Opposing magnets, how to minimize off axis force?
Opposing magnets, how to minimize off axis force?
(OP)
We have a device that uses opposing magnets to transfer force from an object to a sensor. The object is attached to a ring magnet. The ring magnet is kept in its vertical axis through a guide rod. The other magnet, a disc magnet, is attached to a sensor.
The problem is: the off-axis force or side load force on the ring magnet is causing stiction between the guide rod and the ring magnet.
Any ideas on how to minimize this force? Can we modify the sizes of the magnets, however, if the ring magnet ID is made too large, it will attract the disc magnet rather than oppose it.
Thanks in advance,
Greg
RE: Opposing magnets, how to minimize off axis force?
RE: Opposing magnets, how to minimize off axis force?
-Greg
RE: Opposing magnets, how to minimize off axis force?
Can you make the guide rod (and the ID of the ring magnet) have less friction by using low friction coatings?
RE: Opposing magnets, how to minimize off axis force?
You want repulsion, axial centering, and resistance to tipping.
Earnshaw's theorem says it can't be done (except perhaps a few loopholes.)
How about mechanical means to bevel/smooth the i.d. of the ring magnet so it doesn't bind, or lubricate those surfaces.
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RE: Opposing magnets, how to minimize off axis force?
-Greg
RE: Opposing magnets, how to minimize off axis force?
You could use plastics for the bearings, but when they get nicked they tend to stick.
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