Engineering · FEA study
Our engineers used Finite Element Analysis to compare Pro Stringer’s direct-to-frame tensioning with conventional external anchor systems, modelling how force travels through a racquet under load.
The finding: balanced, symmetrical loading spreads stress across the frame instead of concentrating it. Here is what the model shows.
Why it matters
Every time you string a racquet, significant forces are applied to its frame. Uneven or concentrated forces can deform the frame during stringing and contribute to structural fatigue over repeated string jobs.
During development, our engineers used Finite Element Analysis (FEA) to understand how those forces and stresses are distributed. The analysis helped inform a different approach to tensioning.
Instead of pulling against an external anchor, Pro Stringer applies tension directly against the racquet frame. Balanced opposing forces distribute the load more evenly, helping minimise unnecessary stress while delivering precise, consistent tension.
The force on your frame
Explore how the system and mounting configuration change the way force is distributed across the racquet frame.
Illustrative force distribution; colours do not represent measured stress values.
What the comparison illustrates
With 2-point mounting, the Pro Stringer comparison shows a more evenly distributed load and a smaller peak stress zone.
Two mounting points support the top and bottom of the frame.
The mechanism
The difference is the path the force takes through the frame, and the distance from the frame to the tension head.
Tension pulls the string directly against the racquet frame, creating balanced, compressive forces. The smart tension sensor adds two points of support where the tension head meets the frame.
The frame is loaded against itself, symmetrically.
A conventional machine pulls from an external anchor point. The tension head sits farther from where the string exits the frame, creating a one-sided pull on the racquet.
The FEA comparison shows a concentrated stress zone.
Diagrams simplify the mechanism and are not to scale. The two sensor contact points are additional to the selected mounting configuration.
The string path
On a conventional machine, the tension head sits away from the frame. The length of string in that gap is tensioned on the first pull. When that same segment is fed back through the racquet for the next run, it is tensioned again.
Pro Stringer grips and tensions the string right where it exits the frame. This short pull distance avoids drawing out the long external segment that would then be fed back in and pulled again.
“Twice” refers to the external segment being tensioned again on the next run, rather than two pulls on the same installed string.
The highlighted segment returns to the string bed and is tensioned a second time.
One pull for each string, without the long drawback shown above.
String paths are simplified to show the sequence; not to scale.
What the model found
Direct opposing forces reduce peak stress in the FEA comparison with conventional external-anchor tensioning.
Balanced compressive forces distribute the load across the frame instead of concentrating it in one area.
Both 2-point and 6-point configurations spread the load. The smart tension sensor adds two further contact points where the tension head meets the frame.
Reducing localised stress concentrations helps protect the frame from deformation and repeated loading.
Gripping at the frame exit avoids the long external string segment that a conventional machine tensions, feeds back into the racquet, and tensions again on the next run.
Engineered to be kinder to your racquet and truer to your tension.
