INDUSTRY COMPONENT

Star Points/Arms

Star points/arms are precision radial extensions on star wheels that engage with mating components to transfer motion in indexing and conveying systems.

Component Specifications

Definition
Star points or arms are the protruding radial elements of a star wheel (also called Geneva wheel or Maltese cross mechanism) that precisely interface with slots or pins on a mating component. These components convert continuous rotary motion into intermittent or indexed motion through controlled engagement and disengagement cycles. They are critical for timing, positioning, and material handling in automated machinery where precise start-stop motion is required.
Working Principle
Star points/arms operate on the Geneva mechanism principle: as the driving wheel rotates continuously, its pin engages with a slot on the star wheel's arm, causing the star wheel to rotate a fixed angular distance (typically 90°, 120°, or 180°). The curved profile of the arm ensures smooth entry and exit of the driving pin while providing a locking surface during dwell periods to prevent unwanted movement. This creates precise intermittent motion with controlled acceleration/deceleration profiles.
Materials
Typically manufactured from hardened alloy steels (AISI 4140, 4340), stainless steels (304, 316), or engineered plastics (POM, PEEK) depending on load, speed, and environmental requirements. Surface treatments include nitriding, carburizing, or hard chrome plating for wear resistance.
Technical Parameters
ParameterTypical rangeNotes & selection driver
Backlash<0.1°
Maximum RPM50-300 RPM
Diameter Range50-500 mm
Indexing Angle90°, 60°, or 45° respectively
Number Of Arms4, 6, or 8 (most common)
Torque Capacity10-500 Nm
Positioning Accuracy±0.05° to ±0.5°

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards
ISO 9409-1, DIN 5480, ISO 2768-mK

Parent Products

This component is used in the following industrial products

Engineering Analysis

Risks & Mitigation
  • Wear and fatigue failure at engagement points
  • Misalignment causing jamming or premature wear
  • Backlash accumulation affecting positioning accuracy
  • Material fatigue under cyclic loading
FMEA Triads
Trigger: Insufficient hardness or improper heat treatment
Failure: Premature wear at engagement surfaces
Mitigation: Specify appropriate material hardness (HRC 50-60 for steel) and implement regular wear inspection schedule
Trigger: Misalignment between star wheel and driving mechanism
Failure: Binding, jamming, or catastrophic failure
Mitigation: Implement precision alignment procedures during installation and use alignment verification tools
Trigger: Excessive operating speed beyond design limits
Failure: Impact damage or fatigue cracking
Mitigation: Install speed monitoring devices and adhere to manufacturer's maximum RPM specifications

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance
±0.05mm on critical dimensions, angular tolerance ±0.1°, surface finish Ra 0.8-1.6μm on engagement surfaces
Test Method
Coordinate measuring machine (CMM) verification, hardness testing (Rockwell C), dynamic testing under load at operating speeds

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation
Request current drawings, revision history, and a signed specification sheet.
Manufacturing capability
Verify equipment lists, process limits, capacity, and representative production evidence.
Inspection readiness
Confirm test methods, calibrated equipment, sampling plans, and traceable reports.
Supplier transparency
Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Star Points/Arms

Manufacturer profiles associated with Star Points/Arms.

Sourcing Star Points/Arms from China?
Tell us your specification and target quantity — we will match it against manufacturer records and come back with the factories that fit.
Request manufacturers We manufacture this

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Related Components

Upper Tool (Punch)
Upper Tool (Punch) is the active forming component in metal plate bending machines that applies precise downward force to create bends in sheet metal.
Main Frame
The main frame is the primary structural component of a hydraulic press, providing rigidity and stability to withstand high compressive forces during metal forming operations.
Shaft Bearing
Precision component supporting rotating shafts in vibration motors to reduce friction and maintain alignment.
Seal Groove
Precision-machined groove in aluminum bearing housings designed to accommodate sealing elements for fluid containment and contamination prevention.

Frequently Asked Questions

What is the difference between star points and star arms?

Star points typically refer to the tapered ends that engage with mating components, while star arms refer to the entire radial extension including the structural portion. In practice, the terms are often used interchangeably for the complete protruding element.

How do I determine the optimal number of arms for my application?

The number of arms depends on required indexing angle and duty cycle. More arms provide shorter dwell times and smoother motion but reduce torque capacity per arm. Common configurations: 4 arms (90° indexing), 6 arms (60°), 8 arms (45°).

What maintenance do star points/arms require?

Regular inspection for wear on engagement surfaces, lubrication of bearing surfaces (if applicable), and checking for proper alignment. Replacement is typically needed when wear exceeds 0.5mm or positioning accuracy degrades beyond specifications.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification
This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Request Manufacturing Insight for Star Points/Arms

Thank you. Your request has been sent. We'll respond within 1–3 business days.
Sorry, we couldn't send your message. Please try again, or email us at contact@cnfx.com.
Yoke Bracket
Get QuotesChat