Best Way to Stop Grain Flow for Filling Machine

So,
I'm creating a filling machine and decided to go with this design

The logic behind this system is to weight the rice grain, if it hit certain weight (let's say 1000 gr), the free flow will be stopped by something

Any one can suggest how to stop the flow efficiently ?
Maybe using some motor or anything else?

I tried using solenoid valve, but since it's using gravity to fill the bag, the solenoid valve output too little grain

Thanks

Maybe a gear motor with a cam and limit switches.

You might study the shutoff valves used on gravity-driven commercial food and grain dispensers.

https://ecobox.en.alibaba.com/product/60681489538-803468149/2018_Commercial_Dry_Food_Dispenser_Gravity_dispenser_grain_dispensers.html

https://www.displays2go.com/FLP/grain-dispenser

How do the thousands of other mills shut off the bag fill spout?

Paul

jremington:
You might study the shutoff valves used on gravity-driven commercial food and grain dispensers.

https://ecobox.en.alibaba.com/product/60681489538-803468149/2018_Commercial_Dry_Food_Dispenser_Gravity_dispenser_grain_dispensers.html

Bins, Trays & Dispensers

Is it manual? I need something automated by the arduino

Paul_KD7HB:
How do the thousands of other mills shut off the bag fill spout?

Paul

I dunno, that's why I ask it here

A gear has space between the teeth. If it turns inside of a circular container the spaces turn. An opening at the top allows material to fill the space and the gear turns. An opening at the bottom allows material to fall out of the space. Each space must be large enough to qualify as a volume measure for the material. So maybe a hub with dividers that holds 100ml each turn and a stepper motor turning the wheel stop and go. Or maybe 1 deep cup in a small wheel that turns 360 deg to load and dispense 1 measure?

Is it manual?

You should be able to determine that by clicking on the links and studying the contents of the web pages.

Hint: a clever person can convert most "manual" valves into automated valves.

ijoin:
Any one can suggest how to stop the flow efficiently ?

you could possibly use a servo motor to trigger when a certain weight sensor detects the weight of the bag at 950 grams (so it has time to shut of). If you modified the blade of the servo you might be able to stop the flow at the exact time.

i found a weight sensor you could use:

An auger might work - but the design and clearances would need to be such that it would not jam or break the individual grains.

A slide gate might also work - use air for quick actuation

But issues balancing speed of fill and accuracy no matter what method is used. Suggest a bit of searching to see how commercial fillers work -

Leave some clearance in tubes/transports and put a shaker on it helps move things along. Shaker is DC motor with off-center "flywheel".

Compressed air could stop rice falling down a tube.

An auger is the usual with grain.

bluejets:
An auger is the usual with grain.

Auger will be my last option since it's harder to build and maintain

GoForSmoke:
Leave some clearance in tubes/transports and put a shaker on it helps move things along. Shaker is DC motor with off-center "flywheel".

Compressed air could stop rice falling down a tube.

Good idea, will try to look more into it

saildude:
An auger might work - but the design and clearances would need to be such that it would not jam or break the individual grains.

A slide gate might also work - use air for quick actuation

But issues balancing speed of fill and accuracy no matter what method is used. Suggest a bit of searching to see how commercial fillers work -

Yeah, the only problem is auger tends to break the grain
I will use butterfly valve to close the flow

Death_Pacito6:
you could possibly use a servo motor to trigger when a certain weight sensor detects the weight of the bag at 950 grams (so it has time to shut of). If you modified the blade of the servo you might be able to stop the flow at the exact time.

i found a weight sensor you could use:

https://www.sparkfun.com/products/10245

Thanks

GoForSmoke:
A gear has space between the teeth. If it turns inside of a circular container the spaces turn. An opening at the top allows material to fill the space and the gear turns. An opening at the bottom allows material to fall out of the space. Each space must be large enough to qualify as a volume measure for the material. So maybe a hub with dividers that holds 100ml each turn and a stepper motor turning the wheel stop and go. Or maybe 1 deep cup in a small wheel that turns 360 deg to load and dispense 1 measure?

Thanks, good idea and insight

In the end, I think i will use butterfly valve

use pressurized air to blow across the opening of the gravity feed grain source pipe. This will create a vacuum in the pipe to help with gravity to move the grain down the pipe, as well as clear the "nozzle" of any irregular grain.the pressurized air can move the grain horizontally to a larger exit pipe and the air can be exhausted at one end of the horizontal pipe, which can have a air filter that can be removed to access for clearing jams and maintenance. A solenoid can control the air flow and when there is no air, the grain will build up in the horizontal pipe and stop the flow.

You could also squeeze the outside of the feed tube if the wall of the tube is soft, we did something like that with a valve that was shaped like a spool and we put air on the outside of the valve. Maybe a second tube at 90 degrees to the feed tube and inflate the second tube to shut off the flow.

ijoin:
Auger will be my last option since it's harder to build and maintain
Good idea, will try to look more into it

Yeah, the only problem is auger tends to break the grain
I will use butterfly valve to close the flow

ThanksThanks, good idea and insight

In the end, I think i will use butterfly valve

Your heading was " Best Way to Stop Grain Flow for Filling Machine" and further in your original query was " Any one can suggest how to stop the flow efficiently ?" ...hence the auger solution as that is the normal approach.

If that does not suit, that's fine but it does answer your query nevertheless.

Butterfly valve will jam.

With a butterfly valve, consider that the valve vane has to push falling grain ‘out of the way’.
This creates an extra variable load on the shutter mechanism.