Hi,So with more windings and smaller wire, 3V battery should work?
Just add more windings (use a smaller wire dimension).
And with such home spun coils... Make sure it isn't a disaster if it stops working.
No, I just said it to yank your chain...Gee, I love it when my answers gets returned as "new" questions - a bit like saying "now are you really-really sure you meant that?"-
Because with the current setup the 3V did not even nudge the rod. I'll have to try and see, hopefully the battery wont discharge too fast.
No wonder. The wire you used is of a much too large gauge, so it's like a near short for your 9V battery and it's the internal resistance of the battery that has limited the current through the coil and kept the battery from melting down.
You need a wire of say 0.1mm in diameter and lots of windings - wind it on a thin walled plastic tube that the pop rivet fits in with just enough clearance to let it move freely. the former may be compressed a bit when winding it, so experiment to find the best former size, as well as the number of windings - count on using a couple of hundred turns at the very least.
However you make it, it will be sucking some juice, so don't use a lithium button cell for driving it.