Recently I bought a beautifully machined steel top and a small glass surface for spinning the top. I find it pretty intriguing. As a kid I would spin a top and if it kept spinning for more than 15 seconds it was a good spin. This little top routinely will spin for over two minutes, and so far my best time is just short of 5 minutes, which I think is incredible. I don't understand the physics involved, but I have noticed that if in the spin I impart a wobble to the top, often that wobble will immediately start to increase in angle and the top will fall over shortly afterward and come to a stop. But sometimes, the wobble reduces in angle, and then completely get eliminated and the top appears to not be moving as it stands on its tip, rapidly spinning. It seems that the degree of tilt to the top initially is what determines if it will straighten itself out or increase and stop the spin totally. I find it pretty fascinating. Pricing of one of these tops seems to start at about the amount I paid, $15 but some go for as much as $75. Well worth the $15 for the amusement factor.
Spinning a quality top
- Thread starter vito
- Start date
Not real complicated. As long as the momentum can overcome the friction it will spin. However, as some point as it slows it his it's critical speed. When that happens it becomes out of balance wobbles and falls over. The better balanced, smother the point and surface it's spinning on and the initial speed of rotation determine how long it will spin. Somewhere I once saw a formula for determining how long a top would spin. The formula gave you the number of rotations.
OP
I’m trying to get the knack of spinning the top with as little wobble as I can. Right now it seems more like random luck when I get a really good spin that keeps the top spinning for 3, 4 or even that one time that I had it go almost 5 minutes. I find this top is a nice diversion to play with at my desk.
Phoenix too
Blackhawk
For a detailed explanation: http://www.physics.usyd.edu.au/~cross/SPINNING%20TOPS.htm
