Big discrepancy between drop-weight tension and pitch based tension meter

[tennischemist]

Hi, all

I have a Gamma drop weight (X-2) and I strung at 60 but in testing w/ an iPhone app (racquetTune), it read, based on pitch, a tension in the mid 40s.

Is my machine not properly calibrated or is it likely I lost that much tension due to some lack of skill in tying off the mains and crosses.

Another thing I'm curious about is placement of the frame holder along the machine's sliding X-axis, I'd never thought about this before but that would probably make a difference.

Any ideas?

 

[1HandedBackhand]

Which side of the weight are you setting your tension from? Should be the left side, I know it sounds silly but I have read where people get confused and use the right side of the weight.

 

[Chotobaka]

Have you ever checked the tension being pulled with a calibrator?

 

[SwankPeRFection]

I check my tension with that app and at most (if the string factor isn't right), I'm off by <5 lbs. Usually when I'm done I'm within 2-3lbs from what I set the machine to. I use an Alpha though. If this is your first time stringing or you've just started, it's possible your technique is causing you issues. Also, flying clamps aren't the best at holding tension properly when you string. It's very possible you're losing the 20lbs that way. That's a lot of lbs to be off by.

 

[Ramon]

Hi, all

I have a Gamma drop weight (X-2) and I strung at 60 but in testing w/ an iPhone app (racquetTune), it read, based on pitch, a tension in the mid 40s.

Is my machine not properly calibrated or is it likely I lost that much tension due to some lack of skill in tying off the mains and crosses.

Another thing I'm curious about is placement of the frame holder along the machine's sliding X-axis, I'd never thought about this before but that would probably make a difference.

Any ideas?

I have a calibrated Alpha drop-weight machine, and RacquetTune actually reads 6-7 pounds higher with a multifilament, probably because I pull for several seconds and tension of the mains increases when you weave the crosses.

Possible sources of tension loss include:
- Flying clamps (Are they tight enough? How much do the strings move because of the narrowness of the clamps?)
- Time and wear (How long has it been since you strung the racquet? How much have you played with it?)
- Type of string (poly can lose about 20-30% tension due to time and play).

If those factors are not significant, maybe it's the setup of the app. Did you input the correct racquet head size and string pattern? Did you use the correct string factor? Is this an unusual string that doesn't correlate to the default string factor because of composition, shape, or gauge consistency?