Tennis Racquet Stringer

     Being an avid tennis player, one may delve into the realm of racquet stringing. In doing so there are two main types of stringers, an electronic one and a drop weight one. The trade-off between the two is that the electronic one strings a racquet in about half the time as a drop weight, but at more than twice the cost to purchase. This project was motivated by a need for a device that would string a racquet using a drop weight system at a faster rate than a conventional drop weight stringer so as to compete with an electronic version and still be low cost. 

 

For a function statement: 

A device is needed to apply a desired tension on a string in order to string a racquet in less time than a conventional drop weight stringer.

 

This device must:

• Provide a tension on the string at a range of 30-90lbs.

• Have a weight that is adjustable to provide a moment between 60-180 ft-lbs about the axis of rotation.

• Have a string locking mechanism that doesn’t allow slip by applying at least 78lbs of force for clamping.  

• Not tip at the max moment of 180 ft-lbs.

• Have a support arm that does not deflect greater than 0.50in.

• Have a base with 360˚ rotation.

• Ensure the string has no greater than +/-8.5˚ deflection from the grommet hole to the string locking mechanism so as to keep the tension within +/-1lb.

• Have the string locking mechanisms joined to have synchronized ratcheting.

• Provide the ability for the string locking mechanisms to adjust horizontally at 0.50in increments to a max distance of 3in on either side.

• Provide ratcheting at an arc distance no greater than 0.25in per tooth.

• Have a ratcheting gear that can withstand a max of 90lb of shear force.

• Have a pressure arm beam deflection less than 1.00in.

 

For this device to be successful it must:

• String a racquet at the proper tension within the specified requirements.

• Reduce the time to string a racquet compared to the conventional way.