Chargemaster floating zero WTF

[357Max]

I have a deposit down on a V4.

Meanwhile I'm stuck with this CM till Feb or March. Trying to figure out why the zero doesn't hold well on the Chargemaster during a reloading session. The zero will shift .1 - .2gr

This is after leaving the unit on for 30+ minutes before zeroing & starting to drop charges.
I also decided to try a test to see how many kernels it takes to make a .1gr change and now I'm scratching my head.

Watch the video & please explain this???? Now to be fair if I drop 20 - 30+ grains & then trickle It's not doing what is shown or at least not near as bad.
What I think is happening is when I put the 419 scoop back on the platen it will float itself to zero just a little & this becomes cumulative when loading say 200 rounds.

 

[Holliday]

I thought I read somewhere that at close to “pan weight” the scale will keep trying to zero itself. Basically the scale thinks the pan is empty and is compensating for thermal drift etc. In short, I don’t think it is designed to be run like a normal scale without using the dispenser.

Having said that, I have used mine to measure case volume water weight and it seems to do ok but I have nothing to compare it to. If those are in error that could explain some quick load issues I have been having......

 

[357Max]

Bumping this thread. Anyone from RCBS on this forum??

If this is a feature, it sucks Squirrel nuts & I'd like to disable it if possible.

I'm stuck with it till late Feb before my V4 ships.

Thanks

 

[Doom]

If you watch the zero indicator symbol in the upper left you will see the scale is rezeroing as you add the kernels. At least that appears to be the case. It seems to be interpreting the small weight shift as zero drift. I’ve done a fair amount of research and no one seems to know for sure. This should not cause a problem in normal operation.

 

[hafejd30]

Mine does the same. It thinks it’s starting empty. Mine zeros out on an empty pan then throws the charge on its own after zeroing. Will not cause issues with operation from what I’ve seen. Doesn’t wander around when loaded or weighing something like bullets etc

I throw the empty pan on. Scale zeroes then throws powder.

My ceiling fan stays off when charging or the air movement from that causes issues. Also if I hold the pan slightly above the scale plate it will go nuts. Maybe friction idk

But I haven’t had issues with it wondering with weight in the pan. I tested mine against a rcbs 505 balance beam scale and it was good to go

Use it for powder (obviously) and sorting bullets all the time

 

[straightshooter1]

Bumping this thread. Anyone from RCBS on this forum??

If this is a feature, it sucks Squirrel nuts & I'd like to disable it if possible.

I'm stuck with it till late Feb before my V4 ships.

Thanks

I went to powering my CM with DC only and having no other electrical devices near by (e.g. cell phone, computer, no florescent lighting and not AC or heating going on to move the air). Doing this pretty much solved my drifting issues.

The power pack I use is like this (a different brand):

 

[acudaowner]

if it doesn't work send it back let the company deal with it . And away go your troubles down the drain, roto rooter . If you got the passion for fashion , and you got the cravings for savings then take the wheel of your automobile and head on down to Ideal . lol

 

[PinesAndProjectiles]

Does it have anything to do with your pan weighing 630 grains?

Mine weighs 147.5 and doesn’t do this.

I’m wondering if on the upper end of the limit the scale isn’t as accurate?

 

[blksno]

I have 3 and after a few hours warmed up yesterday...I decided to calibrate them all using the same weights. (instead of their own weights)
I was surprised to see one pan checked on each scale, vary by more than .5gr across all three scales.

I have one set up for a specific powder, and I have one pan marked with it's weight and set to use that scale...so at least the charge is consistent each time. It would be vastly different if I were to use a pan on a different scale. Mildly frustrating. But by having the pan weight marked, it's easy to see if anything wanders. If it does, I just recalibrate and verify based on the pan weight.

 

[Holliday]

I went to powering my CM with DC only and having no other electrical devices near by (e.g. cell phone, computer, no florescent lighting and not AC or heating going on to move the air). Doing this pretty much solved my drifting issues.

The power pack I use is like this (a different brand):

View attachment 7755855

How does this hook up and what is the output of this power-pack? Thx

 

[straightshooter1]

How does this hook up and what is the output of this power-pack? Thx

"The one I use has an output of DC 5V at 2.4A and has a battery capacity of 10,000 Milliamp Hours." (edit correction for misinformation) The one I use for my CM has an output of DC12V at 3V having a battery capacity of 6,000 mAh. The other I use it on trips to charge my phones, a backup for my laptop, powers my rifle barrel cooler, etc., etc. When I'm using it for my CM, it hardly drains much power when charging 50-100 cases as I typically do.

For output, you plug in a USB cable into the power unit with whatever male end needed, like for the ChargeMaster it's a 5.5 x 2.1mm adapter.

