Magnetic Damping to Minimise LF Vibration
Magnetic Damping to Minimise LF Vibration
(OP)
I am currently prototyping a new device which is a software controlled electromechanical unit - the central part of which is a counterbalanced radial arm which rotates about a central shaft alternately clockwise and anti-clockwise through 180 degrees taking about 2.5 seconds to move from 0 to 180. I have found that this arm tends to vibrate at a low frequency (possibly 5-10Hz). This looks like a resonant-frequency effect. As luck would have it, there is also a disc of Aluminium (Aluminum?)about 180mm diameter, 3mm thick attached to the shaft. Would it be possible to place 2 powerful magnets (NdFeB?) diametrically opposed such that the disc travels through the gap to dampen this vibration and, if I'm on the right track, what order of magnet size and gap would be a good starting point for testing this? BTW I'm a Programmer and Computer Support Manager so keep it simple!
Thanks,
Dave
Thanks,
Dave





RE: Magnetic Damping to Minimise LF Vibration
RE: Magnetic Damping to Minimise LF Vibration
Thanks again,
Dave
RE: Magnetic Damping to Minimise LF Vibration
don't believe magnets will help at such low velocities (frequencies).
you need to look at the resonant frequencies of your rotating arm (as a beam). you may need to stiffen it.
the bearing problems can be sorted out, but you may need to control the rate of acceleration of your motor to avoid exciting the criticals of your structure.
RE: Magnetic Damping to Minimise LF Vibration
The motor speed is controlled by the software which starts the motor at about half-power then increases to three-quarters then full power (and the inverse for stopping). If necessary I can put in more steps to minimise the excitation but at the moment it looks fairly smooth.