Magnetic wheel by steel shielding

[vineet_kiran]

Video at :
https://youtu.be/ExygPXDzLow

By moving a steel plate as a shield between two repelling stack of magnets, one on wheel and another fixed to the table, the
wheel can be made to rotate continuously.
If a roller ball is used between the magnet and the shield, the shield can be moved easily over the surface of magnet because the magnetic field is almost uniform in parallel plane.

[Paul-R]

The issue with this type of device is often that it takes a small but important amount of energy to move the shielding in and out of position.

[norman6538]

The principle  appears to be blocking magnetic field but it is really shunting/diverting that field away so there
is no repel force and the rotor slips past the repelling magnet.

Yes the principle works but it takes work to move the metal and when I did this it was as much work as the output rotation. Remember rotation is easy.

But I wish you the best. I will watch. Norman

[vineet_kiran]

The principle  appears to be blocking magnetic field but it is really shunting/diverting that field away so there
is no repel force and the rotor slips past the repelling magnet.

Yes the principle works but it takes work to move the metal and when I did this it was as much work as the output rotation. Remember rotation is easy.

But I wish you the best. I will watch. Norman

I have posted reply on youtube :
'Thanks for the comment. What if magnet stacks are placed horizontally and the steel shield is moved horizontally? In that case energy required to move the shield up is removed. If we use magnets which are magnetized uniformly from one end to the other (for example surface of a ring magnet which is axially magnetized) it may not generate opposing Eddie currents because emf and current are produced only when there is 'rate of change of flux'. Any thoughts?'         

[skywatcher]

In any case the energy to rotate the wheel comes from your hand. Magnetic fields can not be shielded. Your 'shield' only distorts the magnetic field, and when you move it you have to work against the magnetic field which requires energy. The only way to really shield a magnetic field would require a non-magnetic shielding material, but nobody has found such material yet.

Please keep in mind that simply rotating a wheel without any load requires very little energy so you might not have the feeling to do mechanical work with your hand.