Balance beam scale maintenance

[BoydAllen]

If you add weight to the end of the beam, which epoxying a piece of a needle will do, you can level the scale frame/body, put small pieces of something durable in the pan until the pointer is perfectly centered on the index mark, and them transfer them to the chamber in the bottom of the pan holder. When the scale body is out of level by very much, the knife edges do not bisect the angles of their supports, and this could affect the reliability of the scale's function. The first thing that I do when tuning is to readjust the pan holders tuning weights.

 

[RAD57]

When you re-insert the agates and screw down the retainers should the agates be loose in their pocket to float, seems that would give inconsistent weight measurements? Should the beam be installed with the agates loose so the knife edges align the agates before fastening down the retainers?

Figured it out. The agates are designed to float free. I had one agate free and the other wasn't due to corrosion under the agate on the 5-10 scale agate support nub. 5 minutes with Flitz polish on a Q-Tip removed corrosion & RCBS green paint and put a nice mirror finish on the nubs. The agates float around freely like they are supposed to. I also polished the loop in the pan support wire where there could be any possible friction with the end loop, and this step really increased the repeatability of the scales measurements. Before polishing, the loop could be repositioned on the end loop and have a .1 grain total spread in readings after polishing it centers every time.

 

[BoydAllen]

Good tip, I had not heard or thought of polishing the inside of the loop. Time to get out the Dremel.

 

[Brians356]

Once you get the scale tuned and set up the way you like it, it's best to leave it set up, and set something like an inverted shoe box over it to keep dust from accumulating on it. The less you handle it, the less chance of knocking something askew, or damaging the knife edges.

 

[RAD57]

When I was adjusting the lead weight in the RCBS pan I noticed that the weight change was weighing plus or minus .05 grain depending on where the pan support bend sat in the end loop. It didn't make sense reading different in the pan than outside the pan. Only difference was the removal and replacement of the pan ... that had to be the culprit! There was a little stiction from the sides and inside of the pan support wire where it was making contact with the end loop. I used my Dremel tool and Q-Tips with Flitz polish to put a high shine on the support wire and it really cured/helped in the repeatability of the scale.

 

[jrm850]

I was tuning up my old 304 a while back and found what looked like hot glue under the agates. The agates separated from the glue, but I never felt comfortable with just dropping them back in place. It seems to be accurate with the check weights, but I'm not sure I didn't changed the shape of the glue pads when I pulled it apart. I want to think that loose bearings would be better as long as they sit on a very flat base.
I'm about ready to either switch back to using this scale or spend more bucks on a 120i. Getting comfortable with the Gempro drift is a process. I would be interested to hear from anyone with 304 tuning experience.

 

[CatShooter]

Once you get the scale tuned and set up the way you like it, it's best to leave it set up, and set something like an inverted shoe box over it to keep dust from accumulating on it. The less you handle it, the less chance of knocking something askew, or damaging the knife edges.

My scale (an M-5) gets set up...

.. then taken down when I move.

 

[big bad bill]

I have an old Redding scale and removed the old, relatively weak magnets in the damper system, replaced them with some super strong magnets that are now available. This allows better action of the beam and faster measurements.
Bill