed and re-inserted for "jaw swapping". The design of the
chuck requires that jaws are swapped by removing the mounting screws and swapping the dovetail jaw on the mounting jaw. Buy yourself a decent hex (Allen) key and that's no hassle at all!