In article ,
Rich Grise wrote:

robobass wrote:

Enough with the safety tips already! The thing only hangs two feet off
the floor anyway so the toddler can swing it and watch the new baby.
The screen door spring sounds like a possibility. Any engineers out
there who can quote me some more precise numbers, like load/deflection/
rate etc? I'm looking through McMaster and getting a clue, but still
pretty dim on this. They do sell the exact thing I want here where I
live in Germany, but they can cost upwards of $100 new. I ain't one of
those types who pays a hundred bucks for a three dollar spring.

Speaking of springs, I remember seeing a physics demonstration of a thing
hanging on a spring, and the trick was they picked the spring such that
the period of the rotational moment was the same as the period of the
spring moment, (twirling vs. bobbing); and the motion traded off from
twirling to bobbing and back and so on. I have no idea how to adjust
either, other than changing the rotational inertia of the basket with
weights. ;-)

Wilberforce Pendulum

http://en.wikipedia.org/wiki/Wilberforce_pendulum

This will lead to a very confused child.

Joe Gwinn