Barrel Chuck
Overview
Barrel Chuck
The barrel chuck, also known as a spring chuck, is employed to clamp small pieces of wood, especially those which are oddly shaped.
Usage Notes
These comments are from Paul N. Hasluck's The Wood Turner's Handybook.
To use this chuck, the ring is first pressed on to the jaws moderately tight, so that it holds them firmly. A recess is then turned in the end very slightly smaller than the diameter of the object to be chucked; the ring is then pushed towards the front end, thereby allowing the jaws to open. The work is put into the previously turned recess, and there securely fixed by pushing the ring back till the jaws clip it firmly.
The ring is often driven on by slight blows at various points of its circumference, always remembering to get it to run quite true.
This chuck is used principally for work which has already been turned true at some part, by which it may be conveniently chucked.
Notes on making one
These comments are from Paul N. Hasluck's The Wood Turner's Handybook.
The drawing above shows a chuck with six grooves, but the number is immaterial. Some workmen use those with only one saw-cut, dividing the chuck into two parts, giving only two jaws. This is undesirable, as the work so chucked is not held firmly. Three jaws would act very well, but it is difficult to cut only three saw kerfs, and for that reason six is the number more generally made. Good sound boxwood is the best material from which to make such chucks, and at the termination of each saw-cut a hole should be drilled. This not only lessens the liability to split, but also, by decreasing the amount of material near the butt end, makes the chuck more flexible at that point-a desirable quality.
In order to ensure the jaws bending near to the butt end, the interior of the chuck should be hollowed out where the holes are bored. This method of reducing the substance of the wood is a better one than that of drilling large holes, because it reduces the strength in the right direction, and does not make the chuck weak, as is the case with large holes.
The outside of this chuck is turned slightly conical, so that the metal ring (shown in the figure above), when forced on it closes the points of the jaws, thereby gripping any work that may be placed within them.
The range of motion in the jaws of this form of chuck is not very great, and hence it becomes necessary to have several spring chucks in accordance with the various sizes of work to be executed.
In order to prevent the wood from splitting, an iron ring is often put around it at the butt end. It is important to see that the ring which binds the staves together runs true, as, if otherwise, the jaws are brought together unequally, and the work chucked in them will be eccentric.
The inside of the ring should be rounded, so that its edge will not catch and cut into the surface of the chuck.
More Information
Books and Papers
- Turning and Mechanical Manipulation, Vol. 4 - Hand Or Simple Turning: Principles and Practice, 1881, by John Jacob Holtzapffel
- The Wood Turner's Handybook, 1887/1901, by Paul N. Hasluck ( eBook)
|
Disclaimer: eMail comments to me at OTBookOfKnowledge @ Gmail.com. The process of woodturning involves the use of tools, machinery and materials which could cause injury or be a health hazard unless proper precautions are taken, including the wearing of appropriate protective equipment. |