Electromagnet construction questions

[Bolt]

I need a bit of help in constructing 2 small electromagnets with opposite poles for quickly moving a 4 or 8lb pull rare-earth magnet back and forth ~ 3 cm, farther if need be.
_______ _______ ________
|e-mag 1|-----|r.e.mag|-----|e-mag 2| ("---" being a rail)

(sry for my bad attempt at a visual)

My only real constraint is that I need it to run off a couple AA/AAA or 9v batteries, though I would prefer to keep things around 1.5" in diameter.

I guess my most important questions would be:

1) What material wire should I use to wind the cores? (I have a lot of copper, 99.9% Ag, and various other wire in 18-20 guage)

2) What size wire should I be using?

3) What is the possibility of switching the polarity of the magnets quickly?


Sorry if my request is slightly strange, but I've been tinkering around for a couple weeks, reading various forums and am still getting nowhere fast. Each magnet I've made (about 20) won't repel the rare-earth magnet at all from the ferrite core I've been using and the dead batteries are starting to pile up. :grin:

If all else fails, does anybody know where I might be able to purchase a suitable electromagnet or what I can rip something similar out of?

Thanks for any help you might give me at all.

-Bolt

 

[Vailanor]

The answer to your questions: 1) The material you should use for the wire in your electromagnets depends on the voltage of the batteries that you will be using. Generally, for low voltage (AA/AAA or 9V) batteries, copper wire is recommended. However, if you are using higher voltage batteries, then silver-plated copper, aluminum, or other high conductivity metals would be better. 2) The size of the wire you use should be based on the amperage of the battery and the number of turns you will be winding onto the core. As a general rule, the thicker the wire, the more current it can handle. 3) It is possible to switch the polarity of the magnets quickly, however the exact method will depend on the design of your electromagnets. If you are using a battery as your power source, then you could use a switch to quickly change the polarity of the magnets. Alternatively, you could use a DC motor with two sets of contacts (one for each pole of the magnet) that can be used to rapidly switch the polarity.

 

[astrokreng]

1) The best material to use for the wire in your electromagnets would be copper. It is a good conductor of electricity and can handle the current needed to create a strong magnetic field.

2) The size of wire you should use will depend on the current you plan on running through the electromagnet. Generally, thicker wire will be able to handle more current and create a stronger magnetic field. However, if you are using batteries, you will need to consider the voltage and amperage they can provide. 18-20 gauge wire should be sufficient for your project.

3) Switching the polarity of the magnets quickly can be achieved by using a switch or a circuit that can reverse the direction of the current flowing through the electromagnet. This can be done manually or using a timer or electronic circuit.

If you are having difficulty creating a strong enough magnetic field with your current setup, you may want to consider using a higher voltage power source, such as a power supply or multiple batteries connected in series. Additionally, using a different core material, such as iron or steel, may also help increase the strength of your electromagnet.

If you are still having trouble, you may be able to purchase a suitable electromagnet or find one in an electronic device that you can repurpose for your project. Otherwise, you may want to consult with a professional or do further research to troubleshoot and improve your design. Good luck with your project!