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Need to buy new scale

I have no doubt that my balance beam scale can indicate an additional 1 kernel of powder or even 1/2 kernel for that matter. However, my problem is that even when using a magnifier prism, the graduations on the dial plate are too coarse to easily see whether the beam pointer is at 'zero' or not. Maybe an eyesight problem... I am going to try replacing the dial plate with some laminated graph paper (or similar) first, but otherwise I am considering a GemPro 250.

I don't understand why Sinclair Intl doesn't stock the GemPro 250, as online sellers don't seem to want to ship to the UK :(
 
I recently picked up a usb camera to use with my beam scale... I paid $70. With it, you can see very slight movement on the beam.

I posted some pics of how well it works for this application in this thread - http://forum.accurateshooter.com/index.php/topic,3778847.msg36025128.html#msg36025128

only down side, is you need a computer/monitor near your scale setup. (not a problem for me)


oh, and that paper clip thing... I'm gonna have to try that one too!

This is one of the most informative "scale threads" I've seen on this site... especially for tips and tricks on beam scales.
 
Thanks Wayne! The GD503 is an excellent choice, in fact many of the laboratory scales we used were made by Sarorius although with scales, it seems that the sky is the limit when it comes to cost. We tend to use many of the very expensive Sarorius scales and had a standing contract with the company to do scheduled maintenance and calibration – serious business when you do work that are policed by the FDA. I hope you have the best of luck with the new scale and your competition.

The best way to keep the keep the GemPro 250 tuned is to make sure that you have the proper calibration weights. Here is where it falls a little short as it only comes with a 20 gram calibration weight. The problem is one should always do both the “Sensitivity” and “Linear” calibration before you use the scale, yes even if you have left it on since the last time you use it as this can potentially drift.

To do the “Sensitivity” calibration, the 20 gram calibration standard they supply is used. However, in order to do the “Linear” calibration, you will need the 50 gram calibration standard which they do not supply. My suggestion is to buy it from Granger and it only cost less than $20 - buy it.

The other thing to note is if you are doing the calibration, NEVER touch the calibration weights with your fingers, always use gloves to handle them as your finger oils/salts and the oxidation that they may cause will affect the weights. They are calibration standards and use for such and you must do everything to avoid affecting their weight.
 
jlow,
Informative post, thank you, I am going to implement several new things this year, refine my powder charges to a tighter Tolerance, pointing bullets, and a much better rest setup, we'll see if it all pays off, the proof will be on the target. I never thought about handling the check weights with latex gloves but that makes sense, thanks again.
Wayne.
 
If you add a needle to the beam scale for a pointer do you also need to re-balance that by adding more weight inside the pan?
Or is shifting the level enough?
 
Glad to be of help as I am sure I will get lots of good help there too.

The check weight handling is mostly following consistent good habit, like gun handling. As they say, good habits die easy but bad habits die hard. The slight weight change might only have a small detrimental effect when dealing with 50 gram check weights but we also use small ones which can weight as little as 1 mg and they are basically gone if they are ever touched and so not touching check weights has been kind of pounded into our heads over time – LOL! Good thing!
 
[quote author= link=topic=3780849.msg36037624#msg36037624 date=1329151121]
If you add a needle to the beam scale for a pointer do you also need to re-balance that by adding more weight inside the pan?
Or is shifting the level enough?
[/quote]
in2deep,
Yes, what works good is small diameter solder, first after you glue on the needle for your new pointer level the scale then put you pan on the scale and start adding small pieces of the solder until you reach zero, then take your pan holder apart and add the new weight and your good to go.
Wayne.
 
On this whole how close you can read a beam scale question....I think that it can be argued that when loading for long range that tuning to even tenths of a grain is close enough, BUT that if you are loading 43.4 grains, that only being able to read the scale to .1 is not good enough. You need to know that your extreme spread of weights is within a much smaller range than +-.1, and while the scale on a balance bean scale would be difficult to manufacture with small enough graduations to be able to read to .02, all you really need to be able to do is see that a given quantity of powder that is being weighed falls within the acceptable range.

If you have a scale that will register the addition of one granule of powder, you can simply note the beam deflection for each additional piece, and from that you will have a pretty good idea of how close you are to your desired weight. With a web cam and computer the differences are easy to see, and if it is the width of a line, or half that that you are trying to stay within, it can be seen. That there are no numbers to show these fifths of tenths is not very important. It is like using a gauge. As long as the length of a part is longer than or equal to the minimum, and shorter or equal to the maximum, the part is within tolerance, no numbers needed. I have noticed that sometimes, when we have the ability to resolve to a finer degree than is needed for a particular application, the numbers can take on a life of their own, beyond any practical reason. Even if I had the budget to buy an expensive magnetic force restoration scale, it would do me little good because I would not risk taking it to the range. On the other hand, a tuned balance in a wind box travels well for those few occasions that I need it.
 
For xmas this year I got myself a GD503, and IMO, it's everything it's cracked up to be. Super consistent and stable. Very very little drift. For all intents and purposes, overkill.

For curiosity's sake, I wanted to see how accurate I could be with my Scott Parker tuned Redding beam scale I had been using previously. I measured 10 charges of H4831sc as carefully as I could (throwing and trickling up), and then cross checked them against the GD503.

The results I got were:

50.720
50.745
50.725
50.750
50.715
50.725
50.715
50.720
50.720
50.740

That's a gross spread of .035 gr, and a stddev of .012. A lot better than I expected.

Granted, this is only 10 datapoints, and it was painfully slow as I was really really trying hard to get it perfect. FWIW, I used to have a Chargemaster but sold it before I got the GD503. (I wasn't using it).

