Recycled Parts Food Dehydrator

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About: I'm a Mechanical Engineer who has been a part of this community for over 10 years! My interests have evolved over time, and now center around 3D printing.

Intro: Recycled Parts Food Dehydrator

   During one of my many voyages traveling the internet I stumbled across food dehydrators, and thought they were cool.  It also seemed apparent that it was fairly easy to build a functional one and start drying fruits, vegetables, and jerky.  I simply had to make one.

   This Instructable is showing what I did to make a food dehydrator using only recycled materials.  The result of this was a food dehydrator that works, but looks like something out of a nuclear apocalypse (which I kind of like).

   Materials are listed in the next step, followed by the ToO(Theory of Operation), so skip to Step 3 for the start of the build! 

**This project involves using power tools, sharp edges of tins cans, heat, solder, and mains voltage electricity.  Proceed at your own risk and be smart.

Thanks for the feature!! : )

Step 1: Materials/Tools

I used the following materials and tools to make my food dehydrator:
 * Tin cans. 
          These came from diced peaches. (MMmmm peaches..)
 * A fan.
          This was the cooling fan from a broken microwave.
 * Lightbulb.
          I used two small lightbulbs taken from broken vacuum cleaners.
 * Wires, swtiches, and solder.
          The wires and switches were taken from old vaccuum cleaners and the microwave.
 * Rivets, and a riveter.
          Not salvaged, but a rivet tool and rivets can be bought cheaply.
 * A Dremel rotary tool.
          I used this to cut parts of the plastic base to mount my switches.
 * A can opener.
          This was used to remove the tops and bottoms of the tin cans.
 * Sheet Metal sheers.
          I used an "Open-it!" contraption that I found in the kitchen, and it worked.
 * Soldering Iron.
          This was used for connecting the wires and switches.
 * A drill.
          This was used to drill holes in the tin cans so that they could be riveted together.
 * Hot glue gun.
          This was used to attatch light bulbs to the cans and cans to the base, as well as insulate wire connections.

Step 2: ToO - Theory of Operation

This step will tell briefly how a food dehydrator works.  The process is not as complicated as one might expect.

Electricity drives the fan, which moves air through the device.

The air passes over the (red) heating element or lightbulb to increase temperature.

With the air passing over the food, the water molecules within the food change from liquid to vapor, and are driven out of the machine through the top.

This makes the food "dry" by removing the water molecules from the food.  With the absence of moisture in the food, bacteria cannot grow, allowing the food to keep for a very long time without spoiling.

Step 3: The Build - Housing

The first thing that needed to be done was to remove the tops and bottoms of the cans with the can opener, forming short tubes.

Next, the metal sheers were used to cut down the edge of the can, so that it could be stretched out.  This was done to incease the diameter of the can, to better fit the fan.

A piece from another can was cut to fit over the gap in the first can.  Holes were drilled in both cans, and rivets were used to fasten them together.

More cans were cut and riveted together in a similar fashion and riveted to the top of the first can, forming the housing where air will blow through.

Step 4: The Build - Electronics

The electronics I used in this project are simple and crude, just the way I like them.

I cut a mains(wall outlet) plug from a broken vaccuum cleaner to be able to give electricity to the dehydrator.

From there, one of the wires from the mains plug was soldered to a mess of wires connecting it to both light bulbs and the fan.

The other wire of the mains plug was soldered (again through a mess of wires) to three switches, one switch for each light bulb, and one for the fan, and from the switches to the opposite leads of a lightbulb or fan.  I decided to have three separate on/off switches so that I would be able to manually control how much heat from the light bulbs and air flow from the fan was given to whatever I was drying.

Put simply , mains power was connected to two light bulbs and a fan in parallel, through three separate switches.

Check out the pictures and image notes.

Step 5: The Build - the Food Shelf

In this step the shelves are made that the food will rest on top of as it is dried.

I started by cutting aluminum pop cans into squares and drilling many tiny holes into them to allow the air to flow through.

The edges of the square aluminum pieces were folded up to make small trays.

Two parts of a tin can were cut to serve as the top and bottom of the shelf, and they were connected with two metal rods that had female threaded ends, so that the tin pieces could be screwed to them.

Notches were cut into teh metal rods, so that copper wire could be used to twist-tie the aluminum porous trays to the rods.

After doing all this, the shelf was too long, so pieces of a tin can were cut to make the shelf stand off the cans that form the housing, and allow better air flow.

