Meet the SJ-CMPS1
Key Components
Drum panels — 7 polypropylene panels that form the tumbling barrel
Door panel + 2 doors — sliding doors for loading compost materials and emptying finished compost
Divider — separates the drum into two composting chambers
360° rotating drum — tumbles materials for mixing and aeration
16 vents — promote airflow to support faster decomposition
Powder-coated steel frame — supports the drum for outdoor use
Axle + PVC caps — allow the drum to rotate on the frame
Assembly hardware — includes M5x10 and M6x55 screws and nuts
Technical Specifications
| Specification | SJ-CMPS1 |
|---|---|
| Product Type | Dual-chamber outdoor tumbling composter |
| Best Use | All-purpose composting of biodegradable garden and kitchen waste |
| Capacity | 42 gal / 160 L |
| Weight Capacity | 330 lbs / 150 kg |
| Chambers | 2 |
| Drum Rotation | 360° |
| Vents | 16 |
| Weatherproof | Yes |
| Drum Material | Polypropylene |
| Frame Material | Powder-coated steel |
| Drum Height | 23.5 in. / 60 cm |
| Total Height | 37 in. / 94 cm |
| Total Width | 26 in. / 66 cm |
| Product Length | 22.5 in. |
| Net Weight | 14.3 lbs / 6.5 kg |
| Compost Time | Approximately 2–10 weeks depending on material and temperature |
| Warranty | 2-year limited warranty |
What's in the Box
| Included Item | SJ-CMPS1 |
|---|---|
| Side panels | ✔ 2 included |
| Drum panels | ✔ 7 included |
| Door panel and sliding doors | ✔ door panel + 2 doors |
| Divider | ✔ |
| Axle | ✔ |
| PVC axle caps | ✔ 2 included |
| A-frame tube sections | ✔ 2 included |
| Right angled tube section A | ✔ 2 included |
| Right angled tube section B | ✔ 2 included |
| M5x10 machine screws and nuts | ✔ 56 sets included |
| M6x55 machine screws and nuts | ✔ 2 sets included |
| Manual | ✔ |
Before You Assemble or Compost
Assembly Overview
Attach the door panel
Attach the door panel to the two drum side panels using 4 M5x10 machine screws and nuts.
Install the first drum panels
Install one drum panel under the door panel using 7 M5x10 machine screws and nuts. Repeat for two additional drum panels.
Insert the divider
After installing the six panels, insert the divider between the grooves on the inside face of the drum panels.
Complete the drum
Install the remaining drum panels to complete the composter drum, then insert the two doors onto the door panel.
Install the axle
Press-fit both PVC axle caps on either side of the axle, then slide the axle through the composter drum so it protrudes from both side panels.
Assemble the frame
Snap the frame tube sections together using the spring-loaded push buttons. The frame tube sections require no screws for this step.
Mount the drum to the frame
Secure both sides of the axle and frame together using the two M6x55 machine screws and nuts.
What to Compost
| Material Type | Examples |
|---|---|
| Greens — 2 parts | Raw vegetables, plants, fruit scraps, grass clippings |
| Browns — 1 part | Leaves, twigs, hay, straw, egg shells, coffee grounds |
| Do Not Compost | Meat, bones, cheese, plastic, trash, poisonous plants |
How to Compost
Choose the right location
Place the composter on a flat surface with direct sunlight and enough room for the drum to rotate fully.
Add compost materials
Slide open one door and add biodegradable materials into one chamber. Keep the 2:1 greens-to-browns ratio in mind.
Tumble regularly
Close the door and tumble the drum 5–10 times. Repeat every 2–3 days and every time new material is added.
Use the second chamber
Once one side is full, allow it to decompose and start adding new material to the other side. Each chamber works independently.
Check if compost is ready
Finished compost should look dark brown, feel crumbly, and smell like rich earth instead of rotting vegetables.
Empty the composter
Place a tarp or plastic sheet under the composter, rotate the doors downward, slide the door open, and let finished compost fall onto the tarp.
Compost Timing Guide
| Ambient Temperature | Approximate Time |
|---|---|
| 75°F / 25°C | Approximately 55 days |
| 85°F / 30°C | Approximately 40 days |
| 95°F / 35°C | Approximately 35 days |
Composting Tips
Keep the 2:1 ratio
Use 2 parts greens to 1 part browns. Too many greens may cause odor; too many browns may slow decomposition.
Cut materials smaller
Smaller shredded materials decompose faster. Cut kitchen scraps into small pieces and run a mower over leaves if needed.
Check warmth after 2–3 days
If the compost feels warm to the touch, beneficial organisms are active and breaking down the material.
Moisture should feel like a damp sponge
If the compost feels dry, add a small amount of water and tumble. Avoid adding too much water at once.
Using Finished Compost
Sift for fine compost
Finished compost may contain both fine and coarse material. Sift for a finer blend for flower pots.
Use coarse material outdoors
Use coarser finished compost as top-dressing for outdoor garden beds or till it directly into the garden.
Save some as starter
Reserve a small amount of finished compost as a starter for the next batch or to reactivate a batch that slowed too quickly.
Care + Relocation
Troubleshooting Guide
Use these quick checks for common SJ-CMPS1 composting, odor, pest, and drum rotation concerns.
Possible Causes
- Mix is too wet or too dry
- Not enough nitrogen-rich green material
- Not tumbled frequently enough
- Cold temperature or chamber is nearly empty
Solutions
- Add dry brown materials if the mix is too wet
- Sprinkle a small amount of water if the mix is too dry
- Add greens such as grass clippings or fruit and vegetable scraps
- Tumble 5–10 times every 2–3 days
- Continue adding material until the chamber is at least half full
Possible Causes
- Materials are not shredded small enough
- Incorrect green-to-brown ratio
- Ambient temperature is too low
Solutions
- Chop or shred materials before adding
- Maintain the 2:1 greens-to-browns ratio
- Place the composter in direct sunlight
Possible Causes
- Excess wet green material
- Rain entering through vents
- Insufficient moisture
Solutions
- Add dry brown materials and tumble if waterlogged
- Check all 16 vent covers are properly seated
- Add water lightly and tumble if too dry
- Compost should feel like a damp sponge
Possible Causes
- Mix is too wet
- Not enough oxygen
- Fresh kitchen scraps exposed on top
Solutions
- Add dry brown materials to absorb excess moisture
- Tumble 5–10 times and briefly open the door for air circulation
- Bury fresh scraps under a layer of dry brown material
- Tumble after every addition
Possible Causes
- Meat, bones, dairy, or fatty foods are inside
- Kitchen scraps are exposed
- Mix is too dry or not tumbled regularly
Solutions
- Remove meat, bones, dairy, and oily foods immediately
- Make sure sliding doors are fully closed after each use
- Cover scraps with dry brown material
- Add water and tumble to disrupt ants if the mix is too dry
Possible Causes
- Composter is overloaded
- Frozen material inside the drum
- Axle caps shifted or unseated
Solutions
- Do not exceed 330 lbs / 150 kg
- Remove material if the drum will not turn freely
- Do not rotate when material is frozen; wait until thawed
- Inspect and reseat PVC axle caps
Possible Causes
- Composter is not on level ground
- Frame push-button connections are not fully engaged
- M6x55 axle bolts are loose
Solutions
- Relocate the composter to a flat, level surface
- Remove the drum from the frame before moving
- Press tube sections together until each push button clicks
- Check that both M6x55 axle bolts are secure