Scott Parker's scale tuning method

[Chiquita]

@Mr. Zorg how does your scale work now compare to before?

What do you compare your scale to or how do you test it and see if the juice was worth the squeeze?

 

[Texas10]

Seizing upon some of the things I learned in my recent conversation with Scott, I removed the magnets from my RCBS 10-10 Ohaus made scale to see if sensitivity would improve. The problem I am having is that the pointer rises up to zero as I trickle up the charge, and then tends to stick there which can result in an over charge by several tenths of a grain. Scott attributes this tendency to a "hot spot" or magnetized portion of the beam becoming magnetically locked to the base magnets.

Previous attempts to fix sensitivity had been only somewhat successful, cleaning the beds and adding pencil lead scrapings, sharpening the knives all helped but the issue continued to reappear.

With the magnets removed, the tendency to oscillate increased, but sensitivity also increased. A couple of kernels of powder would move the pointer. Oscillation wasn't unmanageable, only taking a few extra seconds of waiting for the beam to settle. Still though I felt it wasn't consistent.

Then I removed and cleaned the beds, inspecting under 10X magnification and found the "V" notch in one bed to have a slight flat spot unevenly distributed across the V, a sign of localized wear.

I reversed and reinstalled that bed along with the other. Then scraped pencil lead into the beds.

I also inspected the knives under 10X and found they also needed a more thorough sharpening. I used my diamond stone to get a clean edge.

Once reassembled the tendency to oscillate increased dramatically, and could take as long as 30 seconds to settle down. So clearly I had reduced the friction in the pivot point. I'll try reinstalling the magnets and see how that affects the operation.

Just to clarify, I sent a recently purchased Ohaus scale to Scott for calibration. I am currently using an RCBS Ohaus made scale that has not been "accurized" by Scott and that is the one I am referring to above.

UPDATE: I was WAY off on the oscillation time without the magnetic dampeners. I clocked it a 3:45 before the amount of oscillation was too small for me to clearly see. That was from a full deflection start.

I put the magnets back in and was amazed to find that the scale now exhibits good dampening as well as excellent sensitivity. Just two or three kernels of Varget will move the needle a very noticable amount with no tendency to stick around zero.

My conclusion is that the knives and beds were the source of the problems. My thanks to Sparker for the suggestions. Still looking forward to the new scale, however.

 

[Bc'z]

Seizing upon some of the things I learned in my recent conversation with Scott, I removed the magnets from my RCBS 10-10 Ohaus made scale to see if sensitivity would improve. The problem I am having is that the pointer rises up to zero as I trickle up the charge, and then tends to stick there which can result in an over charge by several tenths of a grain. Scott attributes this tendency to a "hot spot" or magnetized portion of the beam becoming magnetically locked to the base magnets.

Previous attempts to fix sensitivity had been only somewhat successful, cleaning the beds and adding pencil lead scrapings, sharpening the knives all helped but the issue continued to reappear.

With the magnets removed, the tendency to oscillate increased, but sensitivity also increased. A couple of kernels of powder would move the pointer. Oscillation wasn't unmanageable, only taking a few extra seconds of waiting for the beam to settle. Still though I felt it wasn't consistent.

Then I removed and cleaned the beds, inspecting under 10X magnification and found the "V" notch in one bed to have a slight flat spot unevenly distributed across the V, a sign of localized wear.

I reversed and reinstalled that bed along with the other. Then scraped pencil lead into the beds.

I also inspected the knives under 10X and found they also needed a more thorough sharpening. I used my diamond stone to get a clean edge.

Once reassembled the tendency to oscillate increased dramatically, and could take as long as 30 seconds to settle down. So clearly I had reduced the friction in the pivot point. I'll try reinstalling the magnets and see how that affects the operation.

Just to clarify, I sent a recently purchased Ohaus scale to Scott for calibration. I am currently using an RCBS Ohaus made scale that has not been "accurized" by Scott and that is the one I am referring to above.

On my parker tuned D5 there is a small square of electrical tape centered on the back of dampener blade, I presume to weaken the effects of the magnetic field.
Thought this might help.

 

[BoydAllen]

I do not think that some shooters really understand how the damper works. The copper blade and scale beam are not attracted by the magnets at all. When I conductor (the copper damping blade) passes through a magnetic field, eddy currents of electricity are created within the conductor, as well as a magnetic field that is in opposition to the field acting on the conductor. It is this magnetic counter force that does the damping. It is ONLY there if the conductor is moving, so when the beam stops, wherever it stops, the magnet is not holding it there. I believe that what you are seeing is an issue with the knife edges. I have successfully tuned several scales for myself and helped others with theirs. I make no claims, and have never charged any one, but my scales reliably return to zero and are much more sensitive than when new. That is all that I need. If they are off a tenth of so from an absolute standard, as long as I continue to use the same scale, it does not matter to me.

 

[JFrank]

On my parker tuned D5 there is a small square of electrical tape centered on the back of dampener blade, I presume to weaken the effects of the magnetic field.
Thought this might help.

Interesting, I wonder if Scotty put that on.

 

[M-61]

I do not think that some shooters really understand how the damper works. The copper blade and scale beam are not attracted by the magnets at all. When I conductor (the copper damping blade) passes through a magnetic field, eddy currents of electricity are created within the conductor, as well as a magnetic field that is in opposition to the field acting on the conductor. It is this magnetic counter force that does the damping. It is ONLY there if the conductor is moving, so when the beam stops, wherever it stops, the magnet is not holding it there.

