2015 Guide to Stringing Machines: Stand and Deliver

When it comes to efficiency and productivity, don’t forget the importance of your stringing machine’s ergonomics and comfort.

By Bob Patterson

The definition of “ergonomics” is: “The study of the relationship between workers and their environment, especially the equipment they use.” It’s not something most of us think about on a frequent basis, but it is a part of our daily lives.

Ergonomics touches everything we do. It is vital in automotive design, not only for driver comfort but also for safety. Having controls at easy reach of the driver and placed where their eyes never have to leave the road is crucial for safety and comfort. And we’ve all seen illustrations about how our computer monitors are supposed to be at eye level, our keyboard at optimum position and our backs straight to relieve stress and fatigue — points driven home after using your laptop in the easy chair and ending up with a stiff neck. We also hear of ergonomics in the workplace with jobs that require repetitive motions or prolonged time in one position.

So, what about the ergonomics of your stringing machine workstation? Ever given any thought as to why the tension button is placed there, or the tool tray there? Why is the clamp lever shaped like that? Well, the people designing the machine thought about it.

In speaking with several companies, it seems that ergonomics play a vital role in how stringing machines operate. “We view ergonomics for a stringing machine being the next most important aspect just after quality of design and workmanship,” says Tom Parry of Pacific. “You need to have a quality, well-built machine to start with, then a machine that is designed to be as user-friendly as possible.”

Ron Carr, Gamma’s v.p. of research and development, says, “In general, ergonomics factors do influence the design of every major component of the machine in some way. They can be related to any number of physical or cognitive ergonomic factors such as physical movements, ease of use, functionality or intuitive use.”

Parry breaks down the ergonomics into two major categories: physical and visual. Both are important to the technician not only for comfort, but also for long-term health.

PHYSICAL ERGONOMICS

When you say the words “stringing machine” and “ergonomics,” most stringers first think of machine height. If you share a machine with others, adjusting the machine to suit the varying heights of the technicians is paramount to comfort. Of course, there is much more to your comfort than simply the machine height but that is a great place to start.

Working Height

Most technicians agree that the most comfortable working position is having the frame at elbow level. With the frame mounted in the machine and the technician standing upright, the frame should allow the technician to place his or her hands on the string bed with the elbows bent at 45 degrees.

In a quick, unscientific survey, this was the position of choice by most technicians we talked to, although some preferred a slight adjustment of an inch or two up or down.

Ron Rocchi of Wilson says that in the development of the Baiardo stringing machine, they found the best working height was different for main- and cross-string installation. “We found that installing main strings consisted of long, fast pulls, while cross-string installation required more detail-type work.” For this reason, when using the Baiardo in the automatic mode, the machine raises slightly for cross installation. The turntable also tilts, exposing the grommets to more light, making the holes easier to see and placing the work closer for the detail of weaving crosses.

Another consideration in this aspect is how the height adjustment is accomplished. Some machines are raised and lowered manually, while others have an onboard motor to elevate and lower the machine with the push of a button. On manual operations, you should consider the overall weight of the machine since heavier machines may require two people to lift it while another loosens and tightens the holding mechanism.

Ultimately, you want a work height that allows for a comfortable stance and doesn’t put undue strain on the technician.

Working Reach

What reach requirements are needed in the operation of the machine? Can the tension be activated easily? On a manual machine this is fairly obvious, but it can also be key in electronic machines as well. Where are the tool trays? Are they easy to reach and designed to make grabbing your tools easy?

Mark Gonzalez of Alpha says that when they were designing their latest machine, the Ghost, stringing tool access was high on the priority list. “We have two tool trays that are imbedded in the mounting table and two more on the tension head module.” This gives the technician plenty of room for tools and options for where to store them within easy reach.

Many electronic machines have the option of tension head activation via a foot pedal. This certainly alleviates the need to reach for the button. Grant Morgan, an MRT in Memphis, finds that activating the tension head with the button is easy since most are located adjacent to the pulling clamp, but he uses the foot pedal to release, making the overall operation more efficient and increasing his work speed.

The new Gamma 9900Els model features the “Auto-Start Gripper.” According to Carr, “The tensioner switch is built into the gripper and is activated when the string is inserted between the gripper jaws and pulled against them. This eliminates the extra hand motion needed to press or touch a separate switch.”

Frame Mounting

This seems like a straightforward task, but ergonomics play a key role in how easily the frame can be mounted securely. How many movements does it take? How much force must be applied? Obviously, the easier and quicker the mounting system, the less strain and stress on the technician.

Clamp Operation and Adjustment

A lot of ergonomic design goes into clamps, from the curvature of the handles to the amount of force required to operate them. Again, pretty straightforward, but the simpler this task is, the better it will be for the technician, especially since this is the most repetitive motion in the stringing process.

Carr says a lot of ergonomic design goes into the Gamma clamp, not only in the shape, but also the function. “Rollers and bearings are incorporated at each pivot point to reduce the amount of effort needed to close and open the clamp and provide a positive indication when the cam linkage travels over center and clamps the string.”

Also, the adjustment of the clamps should be considered. Again it boils down to ease. Is it simply a turn of a knob or does it require tools and more effort?

Tension Setting

These days this is usually simply turning a dial or pushing buttons, but there still are considerations. Where is the control panel located? Is it easy to reach and see? Is it a simple task or does it require multiple screens and button pushes to make a simple adjustment?

Table Lock

Most professional tables have this feature, but how easy is it to operate and to reach? Like the frame mounting, you need to consider location and amount of strength required to activate and release it.

VISUAL ERGONOMICS

As we age, the eyes dim a bit, so the light in your workspace is an important factor. But the design of the machine itself also must be considered.

The Turntable

During the stringing process, the turntable is a consistent point of focus. Parry says Pacific adheres to a “keep it simple” principle. “If there are too many distracting colors, or too shiny of a surface, or even too dark of a surface, it is not as easy to see the ‘weave’ and can quickly add to eye strain.”

Dial or Input Screen

It’s imperative that the numbers be easy to read. On a manual machine, you shouldn’t have to get out the magnifying glass because the numbers are so tiny or the contrast between the background and the dial make it hard to see.

The same is true for electronic machines. The screen should be bright and easy to read. Setting tension or other settings should be simple and straightforward. Placement of the screen is also important. Technicians will often look at the screen during the stringing process, even if no more input is required. So the screen needs to be easily seen and readable from the operating position.

When you are shopping for a new machine, along with all the bells and whistles on your wish list, consider the ergonomics. Doing so will ensure that your new machine will serve you well, and you’ll enjoy working with it for many years.

See all articles by Bob Patterson

About the Author

Bob Patterson , the founder of the RacquetMAXX customization service, is a Master Racquet Technician with more than 20 years of experience. He was RSI's Stringer of the Year in 2005. He is Executive Director for the U.S. Racquet Stringers Association.