The cam indexer is the main drive component of the entire mechanism and is essential for ensuring the mechanism completes its rotation. The grooves on the curved cam surface rotate, transferring motion to the closely fitted rollers, allowing them to move freely on the groove surface. The turret roller needle rotates under the action of the ribs, receiving force from the rollers and needle rods. The cam follower mechanism can be designed to meet almost any input-output relationship within its range of motion. For some applications, cam and linkage mechanisms can serve the same purpose. For industries where both are applicable, cams are easier to design than linkage mechanisms, and cams can also perform many tasks that linkage mechanisms cannot.

Many engineers differentiate between cam drives and turbine governor rod drives in terms of advantages and disadvantages. In fact, professionals can easily distinguish between friction drives and semi-rolling drives. Cam friction drives are inefficient, while rolling drives demonstrate their advantages. Intermittent positioning precision indexers are also the best choice. Drives such as DD also produce cumulative errors, while cam indexers effectively avoid this. The motion law of the indexer cam is such that in a disc cam mechanism with a roller-type concentric direct-acting follower, the follower performs four actions sequentially (rise-stop-fall-stop) as the cam rotates one revolution. The relationship between the follower displacement s (or stroke height h) and the cam rotation angle (or time t) is called the displacement curve. The follower stroke h has a push stroke and a return stroke. The cam profile curve is determined by the shape of the displacement curve. In some machines, the displacement curve is determined by the process, but generally only the stroke and the corresponding cam angle are determined according to the work requirements, while the shape of the curve is selected by the designer, and there can be various motion laws. Traditional cam motion laws include constant velocity, constant acceleration-constant deceleration, cosine acceleration, and sine acceleration. Constant velocity motion laws, due to sudden changes in velocity, produce strong rigid impacts and are only suitable for low speeds. Constant acceleration-constant deceleration and cosine acceleration also have sudden changes in acceleration, causing flexible impacts, and are only suitable for medium and low speeds. The sine acceleration motion law has a continuous acceleration curve without any impact and can be used for high speeds.

To prevent the acceleration and rate of change of velocity of the cam mechanism from differing too greatly, and considering factors such as momentum, vibration, cam size, spring size, and process requirements, other motion laws can be designed. Commonly used motion laws are combinations of several curve segments, such as modified sine acceleration, modified trapezoidal acceleration, and modified constant velocity motion laws. Electronic computers can also be used to arbitrarily combine various motion laws. Polynomial-represented motion laws can also be used to obtain a continuous acceleration curve. To obtain the most satisfactory acceleration curve, an acceleration curve can be arbitrarily given in numerical form, and then the displacement curve can be obtained using the finite difference method, and finally the cam profile can be designed.

Some automatic machines usually use several cams working together. To ensure that the actions controlled by each cam are coordinated, a correct motion cycle diagram must be prepared before cam design. Reduce surface roughness. The working conditions of the cam are dry air, clean lubricating oil, or lubricating oil with various additives. The selection of lubricating oil viscosity and oil supply method should consider the shape of the follower and the cam speed. The material matching of the cam and follower should be appropriate. For example, hard steel and cast iron are inexpensive and suitable for high-speed sliding; hard steel and phosphor bronze have low vibration and noise and can compensate for inaccuracies in the profile. Cast iron and cast iron pairs have acceptable results.

The material requirements for indexer cams are quite stringent. The main reason is that the nature of the cam's motion dictates that the cam must have a certain hardness while maintaining overall toughness to prevent deformation during transmission. Combinations such as hard nickel steel and hard nickel steel, or soft steel and soft steel, are not effective.

For geometric parameters, lubrication, materials, and surface roughness, elastohydrodynamic lubrication theory can be used for comprehensive calculations to reduce wear. In addition, the selection of materials is also meticulous, including the thermal coefficient used in material selection, which should be considered to make the material deformation coefficients of various mechanisms closer, which is more beneficial to ensuring accuracy.