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electromagnet help!
Posted: Fri Jun 29, 2007 8:33 am
by spud yeti
Hey guys
I just wanted to pick your brains if any of you know how to make a strong and compact electromagnet? I need something that is pretty strong, so not just the wire wrapped around a nail method!
Please help!
Thanks in advance
Posted: Fri Jun 29, 2007 9:32 am
by pat123
I know this is the wire wrapped around a nail method but i got a 1/2 inch diameter nail wrapped it in wire and used three rechargeable remote controlled car batteries. each battery is 9.6 volts
Posted: Fri Jun 29, 2007 9:42 am
by spud yeti
Do you think it could pull something from about 3/4" that weighs about 10-15 grams?
Posted: Fri Jun 29, 2007 9:57 am
by pat123
yeah it lifted about 80 - 100 grams
Posted: Fri Jun 29, 2007 10:00 am
by Gepard
Google solenoid.
Michael
Posted: Fri Jun 29, 2007 10:05 am
by spud yeti
Thanks guys.
pat123, do you think you could please send a photo so I can see how long it is etc etc etc? I understand it and all that, I just want exact details!
Posted: Fri Jun 29, 2007 12:46 pm
by jimmy101
It is usually pretty hard to get significant magnetic attraction at a distance from the magnet. Spud Yete wants to "pull something from about 3/4" that weighs about 10-15 grams" Pat123 said his electromagnet "lifted about 80 - 100 grams"
Pat123's magnet may or may not be able to move 10 grams from a distance of 3/4". You need to compare the distance from the center of the obects being pulled/lifted to the face of the electromegnets iron core. The magnetic force will drop off as the square of that distance.
Posted: Fri Jun 29, 2007 1:01 pm
by SnowFlox
Use a coil from a Relay. thats a strong one.
Posted: Fri Jun 29, 2007 1:01 pm
by spud yeti
Yeah, in that case it could be almost impossible. Oh well, I guess it wont work then.
btw, it spud yeti, not spud yete... but that doesnt really matter

Posted: Fri Jun 29, 2007 3:21 pm
by psycix
what you want to use it for?
maybe we can come up with an alternative
(ive once tried to make a coilgun so if its about a quick magnetic pulse, im the man)
Posted: Fri Jun 29, 2007 3:39 pm
by singularity
does it need to hold the object in place or does it just need to get i to the magnet. you could hook up an electromagnet to a capacitor bank (you know like a few camera flash capacitors) that would be strong but the field would only be maintained for miliseconds. also remember how important resistance is in an electromagnet, the less current being draw the weaker the magnet, i suggest using 20 gauge wire
Posted: Sat Jun 30, 2007 12:16 pm
by spud yeti
It really was just an idea I had, and was curious as to whether it would work or not. I will post a diagram and some explanations soon!
Posted: Sat Jun 30, 2007 2:10 pm
by SnowFlox
so you want to activate a sprinkler valve with an electric magnet instead of escaping air ??
Like i said.. coil from a relay

Posted: Sat Jun 30, 2007 2:52 pm
by spud yeti
It was more to activate a piston in a co axial valve

But i was just thinking and trying to create something new... possibly better... but I dont think it would work so good.
Posted: Sat Jun 30, 2007 3:35 pm
by jrrdw
I was thinking about a piston valve that used a solinoid to move the piston but the problem was finding one that was strong and afordable. As soon as i can figure out how to use a Chevy starter solinoid without air leakage around the battery cables, i think that will work.