View Full Version : Fun stuff

01-06-2009, 03:09 AM
This site has everything I ever lusted after except one :)

Vortex tubes, gyros, Tesla turbines, planes, rockets, ornithopters, Stirling engines, Halbach arrays, and more. They have a number of YouTube videos of some of their toys. Too bad they're on the wrong side of the world...


01-06-2009, 03:29 AM
Awsome! I love "physics" toys. I still have that little gyroscope I made a year or two ago. I still love playing with it! :)

Ian B
01-06-2009, 05:54 AM
Talking of gyroscopes, anyone know how one of these works: http://www.powerballs.com/works.php?m=Works

Something to do with 'fighting' the precession of a gyroscope, and does that cause the rotor to spin faster? They certainly work.

Might also be a handy source of an RPM indicator if anyone needs one.


A.K. Boomer
01-06-2009, 10:07 AM
Cool site, Powerballs are amazing and they work just like you state --- its best described as staying a step ahead (or behind depending how you look at it) of the precession and has allot to due with timing --- you simply "roll" your wrist to get it started (after you get good - beginers use a pull cord) and as the gyro builds momentum it then allows you to put more torque to it, this snowballs and you can wind them up well past 15,000 RPM's, they have a little built in magnet and an electronic pick-up coil and digital readout..

Inner workings consist of a basic gyro with two opposing axis shafts to spin on --- however - thats where the similarities end -- the axis bearings are tiny little pieces of sintered bronze, they are round I.D. and square O.D. The square O.D. is allowed to slide in the external casing/housing as there is a groove cut all the way around it for this purpose, The bearings fit perfectly on the I.D. but have much clearance and fit loose in the O.D./groove but they are spring loaded ever so slightly --- this enables the gyro to coast without any O.D. groove action while the axis is allowed to spin freely --- Last but not least --- the axis shafts extend further into the case/housing and into a finer cut groove -- it has less clearance then what is allowed for the square groove O.D. --- This is what accelerates the powerball, when you cock the powerball and start Rolling your wrist you bye-pass the spring loaded square/O.D. mechanism and get the axises of the gyro involved directly with the outer casing --- and with the position you hold the powerball it loads one axis on one side of the outer casing while the other takes the opposing side, this is what makes this toy so intriguing --- now you have a means of a direct contact link and drive ratio with the gyro, (maybe something like 25 or 50:1) as long as strong contact is resumed (enough to bye-pass the coast springs) you will be able to keep accelerating it --- try to stop it on a dime and the axis ends stay loaded in the housing groves and the force tries to rip your wrist off as the unit transforms from generator to motor.
If you get one the secret to making it last is to always make an effort to keep it engaged --- it is in the mild half ass engagement where its seeking between a free coast or the load springs allowing the axis ends to come in contact with the housing that the ends will wear notches into the housing and then the thing is very rough and will never get up to speed, Oh yeah -- dont take it to the beach either:o they dont like sand...

01-06-2009, 01:34 PM
Vortex tubes for industrial use can be obtained from ITW Vortec http://www.itwvortec.com/vortex_tubes.php

We used some of their air amplifiers in cooling system tests on automated test equipment.