Can Electromagnets Achieve High Holding Force with 30cm Separation?

[boileroo]

Hi,

I am investigating the possibility of using 2 oppositely polarised electromagnetics to locate 2 moving bodies into the correct position as they move towards each other and would appreciate some thoughts on the feasibility of the solution and ways it might be improved.

I am proposing using magnets such as these: http://www.eclipsemagnetics.com/media/wysiwyg/datasheets/magnet_materials_and_assemblies/energise_hold_100mm_datasheet.pdf

They seem to have a high holding force of ~350kg (side question: if I have 2 opposing magnets, will the holding force be ~700kg?), but the force very quickly drops off as distance increases. Ideally, I would like the magnets to be drawn together when they are within approx. 30cm of each other. Is it feasible to expect electromagnets to achieve this (either these magnets or another alternative)?Building my own magnets is not an option; they must be available off the shelf. I know that electromagnets have excellent holding capability when there is no air gap, so I am sceptical whether or not this is possible.

One of my concerns originally was the power consumption of such powerful magnets, yet these magnets only draw ~1.8A. Is this expected? I was expecting a magnet capable of holding 350kg would draw vastly more current than this, but that could be my lack of understanding talking...

Many thanks for the help

 

[JBA]

The magnetic pull reduces as a factor of the square of the separation; so the attractive force of these magnets will be almost undetectable with 300 mm separation.