After bruising his knuckles on one of modern step stool woodworking gear old-fashioned spanner adjusted drill chucks, he developed a chuck in which the jaws moved axially in inclined slots. It self supports on itself. Please visit www. It can be assembled using 10 wood screws to enable disassembly for storage, or glued together as a permanent structure, as you wish. Here is an easy Spoon Rest project with a twist - this Midern version features a hinged frame that swings up and over the main spoon bowl area to provide a built-in spoon handle support!

Many chucks have removable jaws often the top part is removable leaving the base or 'master jaw' assembled with the scroll , which allows the user to replace them with new jaws, specialised jaws, or soft jaws. Soft jaws are made of soft materials such as soft unhardened metal, plastic, or wood. They can be machined as needed for particular setups. The typical interface between the master jaw and the removable jaw is a matching pair of serrated surfaces, which, once clamped by the mounting screws, cannot allow relative slipping between the two parts.

A collet, one type of chuck, is a sleeve with a normally cylindrical inner surface and a conical outer surface. The collet can be squeezed against a matching taper such that its inner surface contracts to a slightly smaller diameter, squeezing the tool or workpiece whose secure holding is desired.

Most often this is achieved with a spring collet, made of spring steel , with one or more kerf cuts along its length to allow it to expand and contract.

An alternative collet design is one that has several tapered steel blocks essentially tapered gauge blocks held in circular position like the points of a star, or indeed the jaws of a jawed chuck by a flexible binding medium typically synthetic or natural rubber. The Jacobs Rubber-Flex brand is a name that most machinists would recognize for this type of collet chuck system. Regardless of the collet design, the operating principle is the same: squeeze the collet radially against the tool or workpiece to be held, resulting in high static friction.

Under correct conditions, it holds quite securely. Almost all collet chucks achieve the radial squeezing motion via moving one or more male-female pairs of tapered conical surfaces axially, which produces the radial squeezing in a highly concentric manner.

Depending on the collet design, it can be either pulled via a threaded section at the rear of the collet or pushed via a threaded cap with a second taper into a matching conical socket to achieve the clamping action. As the collet is forced into the tapered socket, the collet will contract, gripping the contents of the inner cylinder. The axial movement of cones is not mandatory, however; a split bushing squeezed radially with a linear force—e.

Thus only in toolroom contexts, such as machine tool tooling creation and setup, is this common. One of the corollaries of the conical action is that collets may draw the work axially a slight amount as they close.

Collet chuck systems that make no provision to prevent this draw-in are often called draw-in collet chucks, in contrast to systems which circumvent this movement, usually by pushing the tapered closing ring toward the collet rather than pulling the collet into the ring.

Such non-draw-in types are often called "dead-length" or "non-draw-in" collet chucks. Draw-in is not always a problem, but avoiding it can be helpful on some work where failing to account for it might result in inaccuracy on part overall length, shoulder lengths, etc.

Collets are most commonly found on milling machines , lathes , wood routers , precision grinders , and certain handheld power tools such as die grinders and rotary tools. There are many different systems, common examples being the ER , 5C , and R8 systems. Collets can also be obtained to fit Morse or Brown and Sharpe taper sockets. Typically collets offer higher levels of precision and accuracy than self-centering chucks, and have a shorter setting up time than independent-jaw chucks.

The penalty is that most collets can only accommodate a single size of workpiece. An exception is the ER collet which typically has a working range of 1 mm about 0.

Collets usually are made to hold cylindrical work, but are available to hold square, hexagonal or octagonal workpieces. While most collets are hardened, "emergency" collets are available that can be machined to special sizes or shapes by the user.

These collets can be obtained in steel, brass, or nylon. Step collets are available that are machinable to allow holding of short workpieces that are larger than the capacity of normal collets.

The rotary force is supplied through wedges that fit into two or three open grooves. The hammer action actually moves the bit up and down within the chuck since the bit is free to move a short distance. Two sprung balls fit into closed grooves, allowing movement whilst retaining the bit.

SDS relies on a tool having the same shank diameter as the chuck; there are four standard sizes:. Many SDS drills have a "rotation off" setting, which allows the drill to be used for chiselling. The name SDS comes from the German steck, dreh, sitzt insert, twist, fits.

Commercial production machining now makes use of increasingly advanced chucks which have not only indexable positioning but also indexable clamping. The clamping is often done with each pair of jaws consisting of one fixed jaw and one movable jaw hydraulically actuated , thematically similar to advanced milling vises. This method of clamping brings the high precision and repeatability of such vises to a chucking application.

Such chucks offer the centering precision of traditional independent-jaw chucks with the chucking speed and ease of traditional three-jaw self-centering scroll chucks. They have expensive initial cost compared with traditional chucks , but such initial cost pays for itself and then lowers ongoing marginal costs in commercial production-run environments.

It is also possible nowadays to build CNC chucks in which the position and clamping pressure of each jaw can be precisely controlled with CNC, via closed-loop positioning and load monitoring. In essence, each jaw is one independent CNC axis, a machine slide with a leadscrew , and all four or six of them can act in concert with each other. Although this idea is conceptually interesting, the simpler chucking systems mentioned in the previous paragraph are probably a marketplace winner over this alternative for most applications, because they supply the same capabilities via a simpler, less expensive solution.

Used for holding ferromagnetic workpieces, a magnetic chuck consists of an accurately centred permanent magnet face. Electromagnets or permanent magnets are brought into contact with fixed ferrous plates, or pole pieces , contained within a housing. These pole pieces are usually flush with the housing surface.

The part workpiece to be held forms the closing of the magnetic loop or path, onto those fixed plates, providing a secure anchor for the workpiece. Commonly used for holding silicon wafers during lithography processes, an electrostatic chuck comprises a metal base-plate and a thin dielectric layer; the metal base-plate is maintained at a high-voltage relative to the wafer, and so an electrostatic force clamps the wafer to it.

Electrostatic chucks may have pins, or mesas, the height of which is included in the reported dielectric thickness; a design by Sandia National Laboratory uses a patterned silicon-dioxide dielectric to form the pins. Dongguan Ginotti sofa Furniture Factory company limited. The "fall" Modern Woodworking Wagner 80 of Yihua's life is inseparable from its illegal actions and the declining main business. Uniqlo enters the home furnishing field: the first series of products such as pillowcases and bed sheets were launched.

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