View Full Version : Tension spring good for high tension out on low tension
11-17-2006, 10:06 PM
I was just testing the tension on a used machine I just bought, a Tenex/Gamma 6000. I find that on tensions 60-70 lbs, the calibrator shows the tension is accurate. But if I test for lower tensions, 30-40 lbs, it's out by as much as 5 lbs.
What is this indicating about the tension spring? Is this anything to be concerned about? I'm mainly string tennis racquets, so it will be in the high 50's to low 70 lbs, so does that mean I'll just have to compensate if I'm stringing racquets that require lower tension?
11-19-2006, 03:00 PM
I've run into the same thing with a rarely used 6000. The release doesn't feel crisp at all and the tension needs to be checked after each frame. My main Gamma 4000 machine has well over 4500 stringing since I purchase it new in 1987.:confused:
11-20-2006, 08:25 AM
You need to adjust the spring tension curve and the machine will be calibrated at low & high tensions. When calibrating you can change the offset and/or the tension curve. The offset is if the tension is off by 3 lbs @ 30 & 70 then you change change it by 3 lbs and it is fixed (you've been doing the offset adjustment-brake lever hook). the tension curve can be adjusted so it is accurate at one point but the further you are from that point the greater the tension difference. You can correct the curve to be accurate. There are a couple of adjustments and it will take a lot of trial & error. try the following adjustments one at a time, if it doesn't correct it then move the part back to its original position.
do all these steps and mark the original positions and check the tension at 30 & 70lbs. you'll have to be using the offset adjustment at the same time.
rotate the spring by 90 degrees, check @ all 3 positions.
on the arm that goes from the gripper to the tension spring: you can move the spring lower on the same arm to increase it at higher tensions, it doesn't seem to affect the lower tensions that much. I would try this and if your machine is still on @ 60 lbs and 5 lbs high at 30 lbs, I would adjust it to be 5 lbs higher at 60 lbs (pulling 65 lbs), then adjust the offset by 5 lbs and you would be accurate at 30 & 70 lbs and then everything in-between.
on the same arm: adjust the cam that is 1/2 down the arm. at least make sure there is enough pressure on it when the tensioner is set to 0 lbs that it hold the spring in. (make sure the spring is seated properly).if you can get the tensioner adjusted properly you will be well on your way to figuring them out, then you will just need to master the brake adjustment.
11-20-2006, 08:56 AM
Thank you. I'll try that the next time I'm at the club. Since it is an outdoor club in Philly, it may be awhile.:)
11-20-2006, 11:45 PM
Thanks so much for the help Bret. It makes it so much easier to have found someone with so much info on the stringer I bought.
Now that you've offered a teaser about the brake adjustment, can you provide more info as to what this is and how this improvement will help so my machine will be as accurate as possible?
11-21-2006, 08:15 AM
the brake adjustment won't affect the accuracy of your machine. it is the only other hard adjustment to master with the spring tensioners. if you are not having trouble with the tensioner moving after the brake lever is released, I wouldn't touch.
For somebody hopefully using the search feature in the future: here is some more information about how the brake works and common problems: disc brake is dirty (clean with alcohol or paint thinner or solvent-be careful around plastic), brake lever weld broken, spring is stretched or broken, brake pad is worn at an angle, brake pad fell out and brake pad doesn't make maximum contact (at a slight angle) with the disc brake and tensioner creeps forward after the brake lever is released.
to do a brake adjustment on a 6000 (other machines are very similar) you need a 6mm allen wrench for the front screw and a 10mm socket or wrench for the locking bolt on the back above the tension spring. You need to work the 2 screws simultaneously, start off by loosen the 10mm bolt a 1/2 a turn or less, just enough so the 6mm bolt can rotate with the allen wrench. if needed you can remove the cover. With the cover removed and you standing with the disc brake & crank facing you, front to back you will see the screw in the middle, brake lever, a washer, brake pad, disc brake, brake pad & tensioner frame. The major part of getting the brake adjustment correct is to get the 6mm allen bolt, in the center, to butt against (no gap) the tensioner frame and tighten up the 10mm set screw in the back. when the brake pad is in the correct position it needs to be parallel with the disc brake for maximum gripping. Also, the 2 screws in the middle top of the pad adjusts the angle of the brake pad by moving the nuts in or out. It also affects the travel on the brake lever. I only need to adjust this about 10% of the time.
you can allow look at http://www.gammasports.com (http://www.gammasports.com/) and "Product Manuals" and there are pictures and different explanations in the machine manuals.
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