help! urgent

Hi All
I have a challenge to create a model distribution invention that can simultaneously distribute sugar equally to 4 containers. Any ideas??

What do you mean with:

Rebeccccca:
(...)
distribute sugar equally
(...)

What is your concept of equally?

So the model has to distribute 250g of sugar at the same time into 4 different containers

In how many time you need to do the measurement?

The model needs to distribute 250g of sugar once and then set up again for random amounts I.e container a:150g b:200g c:250g d:400g

The first question that I made stills without answer. What is for you "equal"?
You need something like 200g +/-1g, and then 199g is equal to 201g.

Do you mean 250g + / - 5g?

Yes, is a good start.

Now, you need to know if you really need to measure the weight or you can only measure the volume, or you can only measure the time that something must to be open to give you that weight.

Ok yes it needs to be measured using graduation measurements I.e beaker or erlenmeyer

you should have some dispenser mechanism that e.g dispense on average 5g/second.
Then it is just timing (open/close) the valve of the dispenser unit.

Another trick might be using sugar cubes (or is that too much out of the sugar box thinkin
These have a fixed weight, then you only need to count them..

Any idea how to actually make that/ what materials I need?

• some reservoir for the sugar
• tubing
• a valve mechanism
• motor to drive the valve (some transistors and separate power to drive the motor)
• an Arduino
• wires
• power supply for the Arduino
• an LCD screen to interact with the user
• some switches to control

Think you need to visit some hardware stores to get inspiration
Sorry I have no complete plan for you.

Google on "Arduino dog food dispenser images"

Thank you so much for your help!!

Ya just open up a valve with a certain per second rate of material flow(grain) and then calculate your way from there to ascertain your quantity in question.

I like the sugar cube counter the best.

First, 150g +/- 5g is 3%, vs 400g +/-5% = 1.25%.

Second, the density of the sugar is going to vary from the top of the bag, coarse, vs the bottom of the bag, fine. OK so dump it into another container first and stir it to make it more uniform. However humidity will also affect the flow. OK so heat the environment (in a cabinet) to drive out the moisture, or do it in an air conditioned environment. Still, an annoying amount of work.

The sugar cubes always weigh the same. Each cube will weigh a little differently in an absolute sense, but on -average- over time the variations will smooth out the error curve.

The Rocket Science answer, accurate to 0.1g and extremely repeatable, is a scale with a container sitting on it. After the sugar is loaded into the container a robotic grabber picks it up and dumps it out.

That's a mechanical PITA - I still like the sugar cubes best. Not that the sugar cubes are necessarily much easier mechanically, but the repeatable accuracy is drastically higher.

Any choice boils down to the accuracy required.

Sugar cubes is the way to go.

But think out of the box a little and away from robot arms to pick and place and think of a PEZ dispenser.

A stack of cubes spring loaded and pushed out one at a time like the sweet dispenser or even gravity fed in a downward direction to allow for a bigger stack.. A simple broken beam detector will tell you when you have nnn cubes left and need to refill the hopper.

Cheers Pete.

Rebeca,

I'm afraid you need (perhaps to yourself) specify your needs, specially in what concerns the final part, i.e.:

• How are the recipients placed (side by side, stacked, . . . . .)
• How they are (cups, boxes, . . .)
• The accuracy you need ( .1%, 1%, 5%, . . . )
• The time it should take

Just to help; if accuracy is a goal, then you may need something like the photo.

Regards

Hello Rebeca,

Just stepping back into this to see how you got on.

If you got it to work would you like to share it with us.

Cheers Pete.