This was covered on here before but I can't find the info now for some reason . . .

Didn't someone say that Radio Shack sold a cheap gauss meter (magnetic strength tester thingy)? I want to try matching up some of my motor and traction magnets.

I've seen prices online from $40 tp $400 for gauss meters . . . is this the right piece of equipment I need? :confused:

'doba

Radio Shack used to sell the parts so that you can build your own gauss meter for matching magnets.
Since the unit built will not be calibrated, it will not give you a true gauss reading.
But what it will give you is a number that you can use to compare your magnets.
Here is a link to build the thingy... But I do not know if the Shack still sells all the parts you need to build it.
http://my.execpc.com/~rhoadley/magmeter.htm

What am I thinking of then? Was it a thread about testing arms? What's that -- an Ohm meter?

Jeez . . .

'doba

Well, the Shack does have inexpensive ohm meters....

If you want a gauss meter I wouldn't waste my time with anything less than an F.W. Bell unit. The other cheaper brands will just go out on you and with no factory support any money you spent will just be wasted.

You don't need a new current model, and quite frankly you probably would freak at the price, but you can pick up a 10 year old digital unit for around 2-300 bucks which is about what the home made ones are selling for and there is no comparison between an F.W. Bell unit and one that some guy adapted an ohm meter to work as a gauss meter.

I get them from time to time if you want one....let me know. I also can explain what fixtures you need to build to hold the magnets and the probe to accurately compare magnets - otherwise you will just be looking at numbers that change on a readout and not know what the hell any of it means.


If you want a decent digital ohm meter you can get them for between 20 bucks and 60 bucks that are plenty good. Some 3 dollar cheapies have proven to be pretty accurate as well that are commy chinese ;-)

Try the old way. An old piece of rail on the top of a plastic film container. Fill it with lead pellets. add or subtract pellets.

Uh.......lead isn't attracted by magnets?

Uh.......lead isn't attracted by magnets?
No. Lead is not a ferrous metal...

Thats what I meant...no lead is not attracted by magnets... I guess the "?" threw you off.


Either way, 2 very different strength magnets could pick up a similar amount of metal. If you were using washers or something else METALIC even if the magnets picked up a difference as small as 1 washer, the magnets could still be way unmatched field wise.

Matched magnets matter as much as how strong a magnet is. I have made some pretty fast T-Jets with 2 evenly matched, but not so strong magnets.

Regardless of the scientific accuracy of a weight test, if you carefully read rayk's post, you'd understand that you don't need a magnetic ballast to do the test as he suggested.

Verifying that both magnets can pick up about the same number of ferrous washers will get you close enough.

Try the old way

... and for another really old "performance tip"

Keep it in the slot and practice, practice, practice...

BRP makes a nice magnet matcher. I have been using one for several years.
http://www.bat-jet.com/mm.html
Unfotunately the are out of stock, but I imagine they will be making more
hojoe

Someone else also made a magnet matcher with a magnetic compass and a ruler. Pur he compass at one end of the ruler, slide tour magnet along the ruler until the comapss needle swings towards the compass and record where the magnet is on the ruler.

Roger Corrie

You can practice all you want and that still won't make your cars motor so powerfull it will wheelie right out of the slot from a dead stop or a roll....

If you want a car fast enough to run a scale quarter mile from a dead stop in a couple or few tenths of a second, then I would assume you would mant a gauss meter.