 

[Holliday]

The one I use has an output of DC 5V at 2.4A and has a battery capacity of 10,000 Milliamp Hours. I use it on trips to charge my phones, a backup for my laptop, powers my rifle barrel cooler, powers my ChargeMaster 1500, etc., etc. When I'm using it for my CM, it hardly drains much power when charging 50-100 cases as I typically do.

For output, you plug in a USB cable into the power unit with whatever male end needed, like for the ChargeMaster it's a 5.5 x 2.1mm adapter.

Thanks man! So if I understand correctly, the Chargemaster will run on 5v at 2.4A? And this is a more stabile power source than the wall adapter?

 

[Hollywood 6mm]

Something else you can try is a power conditioner. I have one mounted on my bench that's designed for server racks, and it definitely will help with stability on scales - no matter what kind.

 

[straightshooter1]

Thanks man! So if I understand correctly, the Chargemaster will run on 5v at 2.4A? And this is a more stabile power source than the wall adapter?

Yes.

 

[salks]

Put a dryer sheet under it. Changed my world.

 

[Alpine 338]

Along with what's mentioned above about interference from cell phones, florescent lights, etc. Static is another thing that will cause scales to drift. Get rid of those plastic reloading trays, plastic funnels, or anything else that's plastic on the reloading bench. Once you do that, you'll see a big improvement with stability. The black plastic powder bottles and jugs are Ok, as they are a special plastic that's made to eliminate static.

Also, don't wear polyester or synthetic blend clothing when reloading, as that induces static. 100% Cotton is the way to go.

 

[Alpine 338]

I also use a simple choke on the power cord between the wall wart and the scale. Helps eliminate any EMI/RFI induced noise from the power cord.

Here's a sample:

 

[Holliday]

Interesting to say the least given that the adapter output is 12v.

 

[Holliday]

Something else you can try is a power conditioner. I have one mounted on my bench that's designed for server racks, and it definitely will help with stability on scales - no matter what kind.

Can you recommend one?

 

[2aBaC̶a̶]

Can you explain how this causes a drift during normal use?

I can see if some loose kernals fall into the pan when you place it. And then the machine drops your charge on top of it. But then next time it will zero back to empty pan weight. So your back to zero. Plus you can clearly see if its off from pan weight. Mine wont auto throw if it doesnt reach zero.

 

[Taylorbok]

I thought I read somewhere that at close to “pan weight” the scale will keep trying to zero itself. Basically the scale thinks the pan is empty and is compensating for thermal drift etc. In short, I don’t think it is designed to be run like a normal scale without using the dispenser.

This is my opinion on the matter as well. Scale is compensating on it's own. You could try and call RCBS and see what they say.
I've got a V4 on order also

 

[straightshooter1]

Interesting to say the least given that the adapter output is 12v.

View attachment 7756292

I apologize!!! Apparently, a senior moment for me. The one I use for my CM indeed has an DC output of12V 3A. This is it:

 

[Holliday]

Can you explain how this causes a drift during normal use?

I can see if some loose kernals fall into the pan when you place it. And then the machine drops your charge on top of it. But then next time it will zero back to empty pan weight. So your back to zero. Plus you can clearly see if its off from pan weight. Mine wont auto throw if it doesnt reach zero.

If by “this” you mean my post on it trying to re-zero, the short answer is I haven’t a clue.

My “speculation” is that it is compensating for the load cell drifting as it warms up. There is no question that I have witnessed a discrepancy in pan weight from cold to warm. This is why I always pre-warm the load cell by turning it on at least 30 mins before use. I calibrate at that time before every use.

 

[Holliday]

I apologize!!! Apparently, a senior moment for me. The one I use for my CH indeed has an DC output of12V 3A. This is it:

No worries, this is why I ask the stupid questions .

Thanks for the link! Just what I was looking for!

 

[Holliday]

Also, don't wear polyester or synthetic blend clothing when reloading, as that induces static. 100% Cotton is the way to go.

I wear crocs around the house so I pop them off and touch a water pipe before going to the bench. Crocs are notorious for building up static. Just ask Shelby-Kitten who occasionally gets a bolt to the nose…..

I also use my phone to snap photos-of-record while I set up. I always place it on airplane mode while using the scale and set it at least 3’ away when not in use.

 

[2aBaC̶a̶]

If by “this” you mean my post on it trying to re-zero, the short answer is I haven’t a clue.

My “speculation” is that it is compensating for the load cell drifting as it warms up. There is no question that I have witnessed a discrepancy in pan weight from cold to warm. This is why I always pre-warm the load cell by turning it on at least 30 mins before use. I calibrate at that time before every use.

