Digital Scale issues....are they all alike?

[Prowler53]

I have a Frankford Arsinal DS-750 and I had some problems that made me switch back to my beam scale today. This is not a new issue, but I spent quite a bit of time today loading up test rounds with different powders/bullets. I've had to reset the zero on the scale or sometimes even shut off the power and re-set every 5 or so weight checks.

The weight of the empty pan is 127.9 grains, and sometimes I will weigh a charge and drop it into the case, return the pan to the scale and it will read 127.8 or 128.0 or even 127.7. Usually off +/- .1. Occasionally I will notice it reads 127.7 and gradually sneaks back up to the correct weight but I need to wait 5 seconds or so for it to correct itself, and other times it will not correct itself at all.

The scale seems to be slow calculating the weight which makes it hard to trickle charge. Add a little powder and weigh to see if it goes up another tenth....Nope, add a little more......Nope, add just a wee bit more....Jumps .2 - .3 grains at once.

Do I need a new scale? or am I going to have some of the same issues with any digital I buy?

 

[Hartkopf]

You just described my Lyman scale. I found mine to be way better if the temperature is at a comfortable temperature, like 68 to 75 degrees. Air flow needs to be at zero. The shop doors must be shut and even then if the wind is flexing the door (causing pressure), it will throw the scale off. The scale needs to be on an isolated bench with no vibration. If it’s plugged into a wall socket, don’t run anything else off of that outlet. And it needs to be turned on to warm up for at least 30 minutes. Other than that it’s low maintenance.

 

[PWC]

My "gold standard" is my Pacific powder balance with calibration weights.

I have an inexpensive battery ppwered Lyman Pocket scale. If I dp my part they are the same, at most .002 difference. Acceptable for my needs.

I have found: obviously use fresh batteries, calm air, no flourescent lights, and most of all temperature normalization. I keep the scale in the house, but reload in the garage. At least 2 hrs before I begin to reload, I put the scale where it will be used. Not necessary to turn it on, as it will shut itself off if not used.

The first scale I bought wouldn't cal when I hot it home. Back for the xchange. I couldn't check it right away. Several bours later, when I did, it was perfect. It appears it is like my astro telescope; the mirror must be temp stabalized to use.

 

[Jesse Heywood]

No, they are not all alike. First read this thread. It is long, but full of information.
https://www.thehighroad.org/index.p...mation-busting-digital-scale-accuracy.759750/

I have had a RCBS Range Master 750 for just over 10 years. It settles in less than 5 seconds. Had a problem a few weeks back, which was due to powder dust inside the scale. Before I had the problem I resolved I ordered the Gemini recommended in the thread. It is a very accurate (.001 gn) and fast scale. But it is too small for my big hands.

 

[Prowler53]

It's battery powered and has auto shutoff when not in use, so warming it up is not an option. I always have my door closed but I do have a draw fan in the window which is always running when I'm in here. I'll have to shut it off and see if that helps....Thanks for the tips!

 

[Prowler53]

I'll check that out Jesse...Thank you!

 

[greyling22]

my FA750 scale wanders a little too. it seems to do better if you can turn it on, then let it warm up. of course, it wants to turn off, so you have to poke it every minute or so while you set up the rest of your stuff.

 

[Patocazador]

My PACT has given me good service for over 15 years, plus their C.S. is fantastic.

 

[LeftyTSGC]

I use a GemPro 250, yes all electronics of this caliber are affected by temp, vibrations, air, and most of all static electricity. I have had issues in the past and now I have put a ground on it, (copper wire ) and I don't have the same issues. Also you have to let them warm up a bit if it has been turned off for a while. At least this is what has worked for me. You could also put try to put the wire on the negative terminal in the battery compartment, but mine worked as stated.

leftytsgc

 

[brutus51]

I use a Lyman model as a double check, my balance beam is what i believe in.

 

[swg1]

If I'm not using an automatic powder dispenser I always use a beam scale when trickling in the last granules of powder. It was always easier for me to see the beam swing into position than wait for a digital scale.

The digital scale gets more of a workout checking cast bullets for discrepancies.

 

[Obturation]

I won't spend a ton on a digital scale, I've had good success but you must consider it's limitations. If I'm loading a max charge I don't trust a digital, if I have some wiggle room (.2 +/- grains) and not loading for maximum accuracy I don't worry about it. I do check any scale with a check weight before use. I've had goofy readings and as @Jesse Heywood had- powder under the platform causing fluctuation, blew it out with compressed air and things were back to normal. Also try fresh batteries if things are getting weird.

 

[PWC]

It's battery powered and has auto shutoff when not in use, so warming it up is not an option. I always have my door closed but I do have a draw fan in the window which is always running when I'm in here. I'll have to shut it off and see if that helps....Thanks for the tips!

Can't be hotter phan Phoenix (xpecting first 100 degree day next week)

The scale just needs to aclimitize itself to its surroundings. Load cell coming from AC to garage will be inaccurate til it settles.

 

[bersaguy]

My Hornady digital scale does much the same thing. Bought a beam scale to check it against. Turns out it's not bad, but when it reads low and then sneaks back up a tenth after 10 or 15 seconds...kinda drives me nuts. Fresh batteries, still air, constant temperature and a solid bench help.

