Precision
Cams & Conjugates

A precision cam is a rotating or translating component with a non-circular profile designed to convert rotary motion into a specific programmed output motion — linear, oscillating, or complex. The cam profile is the exact shape that produces the required follower displacement, velocity, and acceleration curve. In automation equipment, cams provide precise, repeatable, high-speed motion sequencing without electronics — packaging machines, textile looms, and assembly automation rely on cam-driven mechanisms for their core motion sequences.

HXC produces four main cam types: Disc cam (plate cam) — flat plate with profiled outer edge, follower rides the edge. Most common type. Barrel (cylindrical) cam — cylindrical body with a groove on the outer surface; follower runs in the groove, allowing positive (closed) drive without spring return. Face cam — profiled groove on the flat face of a disc; follower is pushed axially. Conjugate cam set — two matched cams driving one follower from both sides, eliminating backlash and follower jump at high speed.

Cam profiles are specified by a displacement diagram (follower displacement vs. cam angle, 0°–360°) combined with dwell periods, rise / fall motion laws (simple harmonic, modified sinusoidal, cycloidal, polynomial), and the follower geometry (roller radius, knife edge, flat face). HXC engineers convert displacement diagrams into CNC toolpaths and profile-ground cam geometry. Provide your displacement diagram, motion law, follower type, and maximum cam speed — we calculate the cam profile coordinates.

Production cams require high surface hardness to resist follower wear: D2 tool steel (HRC 58–62): the standard for high-speed, high-load cams in packaging and textile machines — excellent wear resistance. H13 hot-work tool steel (HRC 48–52): for cams operating at elevated temperature (hot forging presses, injection moulding) where D2 would soften. 42CrMo4 induction hardened (HRC 50–55): for medium-speed industrial cams. For prototyping and instruments: Al 7075 (hard anodized) or unhardened tool steel.

CNC profile milling achieves ±0.02 mm. Profile grinding achieves ±0.005 mm — required for high-speed production cams where follower motion accuracy is critical. Coordinate measuring (CMM) verifies the actual profile against the theoretical at angular increments of 1° or less. HXC provides the full CMM profile deviation report with every precision cam order.

The pressure angle is the angle between the cam normal at the contact point and the follower direction of motion. High pressure angle (>30°) causes large lateral forces on the follower stem, leading to binding and wear. Low pressure angle (<30°) requires a larger base circle radius — making the cam larger. The maximum allowable pressure angle is: 30° for translating roller followers; 45° for oscillating followers. The cam designer must balance base circle size (compact cam) against pressure angle (smooth follower motion) — HXC engineers optimise this during DFM review.

A conjugate cam (also called a dual cam or positive cam) consists of two matched disc cams on the same shaft, driving a two-roller follower simultaneously — one cam pushes the follower in one direction, the other cam constrains it in the opposite direction. This eliminates the need for a follower return spring and prevents follower jump at high speed. Standard for high-speed packaging machines (above ~200 RPM) where a spring-return follower would bounce. HXC machines conjugate cam sets as matched pairs, with both profiles ground and measured together.

Open-track barrel cam: the follower rides against the outer surface of the cam groove — requires a return spring. Simpler to manufacture but follower can jump at high speed. Closed-track (groove) barrel cam: the follower runs inside a machined groove, driven positively in both directions. No spring needed, no follower jump, but the groove must be wider than the roller plus clearance. HXC machines both types — closed-track barrel cams are significantly more complex to machine and cost more but are preferred for high-speed applications.

HXC cams are designed for roller followers (most common — IKO, INA, SKF needle roller followers), knife-edge followers (for sharp-profile instruments), and flat-face followers (for high-speed automotive cam followers). Roller followers require the cam profile to be offset (inflated) by the roller radius from the pitch curve — HXC calculates this offset automatically from your pitch curve data.

Prototype (1–3 pcs, 5-axis milled, no hardening): 5–8 days. Profile-ground disc cam, D2, hardened: 10–16 days. Barrel cam (complex groove machining): 14–20 days. Conjugate cam set: 14–18 days. Large cams (>Ø200 mm): add 3–5 days. Rush production available — contact us with your deadline.

Yes — HXC accepts cam profiles as: DXF 2D cam outline; CSV / Excel table of (angle, radius) or (angle, displacement) pairs; STEP / IGS 3D cam model; or a displacement diagram image — we digitise and calculate the profile. We also design cams from scratch from your motion requirements: rise / dwell / fall timing, motion law, follower geometry, and maximum cam speed.