Im not seeing where the problem lies.

The machine has a self zero feature. Imo, its a good feature. Lets say a few grains get stuck to the bottom of your pan. The scale will compensate for that, re-zero and drop your intended charge.

If you think its broken, ill take it.

 

[Holliday]

Im not seeing where the problem lies.



If you think its broken, ill take it.

Unfreakin believable…….

 

[Doom]

The response you see is auto zero (auto tare). To measure what you are seeking do the following:

Calibrate as usual.
Zero
Place the 50 gram weight in the pan and switch to weigh in grams.
(Assume display reads 50.00 g)
trickle in .03 g of powder (50.03g)
0.03 g is .463 grains
count the number of kernels.
divide the number of kernels by .463 (or .4629708) to get kernels per grain.
Multiply kernels per grain times 0.1 to get kernels per 0.1 grain.

You can weigh less than 0.03 g but due to resolution issues this reduces errors since you are using the last digit of the display. By using the 50 g weight you are clear of zero so the auto zero function should be out of the picture. Do not try switching and using grains because your 50 gram wt actually weighs 771.6179gn. If you weigh to see .1 grain increment you will have added only ~0.08 grains.

 

[Taylorbok]

A work around could be to zero your scale with your pan off then put the pan back on and then add what ever charge you want to that weight. gonna involve some math but allows you to do what you want

 

[Doom]

A work around could be to zero your scale with your pan off then put the pan back on and then add what ever charge you want to that weight. gonna involve some math but allows you to do what you want

You don’t know the true pan weight. That is why you use a calibration weight.

 

[357Max]

The response you see is auto zero (auto tare). To measure what you are seeking do the following:

Calibrate as usual.
Zero
Place the 50 gram weight in the pan and switch to weigh in grams.
(Assume display reads 50.00 g)
trickle in .03 g of powder (50.03g)
0.03 g is .463 grains
count the number of kernels.
divide the number of kernels by .463 (or .4629708) to get kernels per grain.
Multiply kernels per grain times 0.1 to get kernels per 0.1 grain.

You can weigh less than 0.03 g but due to resolution issues this reduces errors since you are using the last digit of the display. By using the 50 g weight you are clear of zero so the auto zero function should be out of the picture. Do not try switching and using grains because your 50 gram wt actually weighs 771.6179gn. If you weigh to see .1 grain increment you will have added only ~0.08 grains.

@Doom - Thanks I've got the CM warming up now. Going to try this as well as zero + pan then drop .03

I'm going to skip all the line filters, rubber slippers, and such.

Still I'm aggravated. Whats the point of calibrating if this damn thing just disregards the calibration as shown in the video?
At that point it's not truly measuring weight, but a differential from it's floated zero to XXX # of grains added.

Yes it's effective & functions, but it's functioning as a self zeroing comparator & I've never seen anyone point that fact out.

I suspect the weight of the offset handle on the 419 pan might be causing it to want to float the zero before auto throwing.

The 419 pan weighs exactly 630gr & when loading 100+ rounds I would notice the scale reading 630, then 630.1, then 630.2 etc while dumping charges. I thought it was floating even after a 30 min warm up, but it doesn't change at all even after 3-4 hrs if not in use.

 

[Taylorbok]

You don’t know the true pan weight. That is why you use a calibration weight.

I'm not saying to calibrate the scale with the pan, calibrate as normal but zero it with the pan off. then when you put the pan on it will read the pan weight and not try to re-zero itself then he can trickle in what ever weight he wants.

 

[Doom]

The auto zero/auto tare is a standard technique that employs standard weighing techniques going back to spring scales. All scales are subject to the effects of temperature, hysteresis, and creep. Electronic scales also have issues with operating temperature drift. I’m willing to bet your grandmother or great grandmother made sure the butcher’s scale read zero before anything went on the scale, every time!

When weighing, requardless of scaletype, it’s common practice to verify scale zero visually or to simply rezero the scale prior to each measurement. With the advent of digital scales it is easy to program this feature into the scale. I’m willing to bet your grandmother or great grandmother made sure the butcher’s scale read zero before anything went on the scale, every time!

As for your drift issue I can only speculate as to the cause. The 419 pan weighs ~630grains/41 grams. This is very close to the midpoint calibration weight of 50 grams. If the pan is left on the scale for long periods of time it may result in a creep issue when calibrating the scale. As you load and unload the scale the effects of hysteresis and creep change the response of the load cell. As you noted the handle to me is a concern since that load is not centered on the load cell. That violates common practice when using a scale of any type. Personally I would ditch that pan. If you continue to use it, do not leave it on the scale’s weigh pan during storage.