Viability and General Approach For Automated Dry Ingredient Dispenser

I was recently introduced to Soylent, an alternative method of consuming one’s nutritional needs. It involves mixing a carbohydrate (usually flour), protein powder, and several other dry ingredients, then pouring it in water when it is time to eat. With the right ingredients and the assistance of diy.soylent.me, it is possible to fulfill all of the nutritional needs of a human without going overboard on fats or salts like so many food eaters do every day.

My recipe contains approximately ten dry ingredients, ranging in granularity from table salt to fine cocoa powder. Each ingredient is weighed on a scale before adding to a sandwich bag for storage. The process of creating one 500-calorie meal takes me about 6 minutes per meal, even when I am making several at a time.

I was hoping to automate all of this. I saw someone’s video on Youtube of a “Cookie Perfection Machine”, and that is similar to what I want to do. The only problem with attempting to replicate a design like that is my lack of access to machining equipment required to produce metal parts. I can use hand tools and off-the-shelf parts from hardware stores and internet sites, but I can’t buy a CNC machine to make my own parts.

My design would not require a large rotating mechanism because it will only dispense dry ingredients. That means I can use a central funnel to send the ingredients to a scale. Everything can be stationary, which makes the design simpler. The only moving parts would have to be the mechanisms used to dispense the ingredients.

My biggest challenge and the reason for posting is that I am seeking advice on how to actually dispense the ingredients, given my lack of access to custom parts. Fitting electric motors to rotating devices will be a challenge without custom-made parts. For dispensing some ingredients, I was thinking an electric pepper grinder might work. That might be good for ingredients which only require less than ten grams per meal, but not for flour which requires 75 grams per meal. Any advice on components I could use to dispense ingredients to be weighed would be appreciated.

My goal is to spend less than $250 on parts, but if I have to spend up to $500, I can.

Would you be satisfied with fixed amount of each ingredient or should it be tweakable? Can you mix all the dry ingredients in one large container beforehand and just take from that, or do you need a separate dispenser for each ingredient?

I'm thinking a hopper full of one (or all) ingredient sitting above a "drawer". When the drawer is closed it fills itself with the ingredient that falls from the hopper above it. The drawer has no bottom, but is sitting on a surface that makes the seal. The drawer also has a protruding surface on the top of it to close the hopper as the drawer is opened. As it is opened the ingredients fall out of the bottom. The amount of ingredient dispensed is regulated by the size of the drawer. Unfortunately this does require some manufacturing.

Alternative would be some sort of a screw that pushes the ingredients (again from the hopper above), but unless you can source them they'll be even harder to manufacture.

Shpaget: I'm thinking a hopper full of one (or all) ingredient sitting above a "drawer". When the drawer is closed it fills itself with the ingredient that falls from the hopper above it. The drawer has no bottom, but is sitting on a surface that makes the seal. The drawer also has a protruding surface on the top of it to close the hopper as the drawer is opened. As it is opened the ingredients fall out of the bottom. The amount of ingredient dispensed is regulated by the size of the drawer.

I've seen some brick/block manufacturing equipment that works on this principle, and it seems to be simple, reliable and consistently accurate.

Shpaget: Would you be satisfied with fixed amount of each ingredient or should it be tweakable? Can you mix all the dry ingredients in one large container beforehand and just take from that, or do you need a separate dispenser for each ingredient?

For proper nutrition, each ingredient needs to be measured to a precise amount. Mixing powders tends to result in uneven distribution of the various ingredients throughout the mix. A volumetric-based dog food or cereal dispenser design won't work.

Each ingredient needs to be weighed on a scale, one ingredient at a time. For example, we need about 4 grams of salt per day, so that ingredient needs to be dispensed onto the scale and measured so my meals provide almost exactly that amount. If my meals are inconsistent and I consume 8 grams per day due to inaccurate methods of dispensing, I won't be achieving my goal of eating proper nutrition.

I don't expect perfect precision from my machine. If I'm able to achieve 10% precision, I would consider that a victory.

4 grams? Yikes! That's nearly double what you should be ingesting. 2000 to 2400 mg daily is recommended by most doctors and health departments.

Anyway, You might want to consider a servo that pushes and pulls a sliding block. Above the block would be your ingredient, kept from falling by the top of the block. The block would be pulled back to allow some amount of ingredient to fall, and then it would be pushed forward to drop it onto the scale. Pulling it back to different positions would allow you to dispense larger or smaller amounts at a time. Multiple pull/push cycles would allow you to very accuraely measure and calibrate each ingredient "on the fly".

Ok, so that's a no on mixing all the ingredients. Understandable. The drawer thing does not appeal to you? Peter, was this the sort of machine you saw? https://www.youtube.com/watch?v=ZYbWykY5IPE

I'm looking at diy.soylent.me and I see that ingredients come in either low amounts or hig, rarely in the middle. That's important because if you want to weight each ingredient, you'll need at least two scales. One for low amounts the other for bulkier ingredients.

You could have multiple dispensers over one container sitting on the scale. You measure one ingredient, zero the scale, add the next ingredient to the same container. Once all the ingredients of similar amount are measured you could just take the two containers and join their ingredients.

Take a look at this gunpowder measuring thing. https://www.youtube.com/watch?v=ZYbWykY5IPE

lar3ry: 4 grams? Yikes! That's nearly double what you should be ingesting. 2000 to 2400 mg daily is recommended by most doctors and health departments.

Salt is made of both sodium and chlorine. Four grams of salt equates to 1.8 grams of sodium, which is right where I should be for daily intake. The site diy.soylent.me does all of the math, so I can be confident I'm not using too much of anything and I'm getting enough of everything.

Anyway, You might want to consider a servo that pushes and pulls a sliding block. Above the block would be your ingredient, kept from falling by the top of the block. The block would be pulled back to allow some amount of ingredient to fall, and then it would be pushed forward to drop it onto the scale. Pulling it back to different positions would allow you to dispense larger or smaller amounts at a time. Multiple pull/push cycles would allow you to very accuraely measure and calibrate each ingredient "on the fly".

That makes sense now. I like the idea now that I understand it better. Your idea will work for ingredients which flow on their own. Some ingredients, like cocoa powder, do not flow very well. I might have to experiment with some different dispensing mechanisms for different ingredients.

My only idea was to attach a drill bit to a motor and spin it inside of a piece of plastic tubing which has a funnel glued to the top of the tube to act as a hopper.

Drill bit. That hasn't crossed my mind, but now that you mention it this type of bit might work. You still need a scale that you can interface with Arduino.

I've never used an Adruino, but I was thinking I could connect the scale's LCD output to the Arduino and convert the LCD digit segments using logic. If the Arduino doesn't have enough inputs for doing that, I can find a way to use circuitry to convert digit segments to bits.

Is the name of this product purposeful or accidental as I'm old enough to remember the film. :~