Science Buddies: "Ask an Expert"

At the present time we are using a 5/8 " carriage bolt which the experiment called for. We insulated the carriage bolt & wrapped 12 windings of 12 G copper wire around the bolt. This will be our primary coil.We applied first a 6 V lantern battery to each end of the primary. we did not magnitize the carriage bolt enough to operate neef type vibrator. Next we applied 12 v to the primary. Still we did not magnitize the primary enough to operate the neef type vibrator. Could our problem be we are using too big size of carriage bolt? If we use a smaller carriage bolt do you think this will improve the magnitism? Is it possible to use 1 wrap of 12 G wire on the primary with A smaller bolt to generate magnitism throught the entire bolt? This experiment was listed on science buddies website.

rhino12 wrote:At the present time we are using a 5/8 " carriage bolt which the experiment called for. We insulated the carriage bolt & wrapped 12 windings of 12 G copper wire around the bolt. This will be our primary coil.We applied first a 6 V lantern battery to each end of the primary. we did not magnitize the carriage bolt enough to operate neef type vibrator. Next we applied 12 v to the primary. Still we did not magnitize the primary enough to operate the neef type vibrator. Could our problem be we are using too big size of carriage bolt? If we use a smaller carriage bolt do you think this will improve the magnitism? Is it possible to use 1 wrap of 12 G wire on the primary with A smaller bolt to generate magnitism throught the entire bolt? This experiment was listed on science buddies website.

This is a pretty popular project, and there are numerous threads on this forum about it. I'd do a search, and then post again if you don't find them helpful.

Also, the links provided off the sciencebuddies page are generally helpful. In particular, http://www.bizarrelabs.com/ind1.htm
seems to provide very detailed instructions for this project.

As always, be careful when working with high voltages.

Louise

Hi there,

https://www.sciencebuddies.org/mentorin ... ?from=Home

In your description you state that : "We are applying both 6 volts & also 12 volts directly to the bolt...".
However in the diagram in the link above (project description) it does not show to apply a voltage to the bolt. Instead the bolt's purpose, if I got this right, is only to act as a mechanical interuptor to the neef vibrator. The bolt will swing left to right due the changing magnetic field caused by the primary and thus connect and disconnect the primary loop.

I would think you want a material that reacts in a magnetic field. Did you try to see if the bolt attaches to a normal magnet ?

Hope this helps.

I hope you meant apply the current to the coil around the bolt.

Stainless steel is a "hard" steel as are tempered bolts. You need the properties of a "mild" or "soft" steel. Avoid bolts with hardness markings on their heads as they will be hardened.

Galvanized, tin, zinc, or nickel plating to inhibit rust will not affect the magnetic properties much so plating doesn't matter either way.