I have some questions about my project. I want to make a big electromagnet, the size is about:

Outer Ring:

  • 50-70cm Height
  • 35cm Diameter

Inner Ring (The Movement):

  • 32cm Diameter


  1. is it OK to use 1mm copper wire?
  2. How much voltage do I need for a nice movement?
  3. Must the inner ring be a whole magnet, or is it OK to make many small magnets on the inner ring?

enter image description here

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    \$\begingroup\$ what does this mean? for a nice movement \$\endgroup\$ – jsotola Jan 9 '18 at 7:11
  • \$\begingroup\$ you need an iron core for the electromagnet \$\endgroup\$ – jsotola Jan 9 '18 at 7:12
  • \$\begingroup\$ So for the inner ring , no magnets just an iron core ? \$\endgroup\$ – M6Gpower Jan 9 '18 at 7:14
  • \$\begingroup\$ A silicon steel core, or ferrite if the OP is rich enough... \$\endgroup\$ – VTNCaGNtdDVNalUy Jan 9 '18 at 7:14
  • \$\begingroup\$ There is no budget given so no worries there!! \$\endgroup\$ – Solar Mike Jan 9 '18 at 7:32

is it okey to take a 1mm Copperwire?

Yes. A single layer 60cm long will have 545 turns and need 600m of wire.

How much Voltage do i need , for a nice movement?

13 Volts. The coil will draw ~1 Amp. The movement will be very nice (synonyms: enjoyable, pleasant, delightful, entertaining, amusing). You could use up to 65V (which should draw 5A) but the coil will get hotter and the movement could get quite ugly.

Must be the inner Ring be a whole magnet or is it ok , to make many small magnets on the inner ring?

It's OK to put many small magnets on the inner ring - if you can get them to stay there. The magnets should all be oriented in the same direction, eg. north pole up, south pole down.

Resources used for calculations:-

Solenoid calculator

AWG gauges and their current ratings

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  • \$\begingroup\$ Thank you for the very good answer ! -That is huge length of wire, is it possible to use a 2-5mm Copperwire with 12v and i will still get the nice(smooth) movement or how is it with the movement? Do i need for a bigger wire more voltage or less? I think the current is the point for the movement right? \$\endgroup\$ – M6Gpower Jan 9 '18 at 19:09
  • \$\begingroup\$ Magnetic field strength is proportional to both current and number of turns. Stronger magnetic field creates more force and faster movement. Current is determined by Ohm's Law (I=V/R) and so can be increased by raising voltage and/or using thicker wire. However increasing current and/or voltage also increases power and heating (P=IV). If the coil gets too hot it will melt or burn. \$\endgroup\$ – Bruce Abbott Jan 9 '18 at 23:03

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