Intro: Compost Tumbler Sifter
This is my variation on a compost sifter. Since I end up bagging most of my compost to use for later, I decided to create a funnel that would send all the sifted compost into a bag attached to the funnel.
Step 1: The Base With Funnel
In these pictures you can see the base without the sides. The small opening at the end is the funnel to which a bag is bungeed onto.
Step 2: Sides Slide Into Base
In these pictures you can see the sides and how they slot into the base. I did this so I could remove them so the base is easier to store and it allows the base to be used as a table (I cut a separate piece of wood to fit on the base for when I use it as a table). These sloping sides catch any bits of compost as the drum is turning and guide them into the funnel to the bag. The middle section in is screwed down but has a slight gap high enough for the sides to slide under. Everything was sanded smooth and varnished so the compost didn't stick to the wood.
Step 3: Drum Made of Bike Wheel Rims
In these pictures you can see the drum into which the compost is shovelled in. I made it from four bike rims for stability and to support the mesh (make sure before you attach the mesh that the bike rims are not bent so they spin smoothly on the casters). The mesh I used is called Aviary Mesh in the UK. This gave me a strong sieve and a finely sifted compost. I added the quarter moon shape on one end to keep the compost from falling out as I turned it. Some sifter designs I looked at angled the drum so the bigger bits would tumble out of the end. I preferred a semi-closed drum that kept everything inside until I was ready to brush out the bigger bits after sifting. I attached the mesh with zip ties at first but hated using the plastic so resorted to wire which worked just as well though took a little longer to fasten. Better for the environment than the plastic ...
Step 4: Handles for Turning
I added these battens on the outside to use as handles for turning the drum and also help stabilise the mesh (they were screwed to pieces of wood on the inside). I only put in three so there would be an area at the bottom without the wood for a smoother surface when pulling out the bigger bits not sifted (last photo). The battens are cut short to keep them from hitting the boards forming the funnel. The wood on the inside allowed me to screw the circle/lid and quarter moon to the ends.
Step 5: Bag Attached
In these pictures you see the wooden extension that forms the funnel over which I bungee a saved manure bag. I have a lot of these so I built the base and the funnel to this height. If I had a smaller bag I could prop it up with something underneath it so it rested on the ground.
Step 6: Lid for the Big Bits
In these pictures you can see the closed end that keeps things inside the drum till the compost is sifted and the lid that lifts up to pull out the bigger bits. I cut a groove in the wood block, slid in a square bit of aluminum I had laying around and a eye bolt that tightens to hold it in place (see end of video). This keeps one half of the lid closed. The other side is screwed down to the wood battens screwed inside the drum (see earlier pics). A dog clip on a bit of cord holds it open while I pull the bits out. The bits can be pulled out from the other end as well.
Step 7: Video of Sifter in Action
In this video you can see the tumbler in action and how the lid locking mechanism works (done with one hand while the camera is held in the other). Sorry I didn't include any plans or drawings - I built this looking at other designs online and one that a friend had built and modified it in order to make the funnel and the closed ends. It is also wide enough to park a 4-wheeled cart under if I want to haul the compost to dump it right away. I did add a pair of wheels to one end (not shown) so I could roll it near the compost bins. I made the 2x4s at the top of the other end a bit longer to act as handles when rolling it. Thanks to the other tumbler designs for the inspiration! It saves me a whole lotta work and my back is much happier.