 

[bluetopper]

I use two battery powered digital jewelers scales I bought off ebay. I'm happy with them and they were inexpensive.

 

[jmorris]

All digital scales are alike in the same way all aircraft are alike. They, for the most part, rely on the same principals in order to function. The methods used to accomplish the end goal is where the difference is and you don't always get what you pay for but you always pay for what you get.

I have really good and really cheap digital scales and the same for mechanical ones.

My Chargemasters have an auto zero "feature" that I really don't like because things can change without me knowing.



I also have old used and fairly cheap scales, that with the addition of a <$20 photo electric switch are quite repeatable.

 

[Texas10mm]

I have an inexpensive battery ppwered Lyman Pocket scale. If I dp my part they are the same, at most .002 difference. Acceptable for my needs.

That's one hell of a beam scale you've got if it has the precision to weigh to 0.002 gr.

 

[rfwobbly]

My Chargemasters have an auto zero "feature" that I really don't like because things can change without me knowing.

► Few people stop to truly consider how a digital scale actually gets from weight to a digital readout.

In truth, ALL digital scales need software to convert the electrical resistance measurements taken through the strain gauge, and convert those into electrical signals that power the electronic display. You may see some "flutter" while taking a weight reading, but have you ever considered why there's no flutter at Zero ? It's because the software is massaging the numbers. That is to say, in order to give the appearance of being "rock solid" the software is actually averaging an unknown number of readings before it decides on a number to display. Or maybe the software understands that the scale has settled down and is reading numbers within a certain range, and simply picks one to display. Who knows ?

So the big issue with digital scales is that the user is not in charge of the software. The owner doesn't get to pick the number of readings taken before a numeral is displayed on the screen. The user is never given any clue as to what estimates are made or what mathematical allowances the software uses. But rest assured.... mathematical adjustments ARE being made.

So even within a scale that's operating correctly, changes are being made without you knowing !!


https://en.wikipedia.org/wiki/Strain_gauge

 

[PWC]

That's one hell of a beam scale you've got if it has the precision to weigh to 0.002 gr.

It's not a scale it is a balance. Once set up, it will respond to single kernal of 4064.

If it's zeroed with cal weights, then
powder added, the Lyman pocket scale reads w/in .002 of the balance.

 

[jmorris]

So even within a scale that's operating correctly, changes are being made without you knowing !!

To the end user, I agree, to the person that wrote the code that interprets the values returned from the load cell, they know what the values are doing vs the ones displayed.

I learned quite a bit on the subject on this project.



The way I wrote the program for the above, There is a "zero" button, like many other digital scales I use. Those chargemasters above will zero themselves out, with obvious weight on them, to hide the changing values from a scale warming up. That I do not like.

 

[jmorris]

That's one hell of a beam scale you've got if it has the precision to weigh to 0.002 gr.

He didn't say .002 grains, rather "precision to .002", without any unit of measure.

.002 grams is .03 grains and a single kernel of extruded powder can be in the .02 grains area. Even the A&D balance in the 2nd video of #16 can catch that. As can the old 505 with the photo electric switch at the end of the first video in the same post.

Most cheap digital scales don't have that resolution, so their data is truncated at the tenth of a grain or hundredth of a gram.

 

[Typetwelve]

I'll say this...when it comes to digital scales, I don't fully trust them. I've had an expensive digital scale (brand doesn't matter), and a cheap one (also, brand doesn't matter). Both drift. The expensive one drifted in a super subtle manner that was near impossible to detect, the cheap one drifts in a manner in which I can easily tell and correct the problem. I've tried all kinds of voodoo from all the suggestions I've read online and in the end...yup, they drift.

I kept the cheap one as it is predictable and cross reference it with a trusted bar scale.

If there is indeed some scale that doesn't drift...or some troubleshooting tactic to keep them from doing it, I've lost my patience enough to try anymore. I'm going to stick with my predictably unpredictable cheap digital and my trusted bar scale.

 

[BBarn]

My FA DS-750 and Lyman Pocket Touch behave much the same way, with the zero slowly drifting and requiring frequent re-zeroing.

My National Metallic 1600 is much better behaved, seems fairly stable, and inspires greater confidence. I also like that it comes with an AC adapter and doesn't shut off or go to sleep as long as it's plugged in.

 

[mcb]

I have a simple old RCBS 750 Rangemaster digital scale. Its a simple scale. I have found that if I know I am going to be using it I try to get it turned on hours if not a whole day or before I am going to use it. Having it on a long time before use seems to eliminate nearly all my drift problems. Calibration is easy so I always do that before use and then at moderate intervals I use weights to check the calibration. As long as I do this I am pretty trusting of my scale.

 

[Laphroaig]

Ya, digital scales can have a mind of their own sometimes, to the point it makes you a little crazy. All digital scales depend on some sort of load cell. For the size and costs of most of the scales we use it's amazing that they work at all.

Currently I have a Gempro 250. I use a slightly heavier pan now (one of the combo pan/funnel deals) and I think the scale works better with it. I loaded 10 rounds with thrown charges the other day, and checked the weights with the Gempro before I seated the bullets. I then double checked the weights. Four agreed perfectly, 3 were within.02 gr., 2 within .04, and one was within .06. I think that is pretty good precision, all within .1 gr.