A piece of large diameter rope, a sharpie, and a box cutter will be a lot more accurate than a tape measure. Then just glue the ends of the rope together if you wish, and head for the parts store!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!