Can't get scales to zero...

[Arokcrwlr]

I have a couple of powder scales that I've had for quite a while that I do not use. I was going to give them to a couple of friends but I can not get them to zero. One scale is an RCBS 5-0-2 and the other is a Lyman 500. Neither will zero with the poises in the zero position, the pan in place, and the adjustment screw bottomed out.

Does anyone have a suggestion as to the problem and how to resolve?

Thanks.

 

[nvbirdman]

Are you absolutely certain the surface they are sitting on is level?
Side to side and back to front both.

 

[langenc]

Lyman will check and adj theirs if it dont work as expected.

Email em.

 

[tomiswho]

I've heard tell a florescent light can mess them up - don't know if I believe it or not - I have such a light over my loading bench. I have noticed lately a couple times my RCBS 5-0-5 wouldn't go to zero unless I rapped on the top of my tool cart. I have a bench high 5-drawered tool cart that I use as added reloading space and I keep my scale on it.

 

[Sonnytoo]

I think I would take a look at the "knife edges" and see whether they have been damaged, blunted, or whatever. I have taken a file or stone to those knife edges on my Ohaus 505 from time to time.
Sonnytoo

 

[flhr62]

I'm not sure about the 5-0-2, but on the 5-0-5 there is a screw in the thing that holds the removable pan, you can take the screw out and add or remove small shot as needed. I would check with a known weight after this is done.

 

[Enigma]

RCBS will also repair a scale at no cost - at least they did the garage sale 1010 scale that I bought.

 

[mattsbox99]

Easy fix, just elevate one end a little more. I have a 3/8" thick block of wood for the pivot end of my 505 scale as it also does not adjust far enough.

 

[Sgt Garcia]

Are you sure you have the correct pan for each scale. With both scales being off
the pans being switched is the first thing I would look at.

Dennis.

 

[J Miller]

As nvbirdman said make sure they are level. Also make sure they are clean. Get all the dust, lint, and debris off the pan, the pan holder, the bar and especially off the pivot bases and knife edges.

If that don't do, a trip to RCBS will. I don't suggest you mess with the knife edges as that can total them quickly.
I tried it, didn't work. Not lucky enough I guess.

joe

 

[Sgt Garcia]

JM is right; do your self a favor and don't mess with the pivot edges by trying to stone or sharpen, by doing so you would have to be VERY lucky or an expert to not mess up the scale calibration.

You never said how much they are off, a little may be corrected with level. If they are off a lot you need to look for something else. A little dust and minor dirt is not going to affect your scale appreciably.

Dennis.

 

[Arokcrwlr]

Thanks for all of the replies/suggestions.

I played around with switching pans, level, etc. and got the Lyman to zero consistently. The problem is I don't know how - the pans were paired correctly and my reloading bench is level. I have to raise the RCBS scale body on one end in order to get it to zero. I checked both against my Dillon beam scale and RCBS Chargemaster e-scale and they are both accurate. I feel confident that they both work so I'll probably go ahead and give them to friends.

Thanks again.

 

[GaSidewinder]

can you place a "known" weight in the pan and see what it shows as a weight. That will show you what to add or subtract on your pan to make it zero. Assuming you are on a level surface and have adjusted the feet up or down to zero it. I have one scale that actually requires that weight either to be added or subtracted to make it zero. I use #9 lead shot in a hollow cavity to balance it.

 

[islander]

My understanding is the screw foot is used only to level the scale, not intended to zero it. You can zero an out-of-calibration scale by adjusting the screw foot, but the correct method is to add or remove weights from the weight pan with the scale perfectly level, until the beam pointer is dead-on at zero.

 

[gmaske]

My understanding is the screw foot is used only to level the scale, not intended to zero it. You can zero an out-of-calibration scale by adjusting the screw foot, but the correct method is to add or remove weights from the weight pan with the scale perfectly level, until the beam pointer is dead-on at zero.

Standard practice with setting up my RCBS 10 10 is to set up the scale and zero the weights and then adjust the leveling screw until the scale is zeroed. The I beam when balanced at zero will be perfectly level. You then level the rest of the scale with the I beam.

 

[Sgt Garcia]

Islander, the screw foot is actually intended to be used to zero the scale provided it is relatively close to begin with.

gmsaske, your method is correct except the beam will not necessarily be level when zeroed, nor does it need to be for accurate weighing. Neither the base nor beam needs to be "level" end to end for this type of scale to weigh accurately. The beam just needs to move freely and the pointer needs to start at zero on the chart.


Dennis.

 

[islander]

Thanks for setting me straight. I checked the instructions on my 10-10 and sure enough they call for the screw foot to be used to align the beam pointer at zero. Now if I could only remember why I didn't read those instructions before...

 

[GaSidewinder]

Reading the Lyman scale instructions it says:

"Set the assembled scale on a secure level surface free from drafts or vibration. Move both poise (balance weights) to the "zero" position and adjust the leveling screw under the left end of the base casting until the beam pointer rests on "zero". Rezero the scale everytime you use the scale"

The leveling screw is used to zero out the scale.

As I had mentioned before, if the above does not zero the scale you must add or subtract weight from the pan to make the scale "zero". Unless as someone else mentioned that there is damage to the knife edges or some other reason for the problem.

 

[Sgt Garcia]

Thanks for setting me straight. I checked the instructions on my 10-10 and sure enough they call for the screw foot to be used to align the beam pointer at zero. Now if I could only remember why I didn't read those instructions before...

Now now, no need to start a bad habit like instruction reading!!! :shock:

Dennis.

 

[Pal Val]

The Man Rule: "When everything else fails, read the instructions."

:lol: :lol: