How long is the rubber band without slingshot?

Frameless slingshot, the length of the rubber band is to measure the stretch ratio of the rubber band, then put a proper bow opening posture, measure the length, and then divide it by the stretch ratio of the rubber band, and add 1CM to tie the head, which is the length of the frameless slingshot and rubber band.

Length of rubber band to be cut = self-stretching distance? Divide by? 90% of the stretch ratio of rubber band, multiplied by two, plus eight.

For example, my stretching distance is 1 18, and the ultimate stretching of rubber band is 1 to 7.4, so I take 1 to 6.5 for 90% stretching. Because the ultimate stretch hurts the rubber band, I take 90%, and my stretching distance is 1 18 divided by 6.5.

reference data

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