# Magnet matching on the cheap?



## super8man (Jan 29, 2013)

After reading an ebay auction, I trudged over to Harbor Freight and picked up a "US Balance" US-Magnum-1000XR professional precision pocket scale for $10.99 plus tax.

The nice thing about this scale is it comes with a removeable plastic cover and a metal plate used as it weighing platform. Like the ebay auction item I saw, I drilled a 5/8ths hole into the plastic cover directly over the circular control panel. I am now able to operate the scale without removing the cover.

I then press the on button, wait for it to zero, then I place a t-jet magnet on the plastic cover and read the negative gram reading. My values range from the low 4s/high 3s all the way up to 14grams with most of the red and white magnets falling into the 7,8 or 9 gram range. I have made a small plastic container to group my magnets and look for balanced pairs (or to locate stronger rear magnets to facilitate braking).

Feel free to lend your thoughts on this methodolgy. For $10.99 it was the simplest solution I could find and the scale also doubles as a "scale" to weigh my cars. 

Good luck!


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## Bubba 123 (Sep 10, 2010)

super8man said:


> After reading an ebay auction, I trudged over to Harbor Freight and picked up a "US Balance" US-Magnum-1000XR professional precision pocket scale for $10.99 plus tax.
> 
> The nice thing about this scale is it comes with a removeable plastic cover and a metal plate used as it weighing platform. Like the ebay auction item I saw, I drilled a 5/8ths hole into the plastic cover directly over the circular control panel. I am now able to operate the scale without removing the cover.
> 
> ...


it will never pass Government Inspection...
2; easy, cost effective, and reliable... :freak:

u'r a Genious :thumbsup:
TY :wave:

Bubba 123 :wave:


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## Solo2racr (Dec 26, 2012)

I have been using the same scales for a couple years to measure comparative magnet strength. It works well.


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## Dyno (Jan 26, 2009)

Solo2racr said:


> I have been using the same scales for a couple years to measure comparative magnet strength. It works well.


I second that. You can also use it to check a cars downforce strength vs another car.
Also it's a good idea to mark the clear cover so you always test the magnets in the same place. Different areas of the scale will give a different reading.


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## ParkRNDL (Mar 20, 2002)

I have the same scale and use the same method with one exception... I drilled a second hole over the mode selector button and before I start measuring, I set it to "grains" (I think that's the setting), which is much more precise. Standard Tjet magnets come in around 60, MagnaTractions are something like 180 if I recall correctly. I may be a little off on the numbers, but the point is you can get a more precise comparative reading using the smaller increments...

--rick


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## ruralradio (Mar 11, 2011)

Ditto here. I marked the cover to the center of the plate for fairly consistant placement of the magnets. Not as precise as a gauss meter, but much cheaper, and I'm no rocket scientist.....


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## eastside johnny (May 13, 2008)

Roger Corrie did a full write up here a while back with pictures etc. Real nice. You'll have to do a search to locate it. Great tool.


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## ajd350 (Sep 18, 2005)

Works for me. The cars I run are matched with that scale and are very fast and competitive. I could spend more, but the results speak for themselves. Just ask the guys I race with.


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## racer8nut (Mar 25, 2010)

Just got mine this past Saturday. Now I am looking forward to matching my Magnets. Also it could be used to measure the magnetic downforce of your traction mags. THanks for the great find:thumbsup:


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## beast1624 (Mar 28, 2009)

Also works great for weighing the bodies when you have a limit in a particular class. Once we were wondering why a particular rear axle in a Mega G ran so much faster than the others so we weighed it and found it was @ 35% lighter. Great tool for a great price. Also watch for when HF puts their digital calipers on sale for around $10...another must have tool.


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## JUNKCARRACER (Dec 10, 2012)

*magnet matching 440x2 magnets*

what kind of gauss meter do i need to match 440x2 magnets


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## Hornet (Dec 1, 2005)

The scale tip works very well,but if you want an actual little guass meter.
Greg builds and sell 2 differant varieties that are pretty decent.
If you ever plan on stepping up the magnts in your 440's,go for the more expensive meter with the wider range

http://www.hobbytalk.com/bbs1/showthread.php?t=385052


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## oldraceral (Dec 1, 2005)

I use the same scale for pickup shoe tension. Built a platform and drilled a few (!) holes. Added a short plastic push rod and now I can adjust all my cars' shoe tension.


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## super8man (Jan 29, 2013)

Nice thinking on the pickup shoe tension...can you post a picture of the workings of your scale? Like a sideview show to understand it a bit better? Nevermind, I now get that you are not using it for magnet matching...heck, they are cheap enough, buy two! Yeah, I think you could even use the normal plastic cover to fabricate a plastic rod to push on the scale. I am guessing the plastic cover you have is to avoid the magnetic attraction of the scale.


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## oldraceral (Dec 1, 2005)

The legs are about 7/8" long and the push rod is just long enough to replicate a track rail height. You don't want the pickup shoe to bottom out and weigh the chassis. You only want the spring tension. Set the platform over the scale and insert the push rod. Zero the scale and place the car with the shoe pushing on the rod. I tried to show it in the second pic but the rod is covered by the pick up shoe.


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## super8man (Jan 29, 2013)

Even better than I expected. Thanks. Nicely done, cheap and simple.


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