RCBS 505 scale keeps losing zero
- Thread starter 45C
- Start date
I don't think it's your bowl/pan holder with the weights in it but the connection between beam and pan holder,
the wire hanger on the end of the beam where the pan holder hooks into.
Maybe yours isn't moving completely freely due to being bent (not parallel or binding a bit) or having some sort of burr or something on the contact areas.
See link below, discussed in point 3 in the first post.
https://www.ar15.com/forums/armory/Tuning-a-balance-beam-scale/42-520054/
So, I removed the magnets again and put them back in and boom, works better than ever. And yes they were installed in the correct direction,just not perfectly aligned with each other.
The two magnets need to be perfectly aligned, which is not the easiest task.
The RBCS almost stops instantly now!
Thanks for all the help
The two magnets need to be perfectly aligned, which is not the easiest task.
The RBCS almost stops instantly now!
Thanks for all the help
Last edited:
Glad you got it figured out.
I knew it would be something fixable as the 505 is a great scale.
Another minor mod you should do is glue or tuck a very small piece of foam in the bottom of the groove where the copper plate moves in so that when you remove the pan the beam does not crash down on the metal base but drops on the foam.
I did this a couple of years ago, just didn't like the clatter without the foam. OCD is a wonderful thing.
lol !!
So, which way is correct? I'm assuming that they should be installed so they tend to attract each other, and not repel?
There's a magnetic field involved either way. The copper blade isn't magnetic, but it resists movement through a magnetic field, the same as a permanent magnet alternator armature does. If you had a current meter attached to the blade you'd see a very slight current being induced as the blade moved up and down through the field. Once it came to a stop, that current would be zero.
As I recall, the magnets are rectangular in shape. Having one rotated 180 around its long axis should change the magnetic field from attraction to repulsion, but what about removing one and putting the top where the bottom was?
I'm thinking back to a lot of years ago playing with 2 similar magnets, there was only one orientation that resulted in attraction, if you put them any other way they'd immediately want to spin to their "natural" orientation.
I'm hoping you know the answer to this. I can take mine apart and try it to see what happens, out of curiosity, but the scale works so well I don't want to fiddle with it to satisfy that same curiosity. Sleeping dogs and all that goes with them.
I don't have any extra magnets in my collection of possibles to try it, or I wouldn't ask the question.
They have to be inserted so that they want to stick together and they have to be aligned with each other very close to perfect.
The metal case that covers them has to be open enough so that you can’t see the top of the magnet.
The metal case that covers them has to be open enough so that you can’t see the top of the magnet.
The way they stick together you should separate them and keep facing each other that way when installing.
I did not know that the magnet positioning (with polarity in the right direction) was that critical to function properly so I learned something new here.
Yes it’s tricky to get them to align perfectly.
Also the metal cover needs to be open enough cover the magnets so you can’t see the top of the magnets.
That’s how it was in my new Oahu’s so I just mimicked that.
This is the bottom of my scale. The red arrow is pointing at a sheet metal horseshoe shaped retaining plate that holds the 2 magnets in place. The green arrow points at the magnet on the right end of the scale, there's another identical magnet under the far side of the retaining plate.
Mine doesn't seem to care that the retainer doesn't cover the magnet completely. It's super sensitive and settles very quickly.
This is an older version of the 5-0-5, maybe 20-30 years old? I got it used from an older gentleman several years ago. Probably US-made.
Mine doesn't seem to care that the retainer doesn't cover the magnet completely. It's super sensitive and settles very quickly.
This is an older version of the 5-0-5, maybe 20-30 years old? I got it used from an older gentleman several years ago. Probably US-made.
That metal retainer was spread apart enough so that you can’t see the top of the magnets, on my new ohaus,so I just did the same with the RBCS. They’re both the exact same scale as OHAUS makes both.This is the bottom of my scale. The red arrow is pointing at a sheet metal horseshoe shaped retaining plate that holds the 2 magnets in place. The green arrow points at the magnet on the right end of the scale, there's another identical magnet under the far side of the retaining plate.
Mine doesn't seem to care that the retainer doesn't cover the magnet completely. It's super sensitive and settles very quickly.
This is an older version of the 5-0-5, maybe 20-30 years old? I got it used from an older gentleman several years ago. Probably US-made.
Maybe it’s all in the alignment of the magnets but when I spread the retainer apart on the RBCS it almost stopped immediately,even quicker than my new OHAUS.
I think the retainer is stainless steel .
The RCBS 505 scale I have has always been very accurate probably more so than the 1010 Ohaus scale I have. Both are USA made by Ohaus not the Mexican or China made ones. But it would move around too easily and would have to be reset often. So I took a 1/4” piece of balsa wood and trimmed it to very tight fit on the bottom and filled up the cavity with lead shot. I have it sitting on a piece 1/2” plate glass and since doing that the adjuster wheel stays where I put it.
billbmcleod
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My old Lyman beam balance will repeat a weight consistently even though the magnetic damper magnet fell off years ago and I could not find it. If I zero it at the start of a forty round loading session it will be zeroed when I finish. Cycling damper is not an issue once I get to the trickle stage. I use an assortment of custom dippers made from brass usually of the same caliber machined off to a ball park throw weight with a nail soldered on for a handle and a piece of dowel on the nail. It just seems easier than filling a powder hopper, throwing a bunch of charges to get close on the low side and then emptying and cleaning the hopper.
I am not sure if Lyman would repair the damper or not but shipping costs might not make it worth it.
I always maintain with a beam balance that gravity does not lie or change!
I am not sure if Lyman would repair the damper or not but shipping costs might not make it worth it.
I always maintain with a beam balance that gravity does not lie or change!
