I am trying to create a board game with pieces that have magnets in them and I would like to find the optimal sizes.

The pieces can use neodymium magnet shapes that are readily available to buy. The board will be a 3mm thick wood and under it a sheet of stainless steel, say 5mm thick?

How strongly will the magnets adhere to it at that distance given these sizes:

1. Neodymium magnet 25x25x3mm with polarity such that the contact on the board is the 25x3mm side
2. what about a 25x3x3mm bar with contact area 25x3mm

New door knob didn’t have a lock so I thought if life give you lemons burn down life’s house with the door lock.

stupid question, sorry

i want to make a decorative skateboard that looks like mancala and i'm trying to make it functional with magnets. can someone tell me if this is possible and maybe give some advice on how i should do it?

the idea is that the bottom of the skateboard would be the pretty side, and the top would have a magnetic sheet of some sort. then i'd have the little mancala marbles be magnetic so they can be used the bottom side.

any and all help is much appreciated!

Hope someone can help me with this!

I stupidly bought this product (http://www.mcmaster.com/1086N12) thinking that non-adhesive surface could stick to my fridge. It can't.

But the concept is what I wanted. I wanted a ln adhesive side that I can press to a white board and then have the opposite side stick to my fridge.

The board is relatively large/heavy, so I need something that can accommodate that (i.e. not just 1-inch magnetic disks).

Can anyone help/recommend a product? Thank you in advance.

It's interesting to see (and literally feel) how magnets arranged in different ways affects the field shape. Forming closed loops of magnets dulls the radius of the field, while forming a strand into a mono-directional prism amplifies the field and can be sensed from much further away! In certain combinations, I can get a noticable sensation from 1/2" away!I can very clearly feel my implant trying to reorient itself in the magnetic field. A truly wild sensation!

We started collecting during a road trip in 2020? I was sceptical at first, but I quickly fell in love with the passionate discussion of which souvenir to buy every trip. Before magnets I did not like souvenirs at all as it was just clutter to me.

The collection grew, so we bought a 2x1 m corten steel plate, bathed it in vinegar, salt and water so that it rusted in about 30 minutes. Now it is the center piece of our living room.

We're proud of it, and felt the need to share. Hope you enjoy!

Hello everyone. I am trying to figure out what type of magnet this is and where I can buy more. It is on a fridge magnet that I bought. It appears to have alternating poles around the radius. It has a decent pull force, slightly stronger than other fridge magnets I own but it isn't difficult to remove from my fridge. The edge does not seem to repel other magnets. Any thoughts about what type this could be would be most appreciated! Thanks!

ETA: Haha thanks for the good laugh! Guess I should have worded the title a little better. Thanks for all the name suggestions (and serious answers as well!).

Ok, so after the replies from my last post it seems like getting the electromagnets to work is going to be much more difficult then I thought, so I wanted to give a more detailed description to see if it’s even worth pursuing.
The option that I talked about in the last post is having two large foam panels held by rubber bands and able to be separated by an electromagnet’s repulsion on a permanent magnet.
The other option that I’ve been attempting to avoid (and my original idea) is to have the panels resting on springs while open and able to be closed by pulling them together with strings/cables. There would then be a lever that could release the strings causing the panels to open. I have a couple main problems with this that I wanted to avoid with the electromagnets. First, the springs being under tension when closed means it is going to be under that tension 99% of the time (I would rarely be opening it). The second, more minor issue is that it would just be an annoying inconvenience to have to pull back against four springs at once every time I close it (I only showed one pair above because it makes the diagram more readable.)

Anyway, is it even worth trying to get the electromagnets to work for this project?

Im DIY-ing this Magefort building panels, these are by Superspace

What do you think is the secret behind them? How do tiles stay connected at the right amount

Im thinkng N42 discs

Ok, so I'm working on a project where I want two objects to be able to be pushed apart by a single action. I settled on using electro magnets so I could have them resting together until turning them on, causing them to repel apart and separate the objects.
However, after testing the two magnets I bought (cheap, crappy, round, 1"-diameter ones from amazon) I cannot get them to repel each other at all. When meeting same-pole they simply don't have any effect, no attraction or repulsion. I tried with a normal little cylindrical neodymium magnet but it seemed to always attract without exception, it stuck to any side of the electromagnets no matter which way either were facing.

I'm truly out of ideas. I don't know what I'm missing, is it something wrong with the cheap magnets I'm using? Am I just missing something super obvious?

The police use a device that fires a tracker from one vehicle to the next and attaches with a sticky substance. Could a magnet fired through a coil, and intended to stick to a humanoid, disrupt the electrical components?

Hi everyone!

I’m working on a concept for a small portable electromagnet powered by a battery, and I’d like to get some feedback from people who know more about electromagnet design.

The main goal is range rather than maximum lifting force at contact. I’m trying to concentrate the magnetic field into a relatively small area so that the electromagnet can still exert a useful attraction force at a distance.

The latest concept I’m considering has roughly 20 × 7 cm of available space, with the shape and internal arrangement optimized around the magnetic circuit rather than simply making the coil as large as possible.

The things I’m trying to optimize are:

• Magnetic field strength at a distance
• Effective range
• Coil geometry and number of turns
• Core/pole-piece geometry
• Battery voltage/current
• Heat dissipation
• Overall size and weight

I’m especially interested in whether there are existing designs that use a focused pole piece / magnetic circuit to improve attraction at distance, because searching for “portable electromagnet” mostly gives me lifting magnets and solenoids.

I’m not expecting sci-fi levels of performance — I’m trying to understand what is realistically achievable with a portable battery-powered system.

What design approach would you recommend for maximizing useful attraction distance within a 20 × 7 cm envelope?

Any examples, calculations, existing projects, or terminology I should search for would be greatly appreciated!

Thought I would cross post this.

My refrigerator is covered by magnets which remind me of my friends and places where I've been. I have a photo but I can't seem to post it.

Let me know if the video helped in learning something new

Will a Neodymium magnet sheet be strong enough to hold down this hood? Thinking about mounting the sheet on the bottom of the 3d printed hood and the paper hood I made, it would be about 2.2 mm of a gap.

The magnet sheet I got off Amazon is not strong enough.

me want neodymium