Take a look at the pictures and image notes if this all sounds confusing.

Step 6: Using the Dehydrator/Final Products

Follow these instructions to use your dehydrator.
  1.  Place thinly sliced fruit or other food item onto aluminum trays.
  2.  Insert food shelf into the top of the dehydrator.
  3.  Plug dehydrator into a 120v AC outlet.
  4.  Turn dehydrator on using switches.
  5.  Wait anywhere from 6-12 hours for the food to dehydrate.

I mainly wanted to use this dehydrator for drying apples.  It is important for apples to be brushed with lemon juice before putting them in the dehydrator to keep them from getting brown and nasty. 

There are some pictures of apple pieces that I dried below, along with possibly the most delicious and healthy food I have ever made: Apple Cinnamon Granola!  I wish I had written down the recipe as I was making it, but I just eyeballed ingredients until it looked right.  It tasted just like apple pie, with no guilt.

Thanks for reading!!

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    41 Discussions

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    humxa

    3 years ago on Introduction

    are the bulbs for heat? and does this have to made out of metal can't I make one with recycled plastic?

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    fozzy13humxa

    Reply 3 years ago on Introduction

    The bulbs are in fact for heat. If you are only going to use yours for fruits and vegetables it's probably not necessary however. You can use anything for the housing. I've seen them made with wood and plastic before, but they should be food grade.

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    gluvit

    4 years ago

    Like it

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    jcampbell

    5 years ago on Introduction

    Maybe you could scrap the heating element out of a cheap toaster...

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    augur45

    7 years ago on Introduction

    1) I think incandescent bulbs will be available for several more years. There are many industrial and business devices that use these bulbs where fluorescents or lcds are not practical such as in rough service environments where bulbs are subjected to heat(ovens), cold(refrigerators) and/or vibration.

    Try contacting http://www.buylighting.com/Incandescent-Light-Bulbs-s/165.htm to see what their plans for the future are.


    2) Time for a Maker to come up with a safe nichrome (or other) heating element that can be custom wound to appropriate heat output. I have a boot dryer that uses a pair of ceramic power resistors that disipate 16 watts each.

    http://jacobs-online.biz/nichrome_wire.htm

    http://www.reptilesupply.com/index.php?cPath=30_70

    http://www.ohmite.com/cgi-bin/param_search.cgi

    http://www.resistorsonline.com/

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    fozzy13augur45

    Reply 7 years ago on Introduction

    Thanks for the comment and information!!

    I have already been thinking about a nichrome heating element desgin. : )

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    whiteoakart

    7 years ago on Introduction

    I have heard that over in Europe, to get around this law, they repackage incandescent bulbs as 'heat lamps", which are perfectly legal. Same bulb, new name.

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    fozzy13

    7 years ago on Introduction

    I'm happy to help. Good luck with your project. Thanks for the comment!!

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    fozzy13

    7 years ago on Step 4

    Thanks!! I can't wait to see the Instructable. A rheostat with a heating element would definately be a great upgrade.

    Thanks!

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    fozzy13

    7 years ago on Step 4

    I used three switches so that I could choose to have one light bulb on or two, to regulate heat, and I used another one for the fan because I felt like I should have one. Maybe I overcomplicated it, but I like how it turned out : )..

    If you decide to make one make sure to post some pictures at least!!

    Thanks for the comment!!

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    ralls1935

    7 years ago on Introduction

    if you would like to build a unit that will dry a large amount check out Backwoods mag online and look through their arcvie articles the have a good one.

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    fozzy13

    7 years ago on Introduction

    It is to my knowledge that at some point in the next few years incandescent bulbs will not be sold anymore in an effort to reduce our(The USA's) energy consumption.
    However, the bulbs I used were salvaged from old vaccuum cleaners, so that is an option. Toasters, hair dryers, electric ovens, electric grills, crock pots, and many other common appliances use heating elements that can be salvaged. The heating element often can be omitted from the design as well.

    Thanks for the comment!!

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    Just a thought, but an enclosed base that allowed the use of air filters to remove any airborne particles before it finds, and sticks to, the food.

    All in all another Excellent project that covers the basics to prove the theory so that larger systems can be designed and built with this as the model.

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    fozzy13GrumpyOldGoat

    Reply 7 years ago on Introduction

    I did think about air filters, but it was too much work for this model, but there is room on it where I could at them at a later point.

    Thanks for the comment!!