Beam Scale Question: Ohaus 10-10 vs RCBS 5-0-5

[otisrush]

I have an Ohaus branded 10-10 scale. It was part of a set of equipment I bought from a guy a handful of years ago when I started reloading. He spoke highly of this scale when I bought his gear, and I've seen others on the net speak highly of it.

One thing I noticed a while ago is the beam has some front-to-back play when it's sitting on the stones. I had this sense that things weren't moving as freely when that beam was pushed toward the back, as opposed to being pulled forward. So I try to keep it not pushed to the back. But I'm getting into rifle calibers where I weigh every round. All that pan on-off makes me concerned I'm moving the beam around and maybe getting it into the "move not so smoothly" zone.

I also happen to have a brand new RCBS 5-0-5 scale. Tonight I got out both and started playing with "repeatability" of going back to zero when lightly tapping the pan, trying it in both directions. (Meaning tap the pan down lightly, so the beam pointer goes up, and see where it settles. And the reverse, tap the pan up lightly so the beam pointer goes down.)

Overall I'm seeing better repeatability in the 5-0-5. That scale does not have the front-to-back beam play that the 10-10 does. In general the 10-10 settles on the high side of 0 when I tap the pan down. And slightly on the low side of 0 when I tap the pan up.

I think I'm leaning towards using the 5-0-5 as may main scale. But this feels odd because of how I've seen people comment so positively on the 10-10.

Any thoughts on this? Maybe I'm overthinking all this, but it bugs me that where the beam pointer seems to settle is (to a certain degree) dependent on which side of zero it was moved. Any 10-10 users out there have this front-to-back play I'm talking about?

Thanks.

OR

P.S.: The surface the scales are on is level, both left-to-right and front-to-back.

Also, for those that might say "Go get a digital scale." I'm only interested in that if you think neither should be used. I like beam scales and I have very little desire to go buy a new scale.

 

[Havok7416]

I've never heard anything bad about Ohaus and they in fact make the majority of the scales out there. I don't own a 10-10, but I do own a Dillon Eliminator and an RCBS 5-0-5. Both have worked faithfully for quite some time.

How far off is the needle? 1/10th or more? I'm not sure less than that would bother me much, but if it does, just use the 5-0-5. You can always keep the 10-10 on the shelf.

Regarding electronic scales, I was like you and didn't want to spend the money. Recently though I picked up a Smart Weigh GEM20 scale based on some testing a THR member posted here. It's only $20-25 and can be found pretty easy. I was surprised how accurate it is and how easy it is to use. I think of it as a lot of piece of mind for not a lot of money.

 

[Swampman]

I don't have a 505 to compare with, but I have used the same 10-10 for over 30 years.

I've been dealing with the issue of the blades sliding back and forth in the agate bearings for so long that I haven't thought of is as a problem for years. I've found that accuracy and repeatability suffer if the beam is either too far back, or too far forward.

I'm very careful to make sure the beam is centered between the bearings when I zero and I try to pick up and replace the pan smoothly so as not to cause any back and forth movement of the beam/blades.

No matter how careful I am, I'll still screw up occasionally and cause the beam to be knocked slightly off center. Years ago I developed a technique of recentering the beam by "pinching" it between my thumb and forefinger while I rest the knuckles of said digits on top of the scale body.

I'm doing a poor job of describing the operation, but I've done it (and checked zero) so many times that I no longer even bother to recheck the scale after accidently bumping the beam off kilter. As long as I recenter it, it always returns to proper zero.

I had never tried anything like your "bump up, bump down" test but I just did (excellent idea by the way). I didn't notice any tendency for the beam to stay either up or down when bumped in a particular direction. As long as the beam was centered between the bearings, the scale returned to zero whether the pan was bumped up or down.

The more I think about it, the more I believe that both of our 10-10's are probably either excessively worn or damaged. Mine was brand new when i got it. If it had required this much finesse to operate when new, I would've returned it, gotten my money back and bought something less finicky.

I've got a couple good sets of check weights and I check the scale against them pretty regularly, it's still very accurate and repeatable as long as I do my part, but it has become somewhat of a pain over the years.

I guess it's kind of like driving the same car for years. It starts squeaking a little, but you don't really notice it until one day you're driving along with a friend...

Friend: What's that noise?

You: Huh?

Friend: What's making that squealing sound?

You: WHAT?

Friend: WHERE IN THE HELL IS ALL THAT GODAWFUL NOISE COMING FROM?
IS SOMEONE SKINNING LIVE CATS IN YOUR TRUNK?

You: Oh THAT, yeah I prolly oughtta have Jim check it out next time I get the oil changed...

My scale is marked both Ohaus and RCBS, I think I'm gonna give RCBS a call and see what they say.

 

[dgod]

I have the 5-0-5, have used it exclusively for all accuracy rounds. It has never failed me. I have checked it with the 250 on occasion and it has always been within 0.02gr. I do not have experience with the 10-10, as you said, I've heard good things, but no experience. Suggestion: Use one and check with the other, go back and forth until you are comfortable with one or the other, then the decision is made.

