If a magnet could switch, could it attract and repel?

  • #1

Main Question or Discussion Point

attract.png
apart.png


Hello the first image with the letters going ABCD is picture #1 and then BACD is picture #2 for references.
Tools:
- Normal magnet. Nothing special about them.
- And we will say they have some type of system where they do not move sideways. Only up and down and have a difference of 5 cm when they are apart.

So here is the scenario. In picture 1 we have 4 magnets A, B, C and D. Magnets A and B are besides each other. Then C and D are completely parallel under A and B. I want to know that if there was a motor type of device that switched position of A and B to B and A (which becomes picture #2). I wanted to know that if after transition from picture 1 to picture 2 if the magnets would now become attracted or repelled if the transition was done.

Objective: I want to know this as polymagnets are expensive and big and was wondering if I compacted regular magnets in a certain way if I could get a similar result. Any help is greatly appreciated. Thank you!
 

Attachments

Last edited by a moderator:

Answers and Replies

  • #2
anorlunda
Staff Emeritus
Insights Author
8,646
5,538
polymagnets are expensive and big
I don't know the cost, but they can be very small. See the following video starting at 2:11


The video also discusses some obstacles, namely the relationship between spacing of the dots and thickness of the effect. Those are obstacles to the question you asked. So I think the answer to your general question is "Yes, you can make a DIY polymagnet. But no you can't design it with just a sketch, you need all the 3D dimensions, and distances, and magnetization, and permeability parameters to know if it will work or not."
 
  • #3
I don't know the cost, but they can be very small. See the following video starting at 2:11


The video also discusses some obstacles, namely the relationship between spacing of the dots and thickness of the effect. Those are obstacles to the question you asked. So I think the answer to your general question is "Yes, you can make a DIY polymagnet. But no you can't design it with just a sketch, you need all the 3D dimensions, and distances, and magnetization, and permeability parameters to know if it will work or not."
Yes I have seen the video. And yes I do understand it is more than a 2D drawing on MS Paint. I just wanted to know before trying a step forward or if to think of something else. Also you are right some of the polymagnets are quite cheap however the ones I require (twist release) can not be smaller than 3/4 of an inch and become expensive around 4-7 $ per magnet and my project requires around a couple hundred of them which made it quite unfeasible... However I found a lot of stores selling regular magnets as cheap as 20$ for 500 magnets that are small enough to make my project not a complete mess... Thank you tho for the video and I will look into more parameters of the magnets however. Thank you!
 
  • #4
sophiecentaur
Science Advisor
Gold Member
24,829
4,627
Way back, the only magnets that you could get hold of, to play with, were 'horseshoe magnets'. (I don't mean the plastic jobs with a small magnet on each arm) but the 'real ones' like this one. The local field between the poles was very much higher than could be obtained at the end of a simple bar magnet (made with steel in the old days). Two horseshoe magnets could be adjusted so that a rotation of π would switch between attraction and repulsion. It strikes me that the whole essence of poly magnets is based on the same thing and that there would be a lot of intuition gained by playing with a few horseshoe magnets without needing to spend too much on high performance mini magnets which would require very accurate and rigid positioning for an experiment to work.
 
  • #5
Way back, the only magnets that you could get hold of, to play with, were 'horseshoe magnets'. (I don't mean the plastic jobs with a small magnet on each arm) but the 'real ones' like this one. The local field between the poles was very much higher than could be obtained at the end of a simple bar magnet (made with steel in the old days). Two horseshoe magnets could be adjusted so that a rotation of π would switch between attraction and repulsion. It strikes me that the whole essence of poly magnets is based on the same thing and that there would be a lot of intuition gained by playing with a few horseshoe magnets without needing to spend too much on high performance mini magnets which would require very accurate and rigid positioning for an experiment to work.
That is an amazing concept. I had never thought about it that way... Very interesting, thank you.
 

Related Threads on If a magnet could switch, could it attract and repel?

Replies
8
Views
2K
  • Last Post
Replies
1
Views
1K
Replies
4
Views
2K
Replies
3
Views
764
Replies
3
Views
1K
Replies
3
Views
818
Replies
16
Views
5K
  • Last Post
Replies
3
Views
563
  • Last Post
Replies
0
Views
2K
Replies
2
Views
2K
Top