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Old August 12, 2011, 09:30 AM   #1
arizona hunter
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Balance beam scale innacurate-sometimes...

Just recently while using the "check weights" I noticed every weight is fine up to a combined weight of 22 grains, then it goes off by about .3 to .4 grains! The scale (Redding #2) has always been treated well, never used anything to clean it except a cotton cloth; is stored in a cabinet so it gets no dust, nothing is binding, no fans on, no A/C on, no magnets nearby (radio is about 15 feet away), no fluoescent lights either.

Note: the scale is not affected by position of the pan and the "hook" can only be attached one way.

Why is this happening?

Got so frustrated I ordered a Hornady Lock-N-Load Bench scale, it arrives today so I'll be curious to see if it is as good as nearly everyone says it is.
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Old August 12, 2011, 09:42 AM   #2
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Watch for items that can cause static. I think that cotton cloth could. As well as fans in the room that may be blowing too closely.
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Old August 12, 2011, 09:56 AM   #3
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I realize that you said, "no dust" but, I think that the knives and bearings need blowing off.
I use a soft one inch brush and/or Q—tip with a rolling motion using 90% alcohol and Canned air to blow off.
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Old August 12, 2011, 10:32 AM   #4
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Do you perchance have any .22 caliber match bullets (e.g., Sierra Match Kings) sitting around?

If so, put one in the scale and tell us what it reads.....

Last edited by mehavey; August 12, 2011 at 10:38 AM.
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Old August 12, 2011, 10:39 AM   #5
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If you have central heating and/or air, then enough airborne particles exist to eventually accumulate in the scale. You may have noticed that lab balances have separate dust covers for this reason. Buy it s bread box or a cake box.

Also note that most check weights sold for loading scales are not the highest class, and then can pick up funk from the air and finger grease and change. I recommend you find a compounding pharmacy that has a calibrated scale (theirs usually resolve 0.001 grams, or about 0.015 grains) and have them weigh your check weights. If they give you result in grams, just multiply by 15.432 to get grains.
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Old August 12, 2011, 11:11 AM   #6
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Quote:
I realize that you said, "no dust" but, I think that the knives and bearings need blowing off.
Not enough.

They need to be wiped completely clean.

NO OIL.

NO DUST.

NOTHING.

You should also not leave a balance beam scale with knife edges sitting on the edges when not in use.

Lift the beam off and place it near the scale.

The knife edges need to be sharp, clean, and perfect.
Even a tiny bur will affect performance.
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Old August 12, 2011, 11:27 AM   #7
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I should Have said Twisting not rolling, my bad.
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Old August 12, 2011, 01:51 PM   #8
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I don't know if the Redding scales have floating bearing blocks like the RCBS (Ohaus) scales. ...But, sometimes the blocks and perches have to "settle in", after the balance beam has been re-installed.
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Old August 12, 2011, 04:02 PM   #9
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Does your scale measure correctly if you go up to 40 and 50 grains. My redding scale goes off at around 20 grains but it is only .05 to .1. so. When I put 20 grains of weight on the scale it measures 20.05 or 20.1 grains. I'm just guessing at the .05 but it is less than .1. I load pistol ammo so I don't get much above 7.8 grains so I don't worry about it. As unclenick says the quality of the test weights are suspect. If you are as much as .3 or .4 off then I would give your scale a good cleaning with alcohol and a swab or wash it in dawn detergent and see if it works better. If not then you might call redding customer service and see what they suggest. Maybe it's just time for a refit?
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Old August 13, 2011, 03:49 AM   #10
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i noticed mine can be off too. the 7cc scoop i measured came out around 5.3gr one day. tested again and it came out 4.8gr. it kinda gets stuck on the low side. im talking about the metal part thats being dampened
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Old August 13, 2011, 05:40 AM   #11
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Using your forefinger, simply tap the table 4-5 time adjacent to the scale. It will immediately center to true/final reading.

As to a scoop measure being the standard for repeatability, well........

