iOptron 3 Pound Counterweight For Various iOptron Mounts

iOptron 3 lb Counterweight for Select iOptron Mounts (21mm Shaft Diameter)

Part Number: 8605

Balance Matters—Even When It’s Just Three Pounds

When it comes to astrophotography or smooth manual slewing, proper balance is critical. The iOptron 3 lb counterweight (#8605) is a small but essential component designed to help you achieve precise balance on a wide range of lightweight and portable iOptron mounts.

Whether you're fine-tuning a compact travel rig or offsetting a DSLR on your star tracker, this 3 lb (1.35 kg) weight ensures your mount tracks smoothly and evenly—reducing motor strain and improving accuracy.

Made for 21mm Counterweight Shafts

This counterweight is designed specifically for 21mm diameter counterweight shafts, which are common across iOptron’s lighter mount platforms. It includes a built-in locking hand knob, allowing you to secure or reposition the weight quickly in the field—no tools required.

The weight itself is roughly 3" in diameter and 1.5" tall, with a matte black finish that blends in with most iOptron mount aesthetics. Its compact size makes it ideal for field use where weight savings and portability are a priority.

Compatible iOptron Mounts

This 3 lb counterweight fits a wide variety of iOptron mounts and tracking systems, including:

• SkyHunter

• SkyGuider Pro

• SkyTracker Pro (with CW package #3324)

• SkyGuider (original)

• AZ Mount Pro

• CEM26

• GEM28

• CEM25 / ZEQ25

• iEQ30 and iEQ30 Pro

• MiniTower / MiniTower II / MiniTower Pro

• Cube / CubePro / Cube-A / Cube-G / Cube-E (with CW shaft #8607)

• HEM / HAE / HAZ series mounts

• CEM40 / CEM40EC – Only for early models with 20mm CW shaft

⚠️ Compatibility Note: Some early-production CEM40 and CEM40EC mounts used a 20mm counterweight shaft. Later models use a 28mm shaft and will not be compatible with this weight. Be sure to measure your shaft diameter before ordering.

Technical Specifications

Observing Tip

If you're using a SkyGuider Pro with a longer lens or a full-frame DSLR, you may find the stock counterweight isn’t quite enough—especially if your camera has a battery grip or filter wheel attached. Adding this 3 lb weight to your counterweight shaft can restore perfect balance, improving tracking and reducing the chances of stalling during long exposures.

It’s also a great solution for outreach setups or light payloads where fine balance is still essential, but space and weight are at a premium.

Final Thoughts

The iOptron 3 lb Counterweight (#8605) is a must-have accessory for users of lightweight mounts and trackers who want more balance flexibility without overdoing it. It’s especially useful for mobile astrophotographers and visual observers who need to fine-tune their rig without hauling around heavier counterweights.

Just check your shaft diameter—and your balance will thank you.