Introduction: Compact Composter

Often people living in apartments that do not have access to outdoor spaces but are interested in reducing their waste or producing compost for their indoor plants. This compact composter has two compartments that can compost while also allowing you to reduce odor with a carbon filter. It is able to rotate to allow for aeration while also adding worms will allow for quicker decomposition. The clear design will also let you see the process taking place inside, which will help you know if it is decomposing and provide an interesting view of the process.


Acrylic Sheet: 24" x 48" x .093"

Metal bar: 6' in length and 1" wide

Screen - 12" x 12" x 15"

Carbon Filter - Oval measuring 3.5" x 5"

4 bolts: 3" length

16 Washers

4 Nuts

100% Silicone Sealant

Step 1: Cut the Acrylic Sheet to Create the Box.

Using a Laser Cutter, cut a acrylic sheet into a box that will hold your compost. The box layout is attached. My measurements for the box were 15" x 11" x 11". If you were to create your own box, make sure to add an oval shape able to fit your hand on opposite faces of the box so that you are able to add compost. Add two small holes near these in order to attach the lid. Also, add two small holes on the smaller sides of the box for the legs.

It is important to seal all the edges very well in order to not allow the compost to escape. I recommend sealing with glue meant for acrylic. It is helpful to tape the sides together first and then glue to create the proper shape.

Seal all of the edges except for the top so that you are able to attach the legs and screen later.

Step 2: Create the Lids.

Using a laser cutter, cut 4 the circles, similar in design to a salt shaker lid. The design file is attached. The design offers two holes, one for adding compost, and one that will hold the carbon filter. The section without a hole will allow you to seal the box when spinning it.

The lids in my design are 10" in diameter with spherical holes that are 3.5" tall and 5" wide.

Next, place the carbon filter on top of one of the holes and align another lid above this with the holes lining up. Glue the two pieces of plastic together but without gluing around the carbon filter. This will allow you to remove the filter and replace it with another one when necessary.

Step 3: Attach the Lids.

Using a 4" bolt, attach the lid to the top and bottom faces of the box. Add washers between the layers and firmly tighten the nut to ensure there is no room for it to move freely or allow compost through.

Step 4: Attach the Screen.

Laser cut 8 long rectangles out of acrylic. Create 4 that are 15" tall and .5" wide. Create 4 that are 11" tall and .5" wide. Lay these out on top of a screen and glue the acrylic together. The design file is attached.

Using the acrylic glue, glue the acrylic frame and screen to the middle of the box.

This will allow you to have two sections of your composter.

Step 5: Create the Legs.

Using a 6' length steel pole that is 1" wide, cut it into 4 pieces that are 12" long. Cut a 90 degree angle into the top of two of the poles. Weld these together. Then, drill a .5" diameter whole in the juncture you created between these poles. Weld a 17" length bar to the bottom of these poles to create a triangular shape. Place a 4" bolt in the drill hole with 5 washers on the outside of the box and place the bolt through the hole on the box with a nut. Ensure this is tight in order to reduce wobbling while also allowing the box to turn.

Repeat this step to create the other legs.

Step 6: Glue the Top Onto the Box.

Now that the legs and screen are in place, glue the top onto the box.

Your composter is now finished and it is time to fill it!

Step 7: Begin Using Your Composter!

It is good to add compost to one side of the composter until it is full. Then, you may move on to the second section of the composter. This will allow it to fully decompose without adding new food materials. When completed, remove the compost to be used and begin the process again.

Here is a list of good things to add to your compost and keep a healthy balance for decomposition:

-Food waste (other than meat or dairy products)

-Dry leaves or grass clippings

-Egg shells

-Cardboard or paper

-Tea bags

Add the worms after you have some food waste in there for them to eat! You may turn the composter while worms are inside it. It is good to turn slowly a few times a day to allow for aeration but not create pressure on the worms.

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