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D Wilson
01-14-2007, 03:07 PM
I have a 5800 Gamma stringer and I was wondering how does the pre stretch button work.

jj300
01-14-2007, 08:14 PM
assuming you select a percentage, ex 5%. The machine will pull 5% over your tension, for example if you set your tension at 60lbs, the machine will pull 60lbs +5% and it will then drop down to 60lbs again, and let you know that the pull is done. many stringers avoid the machine prestretch because it is not considered a "true" prestretch. A true prestretch involves stretching the entire string length at once so the prestretch is even across the entire length of the string. A machine prestretch works on every pull and therefore some lenghts of string will be prestretched twice.

Gamma Tech
01-15-2007, 05:49 AM
assuming you select a percentage, ex 5%. The machine will pull 5% over your tension, for example if you set your tension at 60lbs, the machine will pull 60lbs +5% and it will then drop down to 60lbs again, and let you know that the pull is done.

just to clarify this point (and D Wilson you can verify with a scrap piece of string) the machine would pull to 63lbs in this cases and then it completely releases the tension and re-pulls to 60lbs.

bret