Designing and setting up a strong electromagnet

Thread Starter

zazend

Joined May 31, 2016
7
Hello guys, and thank you for your response in advance. I am new to this forum, as I am new to the science of electromagneticism.
Now, the reason I am posting is that I need your help with a project I am currently just starting and of which unfortunately I have little details figured out as well, so please bear with me if you will and I will try to provide as many information as best as I can on request.

So here we go: I am looking to design and create a source of magnetic field of which I want to be able to control its strength, hence I suppose I am looking for an electromagnet.
Its intended use will be to be able to make flexible rods (material of rods yet undicided) to bend towards it. Now these rods are expected to be a few inches thick (lets say between 1.5" to 3" thick), one end made immobile on the ground and I would guess a length of say close to one (1) meter or so.
What I would also like would be to be able to affect, using a single electromagnetic setup, more than one such rods, the closest of which would be, say, 3 meters away from the electromagnet and the farthest about, let's say 8-10 meters away.

Regarding the power, I am already guessing I will be needing some shorts of heavy duty power generator (contrary to the typical capacitor relays used in DIY home experimental projects).

With regards to temperature, let's just suppose I may be able to choose from the absolute minimum options out there (yet unknown/undecided but I'd say water(?))

So, bearing in mind that I have only a vague idea of this project (note: it is not in nature an industrial or of great precision project), could you guys provide me with your thoughts and a few directions for me to consider and explore?
 

shortbus

Joined Sep 30, 2009
10,045
Now these rods are expected to be a few inches thick (lets say between 1.5" to 3" thick), one end made immobile on the ground and I would guess a length of say close to one (1) meter or so
Can't see any way possible for that to work with a electromagnet. It would take a hydraulic press of a hundred or more tons to do this, way beyond the strength of a magnet.
 

Thread Starter

zazend

Joined May 31, 2016
7
Can't see any way possible for that to work with a electromagnet. It would take a hydraulic press of a hundred or more tons to do this, way beyond the strength of a magnet.
Do you suppose that I could pull it off by making the rods 0.5" or do you suppose it would still be impossible? How about if I reduced the desired distance between the electromagnet and the rods to a range of 0.5m to 1.5m - 2m?
 

Thread Starter

zazend

Joined May 31, 2016
7
I'm not going to do the reading for you, sorry. But will link you to Google - https://www.google.com/search?q=force+required+to+bend+steel+rod&ie=utf-8&oe=utf-8
Thank you for your train of thought. As I mentioned in my original post, I have not yet decided on the material of the rods. My main concern in this post is the limitations to building such a strong electromagnet, ie heat due to resistance, required energy, etc.

I will be giving a read to the bending forces search though. Thanks a lot for your time.
 

Alec_t

Joined Sep 17, 2013
14,327
Have you actually tried bending a 1m steel rod 0.5" in diameter? You will be surprised how much force is required. Even if you reduced the diameter to 0.5mm (e.g. use a length of piano wire) you would need an enormously powerful magnet to bend it noticeably from a distance of 1 metre.
 

Thread Starter

zazend

Joined May 31, 2016
7
Have you actually tried bending a 1m steel rod 0.5" in diameter? You will be surprised how much force is required. Even if you reduced the diameter to 0.5mm (e.g. use a length of piano wire) you would need an enormously powerful magnet to bend it noticeably from a distance of 1 metre.
I appreciate your time and input, however I am not narrowing down my options to steel for the rods. In fact I am currently looking for more flexible materials that can interact with a magnetic field. I just don't want to go as far as fibers.
 

Thread Starter

zazend

Joined May 31, 2016
7
A new design idea has come into play, according to which the rods are of an elastic material, with a ferrous material on the upper tips to facilitate the bending due to magnetic forces.
 

wayneh

Joined Sep 9, 2010
17,498
What is the purpose of bending the rod? I mean, if it's just for looks, there are many other ways you might accomplish this illusion. If it has to be due to a powerful magnetic field, then could the rods in fact be very flexible with just a piece of iron at the top to respond to the field?

I'm just saying, we might offer better ideas if we had a clue what you are doing. Bending a 3" steel rod from 10 meters away isn't going to happen.
 

Thread Starter

zazend

Joined May 31, 2016
7
What is the purpose of bending the rod? I mean, if it's just for looks, there are many other ways you might accomplish this illusion. If it has to be due to a powerful magnetic field, then could the rods in fact be very flexible with just a piece of iron at the top to respond to the field?

I'm just saying, we might offer better ideas if we had a clue what you are doing. Bending a 3" steel rod from 10 meters away isn't going to happen.
The purpose of this is to create the desired motion for artistic purposes. So, yes, the more I think about it the more I am convinced I should go with a combination of materials to facilitate bending and magnetic force as the drive.
 

wayneh

Joined Sep 9, 2010
17,498
That could totally work. I was even thinking of using memory wire. Basically, that stuff can assume a different position when electricity is applied to it. I think you could create the illusion of big metal rods bending in a field when it's really a foam pool noodle, painted to look like metal, bending over due to a wire inside it. There might be a hydraulic solution also. Kind of like Viagra in reverse. :eek:
 

Sensacell

Joined Jun 19, 2012
3,451
I second abandoning the magnetic field idea, the forces and distances involved make this a non-starter.

The idea of using a wire inside of a flexible form is very workable- Google "steerable catheter" for examples


Image 2_Sensei X2_Inner and Outer Guides.jpg
 

djsfantasi

Joined Apr 11, 2010
9,163
Or a mechanical solution of cables routed through circular plates... Servo motors could be used to move the cables and bend the "rods".
 

Kermit2

Joined Feb 5, 2010
4,162
What about old school
Fix rods to an axle, add counter tension with a spring (hide it below axle. Use old fashioned solenoid to pull and rotate axle.
When released, spring returns "rods" to upright position.
 

Thread Starter

zazend

Joined May 31, 2016
7
Wow! Back from work and I have lots to read through and study about! I will be checking all those amazing suggestions and will surely get back to you guys for an update for anyone interested!

Thank you all for your contribution and input, despite the fact I had but a vague picture of the project to provide. Still, it's so exciting getting to interact with you here! Big cheers, much obliged!
 

BR-549

Joined Sep 22, 2013
4,928
I still don't understand the structure and dynamic that you are looking for.

Would or could lighter non conductive materials using electrostatic charge be easier to implement?

Have you ever played with an electroscope or static charge? Get some balloons, glass rods and a dry cat.

You can suspend materials from fishing line. You would be surprised at what can be charged.
And how they react to an external charge.

One can attach and apply charge foil to a non conductive material. And then move that material with an external charge.

Many, many possibilities. No high currents.
 

cork_ie

Joined Oct 8, 2011
428
What you are looking for does exist , electromagnetics are widely used in the scrap metal industry to separate ferrous and non ferrous metals.
The only problem is they weigh a lot and you will have the magnetic force field to contend with as well, so a 20 tonne crane would be probably be part of your project. It is worth having a quick look just to get an idea of the possibilities and your budget requirements.
http://www.walkermagnet.com/lifting-magnets-battery-powered-lift-magnets-wbp-series.htm
 

shortbus

Joined Sep 30, 2009
10,045
What you are looking for does exist , electromagnetics are widely used in the scrap metal industry to separate ferrous and non ferrous metals.
I have my doubts that a lifting magnet would be able to bend a 1 1/2" to 3" diameter, 1 meter long steel rod mounted in a cantilever configuration from 1 to 8 meters away. This was the original question.
 

Kermit2

Joined Feb 5, 2010
4,162
Almost any huge magnet will be pitifully weak at a distance of 1 meter. More distance than that and only a compass would detect where the magnet is.
 
Top