Hi JDT,

I read your explanation but I do not understand it.

Needed is a scrap electromagnet to pick up metal chips. The chip load would be up to 250 lbs (~125 kg). The field needs to be deep (8 - 10 inches) to attract the chips. The electromagnet could not be greater than 18 inches in diameter. It would be possible to have a rectangular electromagnet 18 inches x 24 - 36 inches to gain more surface area. The chips are large (one would fill the palm of a medium sized hand). The chips are steel. Machine shop capabilities are available. Purchasing materials (metal, wire, etc.) and services (welding, fabrication, etc.) are not an issue. From a hand sketch I can create solid models and prints to build. I do not understand the information that I have read well enough to know where to start with design. Without design the project can't be engineered and built.

Any suggestions where to begin?

Have a good day,

Jim

 

Welcome to AAC!

Posting to very old threads is discouraged so you get your own new one.
Ref: https://forum.allaboutcircuits.com/threads/making-a-large-electromagnet.49474/#post-1249855

 

You may want to give some thought to a flat faced rectangular electromagnet type design and rather than try and wind your own consider an off the shelf turn key solution. By the time you do the wind and potting and form or machine a housing it would likely be easier to buy than build including buying for whatever available voltage you have.

Ron

 

Lots and lots of magnet wire and an anvil...

But seriously, what Ron said.

 

Welcome to AAC!

Posting to very old threads is discouraged so you get your own new one.
Ref: https://forum.allaboutcircuits.com/threads/making-a-large-electromagnet.49474/#post-1249855

Hi John,

Thank you!

I couldn't figure out how to start a new thread so I just tacked myself onto an old one.

Have a good day,

Jim

 

You may want to give some thought to a flat faced rectangular electromagnet type design and rather than try and wind your own consider an off the shelf turn key solution. By the time you do the wind and potting and form or machine a housing it would likely be easier to buy than build including buying for whatever available voltage you have.

Ron

Hi Ron,

I agree with you. However, the size, shape and capacity specifications that would work well for the application do not seem to be available from a scrap magnet manufacturer. I would be delighted if I am incorrect and someone can refer me to a supplier that makes what is needed.

The ideal unit:

- 18 x 36 rectangular
- lifting capacity up to 250 lbs
- magnetic field reach of 6 - 8 inches
- ON / OFF cordless remote control attached to the remote cordless crane control
- swappable batteries: unplug and remove (forklift battery type quick disconnects but smaller) weak batteries, install and connect fully charged batteries and recharge the weak batteries for nearly continuous availability of the magnet

Note: this is somewhat counter intuitive but for this application a weaker magnet with the magnetic field concentrated directly below the magnet would be an advantage because it would not be desirable for the magnet to be attracted sideways towards the side of a machine, an upright building I-beam, etc.

If it's not available then surely it can be built.

Have a good day,

Jim

 

Lots and lots of magnet wire and an anvil...

But seriously, what Ron said.

Hi,

I agree with Ron and you. Do you know of any suppliers that offer the type of magnet that would be well suited to this application? See reply to Ron.

Have a good day,

Jim

 

Another option is to get in touch with a magnet manufacturer or large distributor and talk to one of their applications engineers. Normally if these guys can't do it, they know someone who can. Most are rated ro pick up and hold a steel block so the chips may make things a little more complex. Adams Magnetic Products comes to mind as a a possible starter.

Ron

 

http://www.walkermagnet.com/scrap-magnets-liftmaster-lm-fab-series.htm

 

Another option is to get in touch with a magnet manufacturer or large distributor and talk to one of their applications engineers. Normally if these guys can't do it, they know someone who can. Most are rated ro pick up and hold a steel block so the chips may make things a little more complex. Adams Magnetic Products comes to mind as a a possible starter.

Ron

Hi Ron,

Thank you for the referral to Adams Magnetic Products. There are explanations on their website that have increased my understanding of electromagnets. Also, this looks like a helpful resource for product and information as they have "weaker" magnets that appear to be more suitable to this application than the standard scrap magnets that are capable of lifting very heavy loads. Thanks again!

Have a good day,

Jim

 

http://www.walkermagnet.com/scrap-magnets-liftmaster-lm-fab-series.htm

Hi,

Thank you for the link. I reviewed the website. This company and the others I have reviewed offer what appear to me to be industry standard sizes and lifting strengths. The sizes are too large and the lifting strengths are too great for this application.

Thanks again for the link!

Have a good day,

Jim

 

When they talk about POUNDS PULL, they mean placing a plate the same size as the magnet on the active surface and making sure the two surfaces are "lapped"
A 250 lb pull would be equivalent to 30 - 50lb in your case.

You need a core 18in x 18in to get the surface area to be able to pick up the scrap.
Simply get 9 old transformers and remove the E's and I's and use the 12v secondary to energise the magnetic circuit.
Put back the E's.
Put them all in parallel and connect to 12v battery. You may need to series/parallel them.