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[NineInchNails]

I could not find an appropriate place to ask this question so I figured I'd ask here. Feel free to delete or move this post if it is inappropriate.

I am searching high and low for a digital scale with a controller that will turn a dispensing pump fir instance off once the weight has reached the set value. I didn't see any on our website. Have you guys considered a controller for digital scales? If you guys made a controller, supplied or recommended a compatible scale ... it could be a big seller! Many people use dispensing pumps, auger dispensers for dry materials, gravity fed solenoids (for on/off) and that's just the tip of the iceberg. Maybe like a PID learning function because some liquid nozzles for instance, when shut off, can drip or dribble a little. Some may use drip-proof nozzles.

Anyway, I've been a customer of yours for years. I've been searching for a digital scale with a controller, but haven't found one yet. I bet this is a part of industry where you guys could do very well. There are a LOT of small businesses that package a lot of different materials/products, but do not want to spend thousands and thousands of dollars on a piece of packaging equipment.

[Kkane]

I will get back to you early next week.  Thanks.

[NineInchNails]

I very much look forward to hearing from you.

[Kkane]

I sent you an email but no reply yet. Here are my questions:

1. May I know what is the maximum capacity you need for this scale?

2. How accuracy (reading resolution) you prefer for this scale? Is 1oz or 1g enough?

3. May I know more details for your application/setup?

[NineInchNails]

Sorry, I got your response, but I haven't had time to answer yet. I Should be able to tomorrow.

[NineInchNails]

1. May I know what is the maximum capacity you need for this scale?
For most uses, we will be filling 32oz and 16oz bottles. The weight is typically similar to water. The most should be around 955 grams of material or just over 2 lbs (not including the weight of the bottle). The weight of the bottle is about 50g.

2. How accuracy (reading resolution) you prefer for this scale? Is 1oz or 1g enough?
We like to be within 3 grams above or below 955g.

3. May I know more details for your application/setup?
We are currently using this bottle filling machine . Basically is uses this electric diaphragm pump and a precise timer. In theory this should work, but there are too many variables that make this and similar machines unreliable accuracy & repeatability wise if precision matters.
1. One nozzle can tend to put out more than the other. It shouldn't, but it happens.
2. Varying difficulty of the pump sucking material. Full reservoir = easier to suck. Low reservoir = harder to suck. We tried elevating the reservoir for more consistent feed pressure and that caused issues.
3. Inline filter becoming increasingly more clogged can influence flow rate.

The above variables have forced me to replace one of the nozzles with one that joins the other one side by side. Now instead of filling 2 bottles, we are filling 1 with both nozzles. That helps, but still the flow rate is not reliable with a timer. We still end up having to weigh every single bottle, add or take some material out each time. We are forced to under-shoot the weight and add more just to have some kind of repeatability. A true volumetric filling machine (using a stroking cylinder) would be fine, but I'm convinced that electric automation between a controller and a scale should be a viable solution as well as more versatile.


For controllers, we have some PID controller or thermometers which can read 0-5V or 4-20mA signal, or 0-400 Ohms resistance.
I have assembled several PID controllers before so I am familiar with basic, straight forward stuff, but I am not that familiar with scales. I do not know of a scale that you can connect a PID controller to. I would be appreciative of any guidance you can offer. If you would prefer to discuss any details over the phone then let me know. I know it's sometimes easier to discuss in more detail over the phone in comparison to typing.

[NineInchNails]

This is basically what I'm thinking about doing as long as I can find a controller that will work with a scale.

[Kkane]

I just sent you an email for this case. If you haven't received that email, please contact us here:
https://www.auberins.com/index.php?main_page=contact_us

[Kkane]

I sent you an updated email this Monday, but still no reply. Could you please check your email please?