Help: Grain dispenser project

Hi! I am doing some research project, and I need to integrate automation for grain dispensing. My aim is to have the dispenser release a specific amount (weight) of grains with high precision. What can you suggest that I use for the dispenser? I have worked before with Instrumentation amps and load cell. I also had tried using load cell with HX711 module, I think I can use that for determining the weight of grains dispensed. Or can you suggest something better (and faster perhaps)? And What can I use for the dispensing of grains?

If u can use a volume... Maybe an idea can be 'stolen' from this one.. https://www.youtube.com/watch?v=ILbAYpr1Us0

Scales and some sort of auger dispensing system seems like the most straightforward solution.

You can use the opamps to compare the signal with a setpoint (that way you dont need a ADC. to get a speed, i would prefill, the sack with about 90% or even closer when possible and the last slow until the weight is in.

gunpower dispenser 'throw' a filled cup of a relatively uniform mass. you can calibrate the volume of the cup and dispense within 1% consistency.

a rotating disk that has a cavity. the cavity goes under the supply and fills the cavity, then it rotates like a ball valve, and when it faces down, the powder falls out. can go very fast, but it is not individually measured to exacting tolerance.

you could start with such a device to throw the 95% volume, then use a smaller sprinkler to top off the scale before going on to the next stage.

the 'sprinkler' used in that process is a spinning tube that is on a slight tilt. the tube spins. the resovour sits over the tube and has a hole, so that each revolution some will fall into the tube. the spinning keeps the grains in motion and they slide down hill. the faster the rotation, or the steeper the tilt, the faster they move downhill.

..last post! Thats the way to go. Using a scale .. depends on humudity and will not be more exaxt

Thanks for eveyone who replied :) I really appreciate it, I'll look on the design, to make something like a gunpowder dispenser. Actually, I only need to dispense 1 specific volume. And it would be fixed. So it's like I have a container or hopper field with small grains/seeds, and then release that specific volume/weight into the point where I want to drop them. The auger solution can be a good to go too. :) Or the disk with cavity. My concern now is how to measure the volume accurately and fast enough not to delay the entire operation. :) thanks again pals! :)

iamwin: Actually, I only need to dispense 1 specific volume.

Initially you said you wanted to dispense a specific weight. What are you actually trying to control - weight, or volume?

iamwin: My concern now is how to measure the volume accurately and fast enough not to delay the entire operation. :) thanks again pals! :)

how fast is fast ?

since most scales have a settling time, you could take random samples.

another idea is to send the volume into a device like a tipping cup rain gauge. fill, weigh, empty

if this is on a high speed production line, then weighing each sample will need to be extremely fast and costs would be expected to be much higher.

first thing that comes to mind is a carousel. have a 1 meter (depending on your volume) that is sliced into 20 individual sections with 20 individual load cells. as it rotates, each indicates when it is weighted properly. angled with a trap door, the unit could pass under multiple dispensers to add more.

at the end, proper weight gets the trap door opened and the product falls into packaging. improper weights get recycled

it seems the old saying comes into play. accuracy costs money, how accurate can you afford to be ?

PeterH:

iamwin: Actually, I only need to dispense 1 specific volume.

Initially you said you wanted to dispense a specific weight. What are you actually trying to control - weight, or volume?

the rotating dispenser could work.

if you needed higher speed, a disk, thick enough so that each hole was about as wide as it was tall, multiple holes on the disk, the dis rotates and the holes fill, get moved on and then dump. this could be very fast.

PeterH:

iamwin: Actually, I only need to dispense 1 specific volume.

Initially you said you wanted to dispense a specific weight. What are you actually trying to control - weight, or volume?

I just mentioned volume since grains can also be measured by volume (given it is placed in a container with known volume), or weight if using load cells instead. either way, I just need to dispense that specific quantity (either by volume or by weight). :)

dave-in-nj:

iamwin: My concern now is how to measure the volume accurately and fast enough not to delay the entire operation. :) thanks again pals! :)

how fast is fast ?

since most scales have a settling time, you could take random samples.

another idea is to send the volume into a device like a tipping cup rain gauge. fill, weigh, empty

if this is on a high speed production line, then weighing each sample will need to be extremely fast and costs would be expected to be much higher.

first thing that comes to mind is a carousel. have a 1 meter (depending on your volume) that is sliced into 20 individual sections with 20 individual load cells. as it rotates, each indicates when it is weighted properly. angled with a trap door, the unit could pass under multiple dispensers to add more.

at the end, proper weight gets the trap door opened and the product falls into packaging. improper weights get recycled

it seems the old saying comes into play. accuracy costs money, how accurate can you afford to be ?

I think what I mean by "fast" is that weighing or determining the volume would take a most 1 second, then actuate the dispensing mechanism :) In terms of accuracy, I agree with you, that to be more accurate, I need more expensive sensors or devices.

The rotating dispenser with fixed volume on container can be a good thing, as it would just need to fill each tank or container, then dispense if the container is filled. :)

thanks again guys!