Good Luck
Dan

 

[jmorris]

Anything can be damaged instantly much less something aquired "years ago" 2nd hand.

I can detect a single kernel of powder with my 10-10.



That said my 5-0-5 also has single kernel resoultion, like at the end of this video.



If I want something more repeatable than my charge masters, I set it up like
this.



Not because the 5-0-5 is more repeatable than the 10-10 but because it as repeatable and cheaper.

 

[otisrush]

Thanks for the responses. I really appreciate it.

This morning I did more of a "real world usage" test of the 5-0-5: I put powder in the Uniflow and got it dialed in to a charge I wanted it to dispense. I wanted to see how the scale behaved and how I felt about it as if I was actually going to load; meaning frequent pan on/off, making slight tweaks to the Uniflow, and getting it locked in to dispensing a specific charge.

In all but one dimension I found the 5-0-5 easier to use. I think I'm experiencing what Swampman described: I'd become so accustomed to the quirks of my 10-10 that those quirks had become normal to me. For example, sometimes the scale gets stuck in the pan up position (when a weight is set and the pan is removed so the hanger moves up). I often have to lightly nudge the left side of the beam by the pointer to get it moving.

One takes the good with the bad: The 5-0-5 gives me the sense it moves more freely. As a result, after putting the pan in the hanger, the beam oscillates a number of times and it takes a little more time for me to see where the final resting point will be.

I'm pretty sure the 10-10 is heading off to scale retirement.

Thanks again.

OR

 

[LiveLife]

I'm pretty sure the 10-10 is heading off to scale retirement.

You could be making a grave mistake.

I had both Ohaus 10-10 and RCBS 5-0-5. I liked the 10-10 so much, I bought another one and PIF the 5-0-5.

Both Ohaus 10-10 scales are sensitive enough to detect one piece of 1/4"x1/4" 20 lb copy paper (which weighs around .05 gr) while 5-0-5 was not as sensitive.

If cleaning the triangular knife edges won't zero the scale, I would expose the agate stone "V" blocks and clean any dust/powder particles inside the housing to ensure they are "free-floating" when the knife edges make contact with the "V" notches.

I found the repeatable zero resulted from the knife edges pivoting on the free floating agate bearings. Can you inspect the beam/knife edges to make sure they are not bent and at 90 degrees? FYI, I do the following to clean/tune the scale.

- Remove the bearing covers with a Phillips screwdriver
- Make sure the posts the agate bearings free float on are clean
- Clean the agate bearings, especially the "V" notches
- Re-install the covers
- Clean the knife edges
- Level the bench surface using a bubble level at 90 degrees
- Turn HVAC/vent off and close the window/door to the room as any ambient air movement will affect scale reading/zero
- Place the powder pan on the pan support
- Set both large and micrometer poises to zero
- Lock the micrometer poise with the nylon bolt
- Adjust the leveling foot so the pointer is at the zero line

 

[otisrush]

Thanks bds.

Clean the v notches and posts with alcohol I presume?

How do you recommend checking squareness of the knife edges? (I presume you mean making sure knife edges are perpendicular to the beam.)

Oh....and do your 10-10 scales have this front to back movement? If so, do you do anything to deal with it? Or does that become a non issue once you tune it per your steps above?

 

[LiveLife]

The front to back movement is knife edge beam hitting the agate stone bearing cover plates. The play is normal to allow beam to move freely.

Yes, you can use alcohol to clean the posts and agate stone bearings (especially the "V" notches knife edges pivot on).

Important thing is agate stone bearings "free float" on posts so knife edges can pivot on the "V" notches to produce repeatable zero.

 

[otisrush]

The front to back movement is knife edge beam hitting the agate stone bearing cover plates. The play is normal to allow beam to move freely.

Yes, you can use alcohol to clean the posts and agate stone bearings (especially the "V" notches knife edges pivot on).

Important thing is agate stone bearings "free float" on posts so knife edges can pivot on the "V" notches to produce repeatable zero.

Very interesting. I removed the bearing covers and bearings and cleaned the bearing bases and V-notches, as well as the posts they sit on. I also cleaned the knife edges.

I put it all back together and it was better but it still seemed a little inconsistent. THEN I noticed the rear agate bearing cover was not up tight against the post. The metal cover could be moved. When I'd put the screw in (from the back) I had hit enough resistance I thought the screw was driven all the way home - but it wasn't. I had to apply a good amount of torque but I got it all the way in and got the bearing cover up tight against the post.

Now the performance is MUCH improved. I wish I would have noticed if that back bearing cover was loose before I took it apart. On the one hand I don't remember specifically taking that cover off previously, but I did remember that access to that back cover screw was via a hole in the back. So maybe I removed that cover and didn't get the cover all the way on tight?

In any event, I'll keep using the 10-10. I *want* to like it and use it. I've heard so many good things about them I've always felt fortunate that this guy who sold me his stuff happened to have one.

Thanks for the help bds!

OR