-nosualc
 
nosualc said:
That's a gross spread of .035 gr, and a stddev of .012. A lot better than I expected.

Thats excellent results - I think it could be even better with some of the finer powders.
 
BoydAllen said:
On this whole how close you can read a beam scale question....I think that it can be argued that when loading for long range that tuning to even tenths of a grain is close enough, BUT that if you are loading 43.4 grains, that only being able to read the scale to .1 is not good enough. You need to know that your extreme spread of weights is within a much smaller range than +-.1, and while the scale on a balance bean scale would be difficult to manufacture with small enough graduations to be able to read to .02, all you really need to be able to do is see that a given quantity of powder that is being weighed falls within the acceptable range.

If you have a scale that will register the addition of one granule of powder, you can simply note the beam deflection for each additional piece, and from that you will have a pretty good idea of how close you are to your desired weight. With a web cam and computer the differences are easy to see, and if it is the width of a line, or half that that you are trying to stay within, it can be seen. That there are no numbers to show these fifths of tenths is not very important. It is like using a gauge. As long as the length of a part is longer than or equal to the minimum, and shorter or equal to the maximum, the part is within tolerance, no numbers needed. I have noticed that sometimes, when we have the ability to resolve to a finer degree than is needed for a particular application, the numbers can take on a life of their own, beyond any practical reason. Even if I had the budget to buy an expensive magnetic force restoration scale, it would do me little good because I would not risk taking it to the range. On the other hand, a tuned balance in a wind box travels well for those few occasions that I need it.

Boyd,
That is why I keep you around my friend,..........you make perfect writen sense of what I was trying to convey :D ;) Thank you my friend.


nosualc said:
For xmas this year I got myself a GD503, and IMO, it's everything it's cracked up to be. Super consistent and stable. Very very little drift. For all intents and purposes, overkill.

For curiosity's sake, I wanted to see how accurate I could be with my Scott Parker tuned Redding beam scale I had been using previously. I measured 10 charges of H4831sc as carefully as I could (throwing and trickling up), and then cross checked them against the GD503.

The results I got were:

50.720
50.745
50.725
50.750
50.715
50.725
50.715
50.720
50.720
50.740

That's a gross spread of .035 gr, and a stddev of .012. A lot better than I expected.

Granted, this is only 10 datapoints, and it was painfully slow as I was really really trying hard to get it perfect. FWIW, I used to have a Chargemaster but sold it before I got the GD503. (I wasn't using it).

-nosualc

nosualc,
Thank you for taking the time to do the research, the facts are in and it is spot on what I was saying. I understand that the 503 is much faster,....it should be for an additional $850 or so over the balance! if I owned a 503 I don't think I would even try to tighten that up at all,...not true I am anal about such things I would probably be there with a exacto knife shaving a kernal of powder ::) to get 50.700 on each load, heck I am batty enough now!! Seriously thank you for the comparison test.
Wayne.
 
I'm a big beleaver in balance beam scales, I know in this world electronics something mechanical must be out dated but when it comes to rock solid repeatability a mechanical balance beam is king.

This is my old scale, a Gen 1 Prometheus, I use the USB camera trick with it
dscf0068k.jpg

1 kernal resolution is no problem what so ever, the scale is a two handed operation left hand holds the case in the funnel, right hand actuates the Uniflo and trickler, I can charge a case every 20-25 seconds.

This is my new Gen 2 Prometheus, it will charge a case every 12-14 seconds, its 3-5 times more sensitive than the Gen 1, and uses a electronic trickling system with 2 photo eyes running the trickler, or basically its a balance beam ChargeMaster
imagedis.jpg

I went to Brand Cole house to pick it up, he showed me how he makes 85% of it in his shop, how to use the machine and maintain it, he had a 15k Lab scale he uses to verify the accuracy of his machine, over the course of dispensing 40gr charges of varget the ES was .006gr when the needles lines up perfectly, because powder varies in size that is not the norm nor will it ever be with any scale. I got home and made me a stand for it to sit on, loaded 40 rounds, I can't seat a bullet faster than it can dispence the next charge, went to the range, while shooting thru my CED M2 my 20 Gen 1 rounds had a SD of 6 and ES of 9, not bad at all in my book but, the 20 from the Gen 2 had a SD 3 and ES of 5, for me its about the speed, the super accuracy is a plus, less time reloading means more time shooting.
 
My Gen 1 and a Gen 2 comparison
http://www.youtube.com/watch?v=2sqNcs-uWzY
My Gen 2 has upgraded electronic trickling system v the one in the vid
 
I went from a $100 RCBS Rangemaster 750 with .1 resolution to an Acculab VIC123 with .02 resolution and my ESs and SDs shrank immediately.

Apparently the variances hidden by .1 resolution are big "enough".
IE: is that 32.2 closer to 32.20 or 32.29?
 
Cheapest I have found was scalemans.com $949.99 I would think jaychris would possibly know, I am surprised he has not chimed in.
Wayne.
 
bozo699 said:
Cheapest I have found was scalemans.com $949.99 I would think jaychris would possibly know, I am surprised he has not chimed in.
Wayne.

Looks like $995.01 now....they are prob watching our threads..LOL!
 
wow... that thing is expensive!

I would never think that it would be worth the cost to buy something like that for reloading. However, the testing that brian427cobra did shows some interesting numbers over the chronograph... an SD of 3 and ES of 5 is almost unheard of. I'm not going to ask brian427cobra to burn up components and barrels to do a large test, but it would be interesting to see the results of a large sample...
 

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