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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
ZWO Counterweight Bar for AM5 Mount
ZWO Counterweight Bar for AM5 Mount
ZWO Counterweight Bar for AM5 Mount
ZWO Counterweight Bar for AM5 Mount
ZWO Counterweight Bar for AM5 Mount

ZWO Counterweight Bar for AM5 Mount

by ZWO
SKU ZWO-BC230
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Price Match Policy!
  • Extends AM5 mount payload capacity beyond 28 lbs
  • 230 mm (9") total length for flexible balancing
  • Standard 0.787" (20 mm) diameter fits common counterweights
  • M12x1.75 thread for direct connection to the ZWO AM5
  • Solid, oxidation-resistant metal construction
3 in stock
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • ZWO Counterweight Balance Bar for AM5 Mount

    The ZWO Counterweight Balance Bar for AM5 Mount is a 230 mm (9") solid metal shaft required for balancing imaging payloads over 28 lbs. Its standard M12x1.75 thread and 0.787" (20 mm) diameter ensure a secure fit to the mount and compatibility with a wide range of third-party counterweights, allowing you to safely mount heavier optical tubes.

    Unlocking AM5 Payloads Beyond 28 lbs

    The ZWO AM5's strain wave drive is engineered for counterweight-free operation with payloads up to 28 lbs (13 kg). To push beyond this limit, this counterweight bar is the essential component. It threads directly into the base of the AM5 mount head, providing a rigid, stable axis for adding mass to perfectly balance heavier OTAs like large refractors or Schmidt-Cassegrains.

    Standard 0.787" Shaft for Broad Counterweight Compatibility

    This bar's 0.787" (20 mm) diameter is a common standard in the astronomy market, freeing you from proprietary counterweight systems. You can use widely available counterweights that feature a 20 mm bore, such as the iOptron 10 lb counterweight for the CEM25 or the Explore Scientific 9.9 lb counterweight for the EXOS2-GT. This flexibility allows many users to integrate the bar with counterweights they may already own.

    M12x1.75 Thread and Solid Metal Build

    Built from a single piece of oxidation-resistant metal, the ZWO BC230 bar is designed for maximum rigidity and longevity. The precision-cut M12x1.75 thread provides a secure, no-slip connection to the mount that won't loosen during a session. This robust construction prevents flexure that could otherwise degrade the AM5's precise tracking accuracy when carrying heavy loads.

  • At what payload weight do I need the ZWO Counterweight Bar for my AM5?

    ZWO recommends using this counterweight bar and a separate counterweight for any imaging rig that weighs more than 28 lbs (13 kg). This ensures stable tracking, protects the mount's internal drive system from excessive strain, and provides a critical margin of safety.

    What size counterweights fit the ZWO BC230 Counterweight Bar?

    The counterweight bar has a standard 0.787" (20 mm) diameter. Any counterweight with a 20 mm bore will fit securely. This includes many common counterweights from other brands, such as the iOptron 10 lb Counterweight for the CEM25 mount.

    Can I use this ZWO counterweight bar on a mount other than the AM5?

    Yes, potentially. The bar uses a standard M12x1.75 male screw thread to attach to the mount. It is compatible with any mount that features a matching M12x1.75 female thread for its counterweight shaft.

    I'm mounting a 30 lb Celestron C11 OTA on my ZWO AM5. Is this bar enough?

    This bar is the necessary first component for that setup. For a 30 lb payload, you will need this 230 mm bar plus at least one 10 lb or 11 lb counterweight (sold separately) to achieve proper balance. Balancing is critical for maintaining the AM5's tracking accuracy with heavier telescopes.

    Will the ZWO Counterweight Bar help balance a long refractor like a 130mm f/7, even if it's under 28 lbs?

    While not strictly required for payloads under 28 lbs, adding a counterweight can significantly improve stability for physically long instruments. A long OTA creates a large moment arm, and balancing this with a counterweight reduces strain on the mount's gears, leading to smoother, more reliable tracking, especially in windy conditions.

    How do I install the ZWO Counterweight Bar on the AM5 mount?

    Installation is simple:

    • Loosen the small locking screw located at the bottom of the AM5 mount head.
    • Thread the counterweight bar into the mount base until it is hand-tight.
    • Slide your counterweight(s) onto the bar and lock them in place.
  • SKU ZWO-BC230
    MPN ZWO BC230
    Shaft Length 9" (230 mm)
    Shaft Diameter 0.787" (20 mm)
    Mounting Thread M12x1.75
    Warranty 2-Year ZWO Warranty

    • ZWO Counterweight Bar for AM5 Mount

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  • ZWO 2-Year Limited Warranty