Stringing machines: drop-weight, crank or electronic, which one to choose?
A stringing machine does two things. It pulls each string to a set tension, and it holds the frame while you fill it. The first shows up on a spec sheet. The second barely shows at all, and yet it is what protects the racquet.
So before comparing models, it is worth knowing what each part of the machine actually does to the string and to the frame.
Three ways to tension a string
Drop-weight. A weight slides along a bar, and its position sets the tension. Gravity pulls the string, continuously: if the string stretches, the bar drops and keeps pulling. The tension is only right when the bar is level. It is the simplest, most compact and cheapest mechanism to maintain. It is accurate for anyone who watches the bar, and slow for everyone.
Lockout crank. You turn until it clicks, and the mechanism locks at the set tension. It is fast. But once locked, the machine stops pulling: a string that keeps stretching loses a little tension before it is clamped. Accuracy then comes from your hand, the same rhythm on every string.
Electronic. A motor pulls to the displayed value, adjustable to a tenth. Constant-pull models keep pulling as long as the string stretches, making up for what a lockout loses. It is the fastest and most consistent solution, and the most expensive to buy and to maintain. Some electronic machines are lockouts too: they stop once the tension is reached, like a crank.
The mounting matters more than the tensioner
During a string job, the frame takes the pull of thirty-five to forty strings, several hundred kilos in total. What keeps it from distorting is the way the machine holds it.
6-point mounting: two supports on the axis, at the head and the throat, and four side supports, two of which are posts inside the frame. The head keeps its width almost without thinking about it.
4-point mounting: head, throat and two side supports. It holds a frame well, as long as you tighten to contact without forcing a shape on it.
2-point mounting: only the head and the throat are held. Stringing order becomes the frame's only protection across its width: you alternate the mains, and never get more than three or four strings ahead on one side.
Whatever the system, the rule is the same: the supports stop the frame from moving, they do not shape it. Measure the outside width of the head before and after stringing. It is the one check that does not lie.
Fixed or flying clamps
Fixed clamps sit on a base that slides along the turntable. You move them from one string to the next without taking them off: faster, more precise, and the standard on mid-range and high-end machines.
Flying clamps hold two neighbouring strings together, with no base. They come with the simplest machines. They string just as well, provided they are set for the string of the day and placed tight against the frame; badly placed, they slip and let tension escape.
Either way, a clamp is set on an offcut of the string, not on the racquet: it must not slip when you pull hard, and it must not leave a flat spot on the string.
What the machine does not do
The tension on the display is not the tension in the string bed. Between the two come clamp position, stringing order, the knots, and how long you take to clamp. A high-end electronic machine in hurried hands strings less accurately than a drop-weight in steady ones.
That is why the method matters before the tool. The stringing assistant follows the job string by string and only shows the moves for your machine: electronic, crank or drop-weight, 2, 4 or 6-point mounting, fixed or flying clamps. It is in French, and the method is also written out in English.
How many string jobs before a machine pays off
Count a few hundred euros for an entry-level drop-weight or crank, and usually more than a thousand for a constant-pull electronic. On the other side, a string job at the workshop costs 12 €.
The sum is simple: a 300 € machine is twenty-five string jobs. That is one season for a player who breaks every two weeks, or for a family of three players; it is several years for someone who restrings twice a year. Then there is time: one to two hours for the first jobs, twenty to forty-five minutes with practice.
If you string often, string also costs less per metre: a 200 m reel covers sixteen string jobs from a single production batch.
Frequently asked questions
Drop-weight or crank to start with?
A drop-weight pulls continuously, like a constant-pull electronic, and forgives an uneven hand; all it asks for is patience. A crank is faster, but needs a steady rhythm to stay accurate. To learn, the consistency of a drop-weight is an advantage.
Buying a used machine: what to check?
The clamps first: worn jaws let the string slip or crush it. Then the turntable, which should have no play, and the supports, which should not mark the frame. Finally the tension: have it checked with a calibrator before the first job.
Should a machine be calibrated?
Yes, from time to time, and always after it has been moved. A stringing calibrator, placed between the tensioner and a fixed point, tells you whether the displayed value is what the machine really pulls. On a drop-weight, also check that the weight sits on the right mark: tension only reads with the bar level.
What if the job goes wrong?
Almost everything can be fixed, as long as nothing is released in a hurry: common stringing mistakes, and how to fix them.
Where can I learn with an instructor?
The stringing course at the workshop takes about three hours on a professional machine: one racquet strung from start to finish with the four-knot method, then follow-up with no time limit.
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