SORTED Looking for small electromagnet

(OK, I know it’s not a sensor, it’s an actuator, so mods feel free to move this thread :D)

I’m thinking of using an electromagnet on the end of a robot arm to pick stuff up. So far the smallest one I found is here (14kg lift) but a tiny one that can lift a few 100g would do.

I know I can make one with an old nail and some wire, would rather buy one.

Anyone know of suppliers of small ones please?

TIA,

Jim

http://www.ebay.co.uk/sch/i.html?_trksid=p5197.m570.l1313&_nkw=electromagnet&_sacat=0&_from=R40

Thanks dc.... I always forget ebay!

But as it happens, I remembered there was one in my junk box. It came out of a copier / printer that I stripped- I think it was part of the door latch or some other kind of interlock safety thing.

It has no label so I took a flyer and threw about 10VDC into it and it seems to work.

For a small electromagnet consider making your own ?

Either way remember to drive it like a relay with a big enough transistor/FET and a free-wheeling diode.

MarkT: Either way remember to drive it like a relay with a big enough transistor/FET and a free-wheeling diode.

Yep... I might not control it from the Arduino at all, might just switch it manually straight from its power.

Bit of a hassle that these things seem to be 12v (it has no label though), but I tested it at 6v which is what the rest of the kit will use and it does work... I suppose it might not be as strong at low voltages but I want it to be able to lift a few washers or panel pins is all.

JimboZA:

MarkT: Either way remember to drive it like a relay with a big enough transistor/FET and a free-wheeling diode.

Yep... I might not control it from the Arduino at all, might just switch it manually straight from its power.

Bit of a hassle that these things seem to be 12v (it has no label though), but I tested it at 6v which is what the rest of the kit will use and it does work... I suppose it might not be as strong at low voltages but I want it to be able to lift a few washers or panel pins is all.

At half voltage it'll be about 1/2 the magnetic field and 1/4 the power dissipation - the power saving alone is probably valuable.

At half the magnetic field.it will provide one quarter or the lifting force. You can buy 6V solenoids via ebay if you need more lifting force.