RCBS 10-10 scales

[Kestral]

Need info on 10-10 scales, correct set up details followed,empty pan registers zero. put in 5 grns powder,scale registers 5 grns.finger tap pan,and scale registers 5.3grns.RCBS state beam is dampened,so should I set up .03 short of 5 grns to be correct.Thanks for any help.Kestral

 

[rcmodel]

NO.
Something is wrong!

It should balance at 5.0 grains and continue to balance at 5.0 grains again if you tap the beam.

There are two other threads just below yours, very similiar to yours, with a lot of answers to your question.

http://www.thehighroad.org/showthread.php?t=411418

http://www.thehighroad.org/showthread.php?t=411444

rcmodel

 

[Kestral]

Many thanks for your reply rc model,very much appreciated Kestral

 

[Ol` Joe]

NO.
Something is wrong!

It should balance at 5.0 grains and continue to balance at 5.0 grains again if you tap the beam.

There are two other threads just below yours, very similiar to yours, with a lot of answers to your question.

I have to disagree with this.
I`ve a RCBS 5-10, 10-10 and Pact digital and all, if a given wgt is trickled in the pan, gain a tenth or two when you tap the pan. I always drop a charge, trickle to just under wgt then tap to see if it hits the desired amount.
I believe the cause is hystasis (sp?). It`s a inerta related event and isn`t a problem as long as you understand it is there. The beam on my scales always seems to stop at the same point and my Pact also is extremely repetable in its movement.

Try it, trickle a charge, say 20.0 gr then tap the pan. You`ll likely see the poise stop at 20.2gr or some similar point. Every time you tap after the initial one will have the scale stop at the same 20.2gr wgt, trickle a new charge and it starts anew.

 

[ranger335v]

Bearing contamination and/or friction WILL cause scale problems such as you are encountering.

Check the pivot beam for cleaness. And see if the pivot bar is rubbing against the clips that hold the V bearings. The beam must be centered to work right, it is critically important that the pivot bar of any balance beam scale NOT touch anything BUT the bearings.

Hysterisis is an electical problem, we may encounter it in digital scales. It's a condition in which a circuit is reluctant to change states when small forces are slowly applied, makes it hard for a digital scale to follow powder trickers. It's not applicible to beam scales tho. And the magnetic damping system on our balance scales has absolutely NO effect with the beam is not moving.

 

[NotSoFast]

How do you know for sure you are putting 5 gr in the pan? Are you also measuring it with a second, known accuracy scale?

Now that I got mine working, it is consistently within 0.1 gr of my electronic scale all the way from zero to the biggest calibration weight I have.

What I have started to do before I use it each time is go back and forth between scales two or three times with the same weight until I am satisfied they are both reading the same.