Last edited by mehavey; August 13, 2011 at 06:58 AM.
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Old August 13, 2011, 10:33 AM   #12
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Bee215,

You remind me that most balance beam scales these days are magnetically damped. The magnet that the aluminum plate slides between can attract iron particles, filings, and rust dust. If you get enough it will drag mechanically on the plate and spoil the readings. You want to lift the scale off the knife edge and slip a cleaning patch into the magnet gap; possibly with a little mineral spirits on it to help it pick debris up. Mineral spirits will dry off, but don't put any kind of oil in there as attracting dust won't help matters.
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Old August 13, 2011, 10:52 AM   #13
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Unclenick posted a very good response
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Old August 13, 2011, 11:44 AM   #14
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I've been using a balance beam scale for about 50 years without incident. I too put it away when not in use. I did find that when setting it up, I must put it in the exact same place on the shelf above my work bench if I don't want to adjust the leveling wheel each time. I keep my scale elevated so that I may see it straight on when seated. This insures more accurate reading.
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Old August 13, 2011, 11:57 AM   #15
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federali posted a very good response...
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Old August 13, 2011, 01:19 PM   #16
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"I keep my scale elevated so that I may see it straight on when seated. This insures more accurate reading. "

Yep. I get amused reading people who say a beam is "slow to use" and/or "hard to read." From bench photos I see on the web seems most people have their scale on the bench top and, often, remote from the powder dispenser and press; only worst place to put the scale would be under the bench.
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Old August 13, 2011, 02:08 PM   #17
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ill clean it to see if it helps
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Old August 13, 2011, 04:28 PM   #18
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I got so caught up in this thread that I to a rag and alcohol to my little redding scale and I seems to work better. A little dust out in the garage...
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Old August 14, 2011, 08:15 AM   #19
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BeeX - Your problem has nothing to do with the scale.

The spoons were calibrated using one batch of powder. Each batch of powder has a different density and therefore will weigh out differently. Every time you change the powder batch you have to recalibrate your spoons.

You can check the accuracy of your scale by getting a set of calibration weigths.

Spoons typically will drop light that is why they sell powder tricklers!
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Old August 14, 2011, 01:36 PM   #20
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I wish to thank everyone for all the information-this site always a lot of useful info.

I did use some alcohol to clean the knives, made sure cieling fan was off, in room a/c off, zeroed the scale and tried the check weights again...same thing. It gets to about 22-23 grains and then it's off.

Next I took the new Hornady Lock-N-Load Bench scale and plugged it in, let it warm up 15 min, did the set up/calibration and "checked" my check weights (1/2 grain, 1, 2 (2), 5, 10, 20 (2) and all weigh as listed (sometimes it read .1 over which is acceptable and all MFG I believe tell us to expect that). So, I guess I will retire the balance beam and go with the Hornady. Also, the Hornady comes with a "cover" with a hole in top to pour powder through, this cover allowed me to leave the nearby cieling fan on without causing any scale movement.

I paid $85.99 + 8.95 for shpping at Midway. Some places had it for less-but, out of stock for up to 3-4 weeks.

Thanks again everyone for all the suggestions/ideas.
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Old August 14, 2011, 01:46 PM   #21
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I think all those scales are OEM from Ohaus, so you could send the Redding in for repair. Don't know what they charge to fix an aging one, but Redding would tell you over the phone. Since the gauges in the electronic ones eventually fatigue, I like to keep a working beam balance around to double-check them from time to time, and you might like to get it back in working order for the same reason, then keep it in a covered bread box or something until you need it.
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Old August 14, 2011, 03:52 PM   #22
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Yep, give Redding a call they are nice folks. They have sent me magnets for my scales and an a hex wrench or two for some dies I bought that did not have them. (All free by the way) It doesn't hurt to have a spare scale, I have three. (Just worked out that way)
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Old August 15, 2011, 07:18 AM   #23
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Arizona.

Check to make certain that the hook on your powder pan is not too long or bent and that it is not catching on something. I have seen some that were too long and they would catch and not swing freely. It sounds like the pan is getting stcuk on something.

There is also lead filler in some pans. This filler may be shiftings around and therefore would give different readings. You can add some cotton to stop the shifting.
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Old August 15, 2011, 10:02 AM   #24
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I think the pan on that scale is on it's own knife edge, so position of pan lead weights, like that of powder in the pan, should not affect it.
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