This is not what you asked for, but it may help you out for the time being till you get your magnetic broom:
LOL , me either ! I was board and even asked if I could clean up to get the machine out. I did what I could and then he came out and put stuff right back. :o)
I hear auto AC clutches work , never got around to trying it myself. Someone ripped off my 10"x3"x3" computer magnet for picking up concrete nails and have been stumped on how to replace it.
The dirt concrete is funny. That's how the next door neighbor did his drive way. With about 10 people and shovels . I think about using dirt to just finish a job , but never can cause I need the biggest part under 1/8". I just hate crusing construction sites to steal sand.
OK. Here is a cookbook recipe for an 18" diameter AC electromagnetic sweeper that will give you about twice the pull of a microwave oven magnatron magnet over a diameter of 18" at a distance of 1" but it ain't gonna be cheap.
Take a 6" OD paper tube 6" long and mount it between a pair of 18" plywood disks with paper lightly gluded to the inside on the lathe. Get about 21,000' of #14AWG enamel wire (250 lbs) and wind 82 layers with 82 wraps per layer. Slop on some varnish every 2 or 3 layers. When you finish and the varnish has dried, strip off the disks and all but a couple of layers of paper from the tube. That will give you about a
400 gauss coil that will draw about 2.4 amps @120VAC.Make up a concentrator from a 6x6" soft iron round, a 20"x1/4" disk and a hoop of 1/2"x6" iron and fit it to the coil so it looks sort of like an angle food cake pan and fit the coil inside in a bed of epoxy.
You are now up around 320 pounds now so go out in the back yard and scrounge an old lawn mower body to mount it on.
One last word of caution. Disconnect your pacemaker before turning it on. :-)
Oops. You sure you wanna run this on AC? I bet the current will be a lot more than 2.4 amps!
The current would be *less* on ac, I suspect the impedance of this device at 60 cycles would be much larger than the dc resistance of its windings.
Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
On Mon, 26 Jan 2004 09:53:11 -0500, Glenn Ashmore brought forth from the murky depths:
Gunner was quoted as saying "Thank Abrasha it was made of a less magnetic stainless material or it woulda gone right through me."
----------------------------------------------------------------
Works great if your insulation on the wire is of zero thickness.
Gunner In the Dec 1996 Projects in Metal magazine there is an article on how a dude made a magnetic wand out of a automotive air conditioner clutch. Says he scrounges them for free from the repair places, melts down the alum housings. Worth a try and sounds like our kinda budget. lg no neat sig line.
That was 2.4 amps on AC. It would be a bit higher on DC which I would strongly recommend. AC electromagnets reverse polarity 60 times a second with nulls in between. If I were going to invest in 4 miles of #14 copper magnet wire I would definitely invest in some heavy duty diodes. :-)
The real complicati> >
.... and the gun held with the trigger in ever pressing condition awaiting for the evening boost of power as load sheds :-) Martin
Water cooled? :^)
This is the same with tape demagnetizers, they typically have built-in thermal trip-outs.
Which is a bother when you are degaussing something inside a mu-metal shield, and the thermal trip goes off in midstream. Magnetizes the item, *and* the shield!
Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
Well, yes. But it's a whole lot more correct than saying wire size is irrelevant, voltage is important.
Can also change results a bit if you go from round to square wire, or co-wrap smaller wire to fit into the gaps. Or of course if you change winding material.
When you get to the point where you need an electromagnet for nonferrous materials, let me know.
Pete Stanaitis
Gunner wrote:
I was thinking about the shorted turns presented by the disc and 6" round. Shouldn't an AC magnet be made of laminations rather tha solid steel?
Idealy yes but that would be a real PITA to fabricate unless he can find a really humongous transformer to salvage.
A very *good* reason to run this one on dc!
Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
Have you actually ever made one? I've got plans kicking around for one but never ran across 10 lbs. of surplus 14 ga. magnet wire cheap to wind one. That and the thick copper doughnuts...
As far as Gunner's dohicky, I made one a long time back with some magnetic welding ground clamps stuck in a length of wood and with a handle attached, used it for picking up roofing nails after we redid the house roof. These days I'd use either magnetron magnets or junk hard drive head positioner magnets. You can get either on the surplus market or from scrap gizmos. The bigger the hard drive, the better, as far as magnet salvage is concerned. Tack one edge of a chunk of canvas over the assembly to peel off the accumulation or just stick it in a trash bag and turn it inside out when enough has been picked up. I use the sacks my newspaper comes in and a magnetron magnet for picking up swarf around the place.
Stan
Sears sells them.
"This device is provided without warranty of any kind as to reliability, accuracy, existence or otherwise or fitness for any particular purpose and Bioalchemic Products specifically does not warrant, guarantee, imply or make any representations as to its merchantability for any particular purpose and furthermore shall have no liability for or responsibility to you or any other person, entity or deity with respect to any loss or damage whatsoever caused by this device or object or by any attempts to destroy it by hammering it against a wall or dropping it into a deep well or any other means whatsoever and moreover asserts that you indicate your acceptance of this agreement or any other agreement that may he substituted at any time by coming within five miles of the product or observing it through large telescopes or by any other means because you are such an easily cowed moron who will happily accept arrogant and unilateral conditions on a piece of highly priced garbage that you would not dream of accepting on a bag of dog biscuits and is used solely at your own risk.'
Exactly!
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.