Instructables
   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!! : )
 
Remove these adsRemove these ads by Signing Up

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

Picture of ToO - Theory of Operation
diagram1.jpg
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

DSCN0163.JPG
DSCN0165.JPG
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!!

1-40 of 43Next »
hellspawned9 months ago

Nice job!

gluvit11 months ago
Like it
(removed by author or community request)
Maybe you could scrap the heating element out of a cheap toaster...
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/
fozzy13 (author)  augur453 years ago
Thanks for the comment and information!!

I have already been thinking about a nichrome heating element desgin. : )
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.
fozzy13 (author)  whiteoakart3 years ago
Haha, the things we will do to get around the rules.

Thanks for the comment!!
(removed by author or community request)
fozzy13 (author)  DELETED_deyb13 years ago
I'm happy to help. Good luck with your project. Thanks for the comment!!
fozzy13 (author)  DELETED_deyb13 years ago
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!!
sjoobbani3 years ago
If you don't have a riveter, use pipeclamps!
fozzy13 (author)  sjoobbani3 years ago
Good idea!!

Thanks for the comment!!
(removed by author or community request)
fozzy13 (author)  DELETED_kage_no_akiri3 years ago
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!!
(removed by author or community request)
fozzy13 (author)  DELETED_kage_no_akiri3 years ago
Thanks!! I can't wait to see the Instructable. A rheostat with a heating element would definately be a great upgrade.

Thanks!
ralls19353 years ago
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.
Very very cool.
fozzy13 (author)  HeresyOfTruth3 years ago
Thank you and thanks for the comment!!
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.
fozzy13 (author)  GrumpyOldGoat3 years ago
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!!
jolshefsky3 years ago
Finally: a real use for those popcorn tins I keep picking up! Too lightweight for any practical storage (aside from popcorn, everything is too heavy), and crumbs get into the cracks. But they are fairly large!
fozzy13 (author)  jolshefsky3 years ago
Yes!! Those would work well.

Thanks for the comment!!
Nice! It doesn't matter what it looks like, you made it and it works. Some folks just talk and don't make.

I like it, though it is a bit small if you pick mushrooms like we do here. They grow by the sackloads :) I guess one could scale this up using larger cans like restaurants use. They just throw them away. Good materials free for the asking.

Mine is featured on the right side of the page, I use it every season and have gotten great pleasure from it. You will, too!
fozzy13 (author)  stringstretcher3 years ago
Thanks!!

It is a bit small, but I only assumed I would need a small one since I'm just doing this for fun and not storing anything I grew. Restaurants do use larger cans that would be great for this project.

Thanks for the comment!!
shilohjim3 years ago
This is a cool mini dehydrator.

May I suggest the book 'Dry it You'll Like it'. It explains the proper temps for dehydrating and says that a fan isn't needed. You get the thermal convection from the rising heated air. You're not trying to cook the food just dry it so very little heat is needed.
fozzy13 (author)  shilohjim3 years ago
Thanks!

That book sounds really cool, and I have actually seen some designs for convection-based dehydrators, even some that use the sun to generate the heat. I like the process but thought that using a fan would be a simpler way to make a functioning unit my first time around.

Thanks for the comment!!
Just saying, this sounded really gross to me at first.

You may want to reword the title to something like Food Dehydrator from Recycled Parts. I don't think anyone wants to dehydrate their recycled food. haha

But then again, I could be wrong...
fozzy13 (author)  skittlespider3 years ago
Haha, I will have to think about changing the title. I had not considered reading it that way. Even still, I asume people don't recycle their food, but hey, I won't judge.

Thanks for the comment!!
Your welcome. I'm always glad to provide a different viewpoint.
Exscaly3 years ago
Whoa! This looks so cool! Good job.
fozzy13 (author)  Exscaly3 years ago
Thank you and thanks for the comment!!
Udon3 years ago
It really looks crazy - I like it. :P.
fozzy13 (author)  Udon3 years ago
Thank you and thanks for the comment!!

I like the look of it too, even if it is unconventional.
Andsetinn3 years ago
As far as I can tell, from the drawing, the light bulbs and fan are connected in parallel although the text says series. Nice work though. :)
fozzy13 (author)  Andsetinn3 years ago
Thanks for pointing that out!! Yes, I did mean to type "parallel" instead of series. I fixed it.

Thank you, and thanks for the comment!!
dataphool3 years ago
Your wiring is rather unclear from your written description. A diagram would be helpful. There is only one way to hook it up in series, but you have not explained why you would hook up 3 switches in series, since each switch turns the device on or off. Do you just want to complicate matters?

I suspect you of excess verbiage, and excess parts. Does your device needs the motor controlled by a switch? Or could you control the fan power with a hand on the wall plug?

What is the purpose of the lights? Do they provide light, or heat? Light but no heat could be supplied more efficiently with LEDs. Heat, but no light could be supplied by a resistive heating element. I think I know what you mean, but ...
fozzy13 (author)  dataphool3 years ago
Hey, thanks for the comment : ) I believe I included a type of wiring diagram in Step 4, and tried to explain it the best I could. The three switches were used so that I could decide how much heat I wanted to use, based on how many lightbulbs were on. 

The motor does not need a switch, but I wanted to include one.

So Yes, the lightbulbs were used for heat, not light.  I did not have any resistive heating element available, and many other designs I had seen online used lightbulbs.

It's not a perfect project, but it was free, it works, and I had fun putting it together.

Thanks for the comment!
ChrysN3 years ago
Cool! I love dried apple chips, the apple cinnamon granola you made looks yummy.
1-40 of 43Next »