[Kreespa (OP)]

Hello all. Newbie here! Electrical engineer, so I should know this, but school was a while ago and I haven't worked in this field (hur hur hurrrrrr see what i did there?)

Anyway...

I'm in a scavenger hunt that lasts a week, and one of the items is to build an electromagnet that will catch iron filings poured from 20 inches away in order to spell a phrase. I've looked through a million build-it-at-home sites but I'm asking for advice here I'd rather not burn my house down, as it's where I keep all my stuff. I feel comfortable(ish) enough to make a basic one using a nail & wire, as shown in most of the videos, but any advice for creating a magnet/magnets that's bent quite a bit? And also how to attach them to a surface?

The actual specs are:

Set up a thin vertical surface that's at least 3' x 3'. Behind this, set up powerful electromagnets to spell a word or phrase (mirror imaged, so it is correct on the front side). Pour iron filings through a funnel at least 20" (horizontally) in front of the vertical plane so that when the fillings drop they are attracted to the magnets and adhere to the sheet in the appropriate word/phrase.

This item is worth quite a few points. I know I'm just a newb here butting in but one doesn't get help if one doesn't ask.

[RD]

... build an electromagnet that will catch iron filings poured from 20 inches away in order to spell a phrase ...

Suggestion :
Drill holes in a steel-plate to spell out the word, then magnetize the entire plate.
The filings should stick to the plate, but not the holes.   

Using a powerful magnet , say scavenged from an old hard-drive, would be much easier than making an electromagnet of equal strength.

NB: Iron filings are a hazard to eyes. A safer option is available ... https://en.wikipedia.org/wiki/Magnetic_field_viewing_film

[Kreespa (OP)]

thank you!

I'll look into that, however the rules are pretty strict on doing the items exactly as they say. I eventually have to make a video showing the filings jumping onto the plate.

I will also grab a pair of goggles if I get this working.

I did get the small nail-wrapped-in-copper-wire science experiment working, including a switch.. so I just have to figure out how to (safely) scale that up

[RD]

If you had five nail electromagnets in a row perhaps you could make a dot-matrix printer arrangement ...

Iron dust will leave a permanent mark on white paper.

or a less complicated solution : spell out the words in steel wire , (steel wool ?, paperclips ?), sandwiched between two sheets of card. Then place that sandwich on a flat steel plate magnetized by an electromagnet. The iron filings should preferentially stick to the steel wire words , [I think] ...


http://www.gonefcon.com/trucktcom/magnets.htm

You'll have to experiment with the plate-sandwich separation to obtain the optimum clarity of the message.

[Kreespa (OP)]

heheeeee i like the printer idea... perhaps if I have time.

Thanks for replying!