From: "Ted Channel" tchannel@............

Date: Sun, 27 Dec 2009 06:59:50 -0700

Hi Folks, I have downloaded Bob McClure's great program SpringCalc.exe. = I have put in some numbers and see it calculates very long periods = under certain conditions, periods of >20. My question is can long periods like these really be achieved? I have = build several models and some working sensors using this approach, but I = have never gotten more than about 3x the springs natural frequency. A = spring of .5 second, just hanging vertically, resulted in a sensor of = 1.5 seconds. I guess the AS1 is another example. The design of the = AS1 is widely used and am I correct that it is operating at about 1.5 = seconds? In theory, is this shape, capable >10 seconds? I hope to use Bob's program to construct another vertical, but I am = confused, about my results. I know there are methods for extending = the period, but here I am just asking about the physical results of = using a spring-supported pendulum constrained to move in a vertical = plane. Perhaps these calculated long periods would only be possible = under the best of conditions, where all factors were perfect. I seem = to get a period of around x3 that of the spring hanging vertical with = a mass. I have tried many different springs and the result were very = similar in achieving only x3.Hi Folks, I have downloaded Bob = McClure's=20 great program SpringCalc.exe. I have put in some = numbers and=20 see it calculates very long periods under certain conditions, periods of = >20.My question is can long periods like = these really=20 be achieved? I have build several models and some = working=20 sensors using this approach, but I have never gotten more than about 3x = the=20 springs natural frequency. A spring of .5 second, just = hanging=20 vertically, resulted in a sensor of 1.5 seconds. I guess the = AS1 is=20 another example. The design of the AS1 is widely used and am = I=20 correct that it is operating at about 1.5 seconds? In = theory, is=20 this shape, capable >10 seconds?I hope to use Bob's program to = construct another=20 vertical, but I am confused, about my results. I know = there=20 are methods for extending the period, but here I am just asking about = the=20 physical results of usingPerhaps these calculated long periods would only be = possible under=20 the best of conditions, where all factors were = perfect. I seem=20 to get a period of around x3 that of the spring hanging = vertical=20 with a mass. I have tried many different springs and = the=20 result were very similar in achieving only x3.a = spring-supported=20 pendulum constrained to move in a vertical plane. =20Thanks, Ted