The rapid development of the metalworking sector is poorly presented without constant improvement of the used machine equipment. Indeed, it depends on the tools used, how quickly the parts will be sharpened, the quality of the finished product and compliance with the geometry.
Introductory information
Why do I need a chuck for a lathe? It is used to fix workpieces. Thanks to it, the necessary clamping force and centering accuracy are ensured. Lathe chucks can be installed on both special and universal machines. They fasten parts along the axis of the spindle. This allows you to achieve reliable fixation and increase the clamping force in cases where there is a large torque. Due to this, the part does not break and continues to maintain the correct position during processing. The risk of tool breakage is also reduced. All this together allows for high production speed. A lathe chuck is made of hardened steel, although it can also be made of cast iron. They differ from each other in design and purpose. In the Russian Federation, eight standards are provided for them that describe the requirements for the elements.
About classification
Any turning chuck can be attributed to one of two groups: it is either a collet or cam. The former are made with a non / extendable or retractable sleeve that secures the part in the required position. The second do with several movable segments, which are called cams. Thanks to them, parts are fixed. Cams can be used in a large number of operations. They may differ in purpose and design features. If we talk about the classification, then the turning cartridge can be assigned to a specific group depending on one of the indicators:
- The number of cams. Varies from two to six.
- Features of fastening. Located on the inner or outer surface.
- Performance specifics. One-piece, patch or assembly cams.
- Drive used. It can be mechanical or manual.
All this affects the features of use and the intended use for certain functions.
More on cam chucks
Let's go through the most popular options:
- Self-centering two-jaw cartridges. This option is used to fasten complex shaped parts, non-cylindrical and asymmetric workpieces. Lathe cam chucks of this type are distinguished by the ability to fix raw surfaces in the jaws, while ensuring sufficient grip. This product is made of steel and heat treated by moving parts. Thanks to what durable and wear-resistant cartridges are obtained. Among the shortcomings, the fact that there is a high risk of misalignment is worth mentioning. This is due to the wide gap between the rails.
- Three-jaw lathe chuck. The most common option. It can be found in home workshops, industrial production, assembly shops and garages. Usually accompanied by traction drive. Its presence reduces the amount of time required for fixation by about 30-80%. Such optimization allows you to speed up the process. This is especially important in cases where there is a large load. For example, similar is on serial machines. The presence of a mechanized drive allows you to get another important advantage, namely the constancy of the clamping force. Thanks to this, the part does not crash and does not warp at any speed.
- Four-jaw turning chucks. They are used in cases where it is necessary to process asymmetric workpieces, provided that the holes for the bore are on different axes or you need to sharpen a round part outside the center.
Read more about collet chucks
The key working element here is a metal sleeve. It can be divided into three, four or six petals. From their number depends on what maximum diameter of the fixed product can hold turning chucks. After all, metal plates capture the part that is inserted inside the sleeve. They also hold it throughout the entire workflow. Structurally, the collets are divided into feed and clamping. The second feature is the presence of three incomplete cuts on a hardened steel sleeve. The first use spring type petals.