Is my old scale busted?


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mljdeckard
October 18, 2011, 02:05 AM
Ok. So I just inherited a pile of gear, and I'm figuring it out one component at a time. Included is an RCBS 5-0-5 scale. I put it together with what appear to be the right parts from....the bag of parts. The trouble is, it's WAY off. I see there is a tray that unscrews in the bottom of the scale pan, with some bird shot rattling around it. Do I need to adjust that weight until an object with a known weight, such as a 230 grain bullet balances correctly?

It was a bit grimy and hammered when I found it, is is delicate enough that I don't want to give it the benefit of the doubt and chuck it?

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bds
October 18, 2011, 02:50 AM
Beam scales are delicate instruments not tolerant of rough handling.

I would give RCBS a call and see if they can factory clean/calibrate the scale for you, just in case there was some damage done to the scale.

RCBS seems to have excellent customer service and you might return with a post that says, "You won't believe what RCBS did for me." :D I haven't had the need to use customer service for my RCBS press and 10-10 scale as they are humming away happily.

Sport45
October 18, 2011, 03:03 AM
Do you have the powder pan on the scale?

Don't start dumping any of the shot from the balance. It's there for adjusting the balance to the pan that was shipped with it.

gamestalker
October 18, 2011, 03:51 AM
I have that exact same scale and have been using it trouble free for many years.
Anyway, nothing is broken or other wise malfunctioning. Put the entire scale back together again, except for the bird shot, keep that off to the side for what's next. OK, now adjust the front foot in untl the scale looks fairly level setting on the table, doesn't have to be perfect by any means for this step. Now hang the pan assembly on the back end of the beam where it normally hangs, the complete assembly except for the bird shot. Now turn the .1 grain or tenth grain wheel to absolute zero. Next set/slide the main beam weight to absolute zero. Now start adding bird shot until the pan starts floating pretty close to center line, or just some if it isn't possible to get that close to center with those shot sizes. Once you have it floating start carefully tunring the front foot until the pointer is alligned perfectly with the ceter line, your scale is now zeroed out.

Always use your scale on a fairly flat surface, and if the surface has a lean place the scale so either the pointer or the rear portion of the beam is facing either up or down hill.

How to use it. Every session requires the scale to be zeroed again. This is because once it's been moved it's orientation to level will usually change, and it doesn't take much of a difference to significantly effect accuracy and correct weight. Lets pick a powder charge of 11.3 grains. Turn the wheel until it is at 1.3 grs. and then slide the main weight to the first mark or notch which is 10 grs..

A charge of 6.4 grs.. Zero out the scale of course and then turn the wheel to the 6.4 gr. mark, done.

One more, zero out the scale, 66.8 grs.. Turn the wheel to 6.8 and slide the main weight to the 6th line.

I hope this helped. I remember how it was for me having to learn without the internet or any other easy source for information.
Welcome to THR!

sugarmaker
October 18, 2011, 10:44 AM
Instructions given here are pretty complete. i have a 505. if all 3 poises have weights (cut peices of sheet metal on 2 of them), and the pivot isn't broken you should be good. Make sure both beam pivots aren't damages and the pivots on the scale base is in good shape. Rattling in the scale pan holder is supposed to be there. Beam should have a copper damper attached on the pointer side - magnet in scale base damps motion. Nothing should drag. RCBS scale pans are gold in color and metal. Otherwise follow directions above and the scale should zero unless something's missing or broken.

Sport45
October 18, 2011, 11:34 AM
If you've dumped the shot, be sure to have everything in the powder pan, including the screw that holds it all together when you go through gamestalker's procedure.

ranger335v
October 18, 2011, 09:04 PM
The 'instructions' above are correct. Just understand that all you're doing is getting the beam, pan and pan hanger as nealy horizontal as possible. Then you can make the base 'zero' to match the beam. After that it should easily read correctly.

It's important that the knife edges on the pivot axel are sharp and burr free or the bearings will have too much friction to be consistant. AND we must keep the agate
V bearings clean and dust free. And the pivot axel must be centered in the bearings, without rubbing on either of the bearing retaining clips.

Hondo 60
October 18, 2011, 09:23 PM
Do I need to adjust that weight until an object with a known weight, such as a 230 grain bullet balances correctly?

A 230 gr bullet can be off by 2 grains or more, unless you've weighed it & know for sure that it is 230 grains.
If that's the case - never mind ;)

mljdeckard
October 31, 2011, 02:51 AM
I fixed it. What I think it was, the original owner (I bought it for my dad off ebay and he never used it) had taken some of the shot out probably to adjust for an extra pouring tool in the mix or something. Me and a friend started dropping #7s in it until we had to split the last one to get it perfect. :)

bds
October 31, 2011, 09:23 AM
Great! I love happy endings. :D

gamestalker
October 31, 2011, 01:51 PM
One last thought. If the rattling shot anoys you, just take a pair of pliers and flatten them a little, and they'll obviously stop rattling around.

Hondo 60
October 31, 2011, 09:09 PM
Glad to hear it.

amlevin
November 1, 2011, 01:19 PM
Biggest issue I've found with my 5-0-5 is that dust accumulates over time in the "bearings" which are two small hard V-Blocks at the pivot. A regular cleaning of them with some rubbing alcohol on a q-tip as well as the pivots returns the "repeatability".

I also have invested in a set of check weights. The combination of weights allows me to build a check weight in .5 gr increments. I use a combination closest to the actual weight I will be loading (that is when I am using the beam scale, not my chargemaster) to make sure it is not just accurate at "Zero". This isn't much different than just using a "Balance Scale" that uses actual weights rather than "poises".

rfwobbly
November 1, 2011, 01:29 PM
► The pivot blocks on a 505 are actually a gem stone called agate. And yes, they must be clean and dry. It's the same precision as having a "jeweled" watch.

► The knife edges of the beam's pivots must be sharp and rust free. I put Imperial sizing wax on mine to stop any rust.

rcmodel
November 1, 2011, 01:44 PM
Biggest issue I've found with my 5-0-5 is that dust accumulates over timeI kept my RCBS/Ohaus 5-10 in the box it came in when it isn't being used for most of 40 years. No dust.

Last fall I made a wood box "cover" that doubles as a scale platform to get the beam adjustments and 0 pointer up closer to Bifocal reading level.
No dust gets under there either.

rc

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