Ensuring String Tension Stability: Strategies for Crank Lockout Stringing Machines

String tension loss is a common concern when stringing squash and tennis rackets with crank lock out type machines. Recall from the different types of stringing machines article that the key advantage of constant pull machines is that strings remain in the tension that was set by the stringer when being clamped. In crank lock out type machines, it is common to see strings lose a pound or two of tension due to relaxation after the lock out.

String tension loss crank machine
Crank lock out stringing machine

Experienced stringers understand this, and have come up with ways to minimize the loss of tension and get just as accurate as the constant-pull machines. This is what this article is about.

Pre-stretching for Tension Stability

  • Prestretching involves elongating strings before tensioning and locking them into the racket frame. This process minimizes the initial tension loss that occurs as strings settle. Read this post about prestretching.
  • Prestretching with Crank Lockout Machines: For crank lockout machines, prestretching is even more essential. It helps the strings adapt to tension and reduces the chances of rapid tension loss post-stringing.

Crank and Lock Multiple Times

  • The Cranking Technique: After mounting the racket, start by cranking and locking out the strings multiple times at the desired tension. This process helps the strings settle, reducing tension loss after stringing is complete.
  • Tension Redistribution: Cranking and locking out multiple times ensures that tension is evenly distributed across the strings, enhancing tension stability. You will notice that when a string is clamped (assuming you are using the fixed kind) there will be some deviation or movement of the clamp with the string is released from the crank/tension head. This deviation would decrease with every repeated crank and lock out.
  • Yes this repetitive cranking would result in an overall longer stringing time. It is however worth it if you are aiming for accurate tension. As an alternative which may be faster, you could try the “slow crank method” discussed next.

The Slow Crank Technique

  • Slow and Steady: When using a crank lockout machine, cranking slowly allows the string to gradually relax and stretch as tension is applied.
  • Enhanced Elasticity: This slow process imitates natural string behavior, helping the strings adapt to the desired tension more effectively and reducing the chances of sudden tension loss. As compared to the repetitive cranking method, you just need one good controlled crank. This would save some time stringing time and improve the accuracy of the stringing job.

By incorporating these strategies into your stringing process, you can minimize tension loss and ensure that a squash or tennis racket remains consistent and reliable over time. From prestretching for foundational stability to cranking and locking techniques that distribute tension evenly, and the patient approach of slow cranking, these methods collectively empower you to combat tension loss and elevate your racket’s performance.

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