Greenhouse Ventilation Gearbox - Self-Braking - Manual Crank Winder for Polytunnel Roll-Up Curtains

Greenhouse Roll-Up Side Gearbox - Manual Crank for Polytunnel Ventilation

Our Greenhouse Roll-Up Side Gearbox is the core component for providing effortless manual control over your side wall curtains. This robust mechanical winder allows you to precisely manage airflow, regulate temperature, and maintain the perfect growing environment through the warmer months.

Best For Commercial growers, nursery operators, and greenhouse builders needing a robust and reliable mechanical winder for constructing or repairing manual roll-up side ventilation systems on polytunnels and greenhouses.

Key Features

• ✔ Effortless Operation: The internal gearing provides a significant mechanical advantage, making it easy to raise and lower long and heavy side curtains with minimal effort using a crank handle (sold separately).

• ✔ Precise Temperature & Airflow Control: Allows you to make fine adjustments to your side wall opening, giving you precise control over ventilation to manage heat and humidity, which is critical as we head into summer.

• ✔ Self-Braking for Security: Features an integrated self-braking mechanism that automatically locks the curtain in any position. This prevents the curtain from unravelling in high winds and ensures it stays exactly where you set it.

   

• ✔ Heavy-Duty Construction: Built with a durable, weather-resistant housing and robust internal gears, this gearbox is designed to provide years of reliable, maintenance-free service in a demanding greenhouse environment.

How It Works This gearbox is the engine of your manual roll-up system. It is designed to move along a drive shaft (climbing bar). When operated with a crank handle, its internal gears drive the unit up or down the length of your greenhouse, winding the curtain material around a roller bar. This action smoothly and evenly opens or closes the side wall for ventilation.

Specifications

• Product: Manual Greenhouse Gearbox / Winder

• Application: Roll-Up Side Wall Curtains

• Mechanism: Self-Braking Crank Winch

• Housing: Weather-Resistant Casing

Ideal For (Uses)

• Manually opening and closing long roll-up side walls on single-span and multispan greenhouses.

• Precisely controlling ventilation to reduce heat build-up on hot spring and summer days.

• Retrofitting existing polytunnels with a reliable and easy-to-use manual ventilation system.

• Repairing or upgrading old, broken, or inefficient side wall winding mechanisms.

Oversized Item Delivery Options

Oversized, heavy, and structural goods ship via specialist freight. Freight is calculated at checkout from estimated packaged volumetric or physical weight. Carrier depot audits may adjust the rate — if the increase exceeds 10%, we will contact you before processing.

Available options include:

✔ Delivery to your closest depot for pickup — default method
✔ Direct delivery — requires an operational forklift on site unless Tailgate Delivery has been specifically requested and quoted (contact us — this cannot be selected at checkout)
✔ Tailgate hydraulic lift delivery — must be specifically requested; contact us for a quote (not available as a checkout option; extra fees apply; required if you do not have a forklift)
✔ Forklift loading at our warehouse (no extra charge if you arrange your own freight)
✔ Direct truck delivery (available in Victoria)

Important Notes:

• Shipping costs vary by location and method
• Any carton or consignment over 25–30kg (or over 200cm) must be palletised
• Without a specifically requested and paid Tailgate Delivery quote, palletised freight requires a forklift on site — otherwise the carrier will redirect to the nearest depot
• Bulky and oversized items cannot be delivered to a PO Box — provide a physical street address
• Failed deliveries, locked gates, unattended sites, or incorrect business/forklift declarations may incur carrier redelivery, demurrage, and restocking fees as set out in our Terms & Conditions

Business Delivery:

• Selecting a business/commercial delivery rate warrants that the address has an operational forklift and certified operator during business hours
• If the carrier cannot unload, the consignment may be redirected to a depot and secondary fees may apply
• Additional fees may apply for failed delivery attempts due to lack of appropriate unloading equipment

See our Terms & Conditions (Article 8) for full freight and delivery rules.

Important Note on Availability & Shipping

Our warehouse is a logistics hub, not a retail showroom. Listing a product online does not mean it is stored at our Thomastown warehouse — many lines ship from supplier hubs (split fulfilment may apply).

How lead times work:

• Product page ETA: The Estimated Time of Arrival (ETA) / lead-time badge shown on the product page at checkout is the agreed delivery timeframe for that order under Australian Consumer Law.
• Metro baselines: Advertised ETAs apply to standard metropolitan zones. Regional and remote addresses may take longer and may attract surcharges.
• Peak seasons: Orders in March–May, August–October, EOFY (June), Black Friday/Cyber Monday (November), and Christmas/New Year (December–January) may automatically add a 2–4 week buffer beyond the product page ETA.
• Supplier-dependent / backordered items: If stock is delayed, we will notify you with a revised ETA. You then have 7 days to accept the new timeframe or cancel for a full refund.
• Adloheat: Custom-made products from Adloheat (Pakenham, VIC) may take 4–12 weeks depending on the order.

Full fulfilment, cancellation, and freight rules are in our Terms & Conditions.

Biosecurity & Interstate Shipping Restrictions

Due to strict state biosecurity regulations, we are unable to ship some products to certain states and territories:

• Potting Mixes cannot be shipped to Western Australia (WA), the Northern Territory (NT), or Tasmania (TAS).
• Seeds cannot be shipped to Western Australia (WA).

Orders placed for these items to restricted states will be cancelled and refunded. It is the customer's responsibility to ensure that the items being ordered can lawfully be delivered to their state or territory.