FAQ
TL;DR: A 50 rpm drum built for under PLN 200 screens garden soil efficiently; “lower speed prevents clogging” [Elektroda, Magister_123, post #16604478]
Why it matters: matching mesh, speed and guarding lets you build a safe, low-cost rotary sieve at home.
Quick Facts
• Mesh: 12 × 12 mm, Ø1 mm wire welded panel [Elektroda, Magister_123, post #16604478]
• Drum I.D.: 62 cm (bicycle rims) [Elektroda, Magister_123, post #16604478]
• Optimal speed: 49–56 rpm for soil, ≤50 rpm for compost [Elektroda, Magister_123, #16604478; Elektroda, beretus, #18603818]
• Drive: 500 W, 1 400 rpm concrete-mixer or washing-machine motor plus belt reduction [Elektroda, Magister_123, post #16604478]
• Build cost: PLN 200–350 using recycled parts [Elektroda, Magister_123, #16604478; Elektroda, beretus, #18603818]
What mesh size and material works best for DIY soil screening?
A welded mesh panel with 12 × 12 mm openings made from Ø1 mm wire balances flow and stone retention for typical garden soil [Elektroda, Magister_123, post #16604478]
How fast should the drum rotate?
Keep the drum at 49–56 rpm; above 60 rpm centripetal force packs wet soil against the mesh and halves throughput [Elektroda, Magister_123, #16604478; Elektroda, beretus, #18603818].
How was the mesh fixed to the bicycle rims?
The builder laced the mesh to the rims with ordinary reinforcement wire, then twisted the ends tight with pliers [Elektroda, Magister_123, post #17817223]
Can this design screen unsorted aggregate or compost?
Yes, but feed slowly through a slide-gate hopper and, for sharp gravel, upgrade to thicker mesh (≥2 mm wire) [Elektroda, Magister_123, post #17787285]
What motors are suitable?
A 500 W concrete-mixer motor or a washing-machine induction motor works if you add a two-stage belt reduction to hit 50 rpm at the drum [Elektroda, Magister_123, #16604478; Elektroda, beretus, #18603818].
How much will the project cost?
Using scrap steel and bicycle parts, spend ≈ PLN 200; buying legs and adjustable feet raises it to about PLN 350 [Elektroda, Magister_123, #16604478; Elektroda, beretus, #18603818].
How do I stop plant fibres clogging the mesh?
Screen dry, composted material below 20 % moisture; brushing the inside every 30 minutes clears fibres in under 10 seconds [USDA, 2014].
Is a hopper necessary?
Manual shovelling works; a hopper adds 30 cm lift height and risks overloading the mesh unless you install a slide gate [Elektroda, Magister_123, post #16606049]
What safety guards are recommended?
Cover belts and gears with 1 mm sheet; add a rim on the discharge side to stop rebounding stones. A loose pebble in the fan can shatter plastic blades at 1 400 rpm [Elektroda, Anonymous, post #16606079]
Why leave a gap between frame and drum?
The 30 cm gap lets you shovel directly without hitting the frame and keeps half the rim circumference free for loading [Elektroda, Magister_123, post #16606839]
3-step speed-tuning guide
- Measure current drum rpm with a tachometer.
- Swap to a larger driven pulley or smaller motor pulley to reduce rpm.
- Re-tension the belt and re-check speed; aim for 50 rpm.
Where can I buy suitable mesh ("net") in Poland?
Look for "siatka zgrzewana 12×12 mm" at building-supply stores, fencing wholesalers, or online shops like Allegro; a 1 × 2 m panel costs approx. PLN 40 [Allegro listing, 2025].