I'm one that does not understand what's happening. Even though this sounds like backwoods gypsy mysticism I do KNOW it not only occurs but works. This YouTube clip I think gives a decent explanation.

After a bit more than one minute you get a good idea of what's happening.
This has nothing to do with Parkers customer service.

 

[Bc'z]

Interesting, I wonder if Scotty put that on.

I would venture to say yes.
Tape is only on 1 side of the vane.
I suppose a guy could put a piece on the other side as well to really soften the dampening.
May need to add a lil scotch tape to pan for counter weight.

 

[sparker]

I don’t remember putting a piece of electrical tape on any scale. Perhaps it was there to start with and I didn’t notice it. Strange that I wouldn’t have seen it as I check the dampening vanes for any signs of movement.

Scott Parker

 

[Bc'z]

I don’t remember putting a piece of electrical tape on any scale. Perhaps it was there to start with and I didn’t notice it. Strange that I wouldn’t have seen it as I check the dampening vanes for any signs of movement.

Scott Parker

She's accurate to the kernel, amazing at the sensitivity to a few flakes of ball powder also.
Scale was gifted to me about a year ago or so.
I need to check it next to the 10-10 in the background.

 

[Texas10]

Probably a previous attempt to correct a small amount of linear error when using check weights.

 

[Mr. Zorg]

@Mr. Zorg how does your scale work now compare to before?

What do you compare your scale to or how do you test it and see if the juice was worth the squeeze?

I haven't futzed with it yet, I bought a vintage Ohaus 10-10 as well, thankfully since my 10-0-5 was lodging elsewhere for 3 months. Been busy with some other stuff.

 

[sparker]

I do not think that some shooters really understand how the damper works. The copper blade and scale beam are not attracted by the magnets at all. When I conductor (the copper damping blade) passes through a magnetic field, eddy currents of electricity are created within the conductor, as well as a magnetic field that is in opposition to the field acting on the conductor. It is this magnetic counter force that does the damping. It is ONLY there if the conductor is moving, so when the beam stops, wherever it stops, the magnet is not holding it there. I believe that what you are seeing is an issue with the knife edges. I have successfully tuned several scales for myself and helped others with theirs. I make no claims, and have never charged any one, but my scales reliably return to zero and are much more sensitive than when new. That is all that I need. If they are off a tenth of so from an absolute standard, as long as I continue to use the same scale, it does not matter to me.

This is all quite true if one is dealing with pure Cu and pure Al. However, the beams are not made of materials quite so pure. I have experienced magnetic hot spots on beams time and time again. It’s not an issue with the pivot knives. Ask me how I know...

 

[BoydAllen]

This is all quite true if one is dealing with pure Cu and pure Al. However, the beams are not made of materials quite so pure. I have experienced magnetic hot spots on beams time and time again. It’s not an issue with the pivot knives. Ask me how I know...

Thanks for the info. I guess that I have just been lucky. Of course you have dealt with a large number of scales and I have fiddled with relatively few.

 

[M-61]

I suppose a guy could put a piece on the other side as well to really soften the dampening.

This will not reduce the Eddy effect.

 

[Bc'z]

This will not reduce the Eddy effect.

I don't know.
Only testing would tell.
My thinking is rubber is not a conductor of current, having 2 layers would help break up the pull of the magnetic field.
For S&G's I'll play with it later using check weights and a counter to see how long it takes to quit swinging.

 

[Bc'z]

This will not reduce the Eddy effect.

So I didn't have electrical tape, I substituted with vinyl fine line painters tape.
Counted 1.5 swings until settling on "0"
With and without additional tape.
Now I wonder what the hell it's there for.
Both the D5 and 10-10 resolve a 50gr check weight to "0".

 

[M-61]

So I didn't have electrical tape, I substituted with vinyl fine line painters tape.
Counted 1.5 swings until settling on "0"
With and without additional tape.
Now I wonder what the hell it's there for.
Both the D5 and 10-10 resolve a 50gr check weight to "0".

Glad you got to test it.
The whole set up is a mystery to me except I know it exists.
I wound up reading how it is used on some trains and some roller coasters. Talk about getting side-tracked!

 

[chop house]

The whole set up is a mystery to me except I know it exists.

wanna see something hilarious watch a bunch of nerdy engineering students in undergrad magnetics courses wrapping their hand around imaginary conductors to see which way their thumb points...

oh, wait....

that was me.

 

[M-61]

I think:
The first scale I owned had a small paddle that was part of the beam and protruded into a cast in reservoir. The reservoir you filled with oil. I wonder whether that's really true or I'm confusing this. Anyway it sure was simple to see why the scale stopped oscillating unlike this Eddy effect. If it is true I guess I really didn't move the scale around with that oil.
Be nice to have someone chime in and say they remember that type. If not I guess I'm really slipping. (maybe into an eddy)

 

[Mark W]

I think:
The first scale I owned had a small paddle that was part of the beam and protruded into a cast in reservoir. The reservoir you filled with oil. I wonder whether that's really true or I'm confusing this. Anyway it sure was simple to see why the scale stopped oscillating unlike this Eddy effect. If it is true I guess I really didn't move the scale around with that oil.
Be nice to have someone chime in and say they remember that type. If not I guess I'm really slipping. (maybe into an eddy)

I still have an old oil dampend Redding No. 1 that i bought and used while I waited on my tuned scale from Mr Parker.