Does clustering magnets make them weaker?

Factual Questions
1

I’ve gotten a new washer and dryer, but the design of the door handle and the location of the dryer makes it difficult to open the dryer door. I didn’t want to drill into the door, so I obtained a set of rare earth magnets (this set, to be precise), made a simple ‘C’ handle out of scrap PVC, and sealed four of the magnets in
each end. It should be some 80 lbs of force, but the handle pulls right off the door. I tried them on a weight from my gym, and they barely lift 25 lbs.

I thought that setting 4 magnets next to each other would give me a cumulative force. Do magnets not work like this, or are perhaps the web site’s claim overblown?

2

If you put them so that like poles are adjacent to each other, they will be stronger:

N===S
N===S

But the like poles will repel each other, and unless the magnets are held strongly fixed in place, one will rotate, giving

N===S
S===N

This will be weaker.

3

Oh man, forgot about that. Now I gotta dig those out and redo this.

4

When you say you “sealed” them in: are the magnets contacting the door, or is there some thickness of PVC or tape or whatever between the magnets and the metal?

5

They contact the door, but the other sides are embedded in 2-part resin. I’ll have to drag out the Dremel and cut enough loose to pull them out

6

That’ll teach ya! NEVER use epoxy on your things until you’ve tested the design with less permanent glue :slight_smile:

7

Putting a metal casing around the magnet often increases its strength. They usually make custom ones for disk magnets.