How to find the right Mechanical Power Springs AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in Mechanical Power Springs
- Torque and turns
- Specify the torque you need across the full working range and the number of turns you need, with margin before the spring is fully wound. A power spring's torque varies with how far it is wound. Working near either end of its range is unreliable.
- Cased vs uncased
- Choose a cased (housed) spring unless your design provides its own retaining housing. Uncased power springs store a lot of energy and can uncoil violently when released.
- Arbor and housing fit
- Match the inner-end attachment to your arbor diameter and drive feature. The housing inner diameter must hold the spring's free outer diameter. A mismatched arbor slips or concentrates stress at the inner end, the most common failure point.
- Winding direction
- Confirm clockwise or counterclockwise winding from the drive end before ordering. A spring wound the wrong way cannot be mounted to drive correctly.
- Material and cycle life
- Use carbon spring steel for dry, indoor, moderate-cycle uses. Use stainless for corrosion or higher-cycle designs. Ask for the cycle rating for your duty. Fatigue life and corrosion resistance set the service life in retractors and rewind mechanisms.
Brands that matter
- Vulcan Spring: Makes power, clock and constant force springs and publishes sizing guidance.
- John Evans' Sons: A long-established maker of power and spiral springs, including custom designs.
- Lee Spring: A general stock-spring source worth checking for standard spiral torsion parts.
What to avoid
- Removing or replacing an uncased power spring without a retaining ring or proper winder.
- Generic replacement springs with no torque or turns data for clocks or retractors.
- Running the spring fully wound against its stop in every cycle.
- Lubricants that attract grit in open, uncased assemblies.
Questions
What is the difference between a power spring and a spiral torsion spring?
A power spring has many tightly wound turns in a housing, gives many turns of output and suits retractors and rewinds. A spiral torsion spring has open, spaced coils, gives less than a few turns of rotation and suits return and counterbalance uses.
Can I swap a constant force spring for a power spring?
Not directly. A power spring stores torque on an arbor for rotary rewind. A constant force spring gives near-steady linear force. Choose by whether your output is rotary or linear.