View Full Version : Calibrating a Silent Partner Swing

09-14-2006, 09:23 PM
I bought a silent partner swing drop weight stringing machine a year ago. Does anyone know how to calibrate the drop weight machine. I have this calibrator (http://sptennis.com/images/Calibrator.jpg). Any help would be greatly appreciated.

SW Stringer
09-15-2006, 06:16 AM
Drop weight machines don't need to be calibrated since the tensioning mechanism is a simple lever arm machine and depends on gravity which doesn't change unless you relocate geographically. So the string bed stiffness you get with the machine set to 55 pounds today will be the same string bed stiffness you get with the machine set to 55 pounds ten years from now. This assumes the same technique is used both times. With spring lockout machines and electronic machines , the parts that provide the reference tension (springs, load cells, electronics) can go out of adjustment with time so you must periodically check the tension heads pull against a calibrator to be absolutely sure nothing has changed. Of course the calibrator itself must be "calibrated" and it too will drift with time and need to be "re-calibrated".

I believe what you're asking is "does the 55 pound setting on my machine actually pull with 55 pounds of force?" To check that calibrate your calibrator with 55 pounds of certified weights and then hook it up to your machine and see. Whether or not the 55 pound setting actually pulls with 55 pounds or 54 or 53 or 56 doesn't matter, it will pull with whatever constantly from the day you got it and for the rest of your life.

Hope that helps.

09-15-2006, 07:11 AM
Something to watch for with the Swing (and probably other dropweights) if you remove the weight rod for storage between uses. The end of the rod has a notch cut into it, which you line up with the hex screw on the drum when you put the rod on. Be careful to line them up correctly -- if you just insert the rod all the way in, the rod goes a little too deeply into the hole and the hex screw doesn't catch in the notch. The stringer will work OK like this, but the weight will be 1/4 inch closer to the drum than it should, which corresponds to about a pound on the scale built into the rod. Not a great error, but it's there. To do it correctly, when you insert the weight rod into the drum, you have to back it out a little bit and find the notch with the hex screw before you tighten it down.

09-15-2006, 08:43 AM
I have a question. Do I have to detach the rod and weight when I am not using the machine?

09-15-2006, 09:24 AM
No. It just takes up less room. I only string a racquet every few weeks, so I take the rod off and put the whole thing back in the box it came in, and store it in my garage. No reason to take it apart if you have the room to leave it set up somewhere.