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Counterweights

Balance is free performance. A correctly balanced mount asks less of its motors, guides more smoothly, and holds tracking better in wind — and getting there costs nothing but the right counterweight in the right place. David Astro carries counterweights in Canada across the common shaft diameters, along with extension bars and shaft accessories, held in our Canadian warehouse.

Shaft diameter is mount-specific and not always documented clearly. Tell us your mount model and payload and we will specify the weight.

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Baader Planetarium Balancing Weight 1kg, with ¼" photo thread (male/female)
CA$83.00 - CA$83.00
CA$83.00
CA$83.00 - CA$83.00
CA$83.00

Baader Planetarium Balancing Weight 1kg, with 1/4" photo thread (male/female)

BAA-2951401

1kg Counterweight Stainless Steel Construction Universal ¼" Photo Thread Male and Female Threads for Stacking Description FAQ Specifications In...

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CA$83.00 - CA$83.00
CA$83.00
CA$83.00 - CA$83.00
CA$83.00
Baader Planetarium Balancing Weight 1kg, Ø75 x 30mm – for Ø16mm Balancing Shaft
CA$148.00 - CA$148.00
CA$148.00
CA$148.00 - CA$148.00
CA$148.00

Baader Planetarium Balancing Weight 1kg, Ø75 x 30mm – for Ø16mm Balancing Shaft

BAA-2951390

Weight: 1kg Shaft Diameter Compatibility: 16mm Outer Diameter: 75mm Thickness: 30mm Description FAQ Specifications In the Box Warranty ...

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CA$148.00 - CA$148.00
CA$148.00
CA$148.00 - CA$148.00
CA$148.00
Baader Planetarium Balancing Weight Set for Planewave OTA
CA$456.00 - CA$456.00
CA$456.00
CA$456.00 - CA$456.00
CA$456.00

Baader Planetarium Balancing Weight Set for Planewave OTA

BAA-2951450

Precision balancing for Direct Drive mounts Rear-mounted design avoids optical path obstruction Protects OTA stability and collimation Mounts dire...

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CA$456.00 - CA$456.00
CA$456.00
CA$456.00 - CA$456.00
CA$456.00
Baader Planetarium Mounting Block for M14 Balancing Shaft, straight – for PlaneWave CDKs
CA$70.00 - CA$70.00
CA$70.00
CA$70.00 - CA$70.00
CA$70.00

Baader Planetarium Mounting Block for M14 Balancing Shaft, straight – for PlaneWave CDKs

BAA-2451549

Mounting block for M14 balancing shafts Straight-through, non-angled design Engineered specifically for PlaneWave CDK telescopes Component part fo...

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CA$70.00 - CA$70.00
CA$70.00
CA$70.00 - CA$70.00
CA$70.00
CA$188.00 - CA$188.00
CA$188.00
CA$188.00 - CA$188.00
CA$188.00

Celestron Counterweight 17 lbs for 19mm Shaft

CEL-94189
1 in stock

Balances payloads up to 17 lbs (7.71 kg) Designed for 19mm (0.74") diameter counterweight shafts Compatible with Celestron Advanced VX, CG-5, CGEM...

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CA$188.00 - CA$188.00
CA$188.00
CA$188.00 - CA$188.00
CA$188.00
CA$125.00 - CA$125.00
CA$125.00
CA$125.00 - CA$125.00
CA$125.00

Celestron Counterweight - 11 lbs for 19mm Shaft

CEL-94203
1 in stock

Adds 11 lbs (5 kg) of balancing force Designed for 19mm (0.74") diameter counterweight shafts Compatible with Advanced VX, CG-5, CGEM, CGEM II, an...

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CA$125.00 - CA$125.00
CA$125.00
CA$125.00 - CA$125.00
CA$125.00
CA$86.00 - CA$86.00
CA$86.00
CA$86.00 - CA$86.00
CA$86.00

Celestron Counterweight - 12 lbs for 19mm Shaft

CEL-94286
3 in stock

Adds 12 lbs (5.44 kg) of balance capacity to your mount Designed for Celestron mounts with a 19mm (0.74") counterweight shaft Compatible with Adva...

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CA$86.00 - CA$86.00
CA$86.00
CA$86.00 - CA$86.00
CA$86.00
CA$257.00 - CA$257.00
CA$257.00
CA$257.00 - CA$257.00
CA$257.00

Celestron Counterweight - 22 lbs for 32mm Shaft

CEL-94187
1 in stock

Adds 22 lbs (9.98 kg) of balancing mass to your equatorial mount Designed specifically for heavy-duty 32mm (1.26") diameter counterweight shafts O...

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CA$257.00 - CA$257.00
CA$257.00
CA$257.00 - CA$257.00
CA$257.00
Explore Scientific Counterweight 5 Pounds
CA$84.00 - CA$84.00
CA$84.00
CA$84.00 - CA$84.00
CA$84.00

Explore Scientific Counterweight 5 Pounds

ES-EXOS2CWB5

Weight: 5 pounds Compatibility: Explore Scientific EXOS-2 and EXOS-2GT Mounts Locking Mechanism: Large, secure hand-tightening knob Finish: Black ...

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CA$84.00 - CA$84.00
CA$84.00
CA$84.00 - CA$84.00
CA$84.00
CA$69.99 - CA$69.99
CA$69.99
CA$69.99 - CA$69.99
CA$69.99

Explore Scientific Counterweight Set for Truss Tube DOB

ES-DOB-CW

Counterweight Set for ES Truss Tube Dobsonians Includes Two Counterweights Balances Heavy Accessory Loads Direct-Fit Installation on Primary Mirro...

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CA$69.99 - CA$69.99
CA$69.99
CA$69.99 - CA$69.99
CA$69.99
Explore Scientific EXOS-2/EXOS-2GT Counterweight 9.9 Pounds - Black
CA$63.00 - CA$63.00
CA$63.00
CA$63.00 - CA$63.00
CA$63.00

Explore Scientific EXOS-2/EXOS-2GT Counterweight 9.9 Pounds - Black

ES-EXOS2CWB

Official component for Explore Scientific EXOS-2 and EXOS-2GT mounts Essential for balancing telescope optical tubes and imaging payloads Reduces ...

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CA$63.00 - CA$63.00
CA$63.00
CA$63.00 - CA$63.00
CA$63.00
CA$85.00 - CA$85.00
CA$85.00
CA$85.00 - CA$85.00
CA$85.00

Farpoint 2 lb Add-On Ring Weight for 12" or 16" Weight Set

FAP-FP315
Only 1 left!

This add-on weight works in conjunction with the basic weight sets (three 1 pound weights) for the 12" & 16" Meade LightBridge telescopes, Zhum...

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CA$85.00 - CA$85.00
CA$85.00
CA$85.00 - CA$85.00
CA$85.00
Sold out
CA$68.00 - CA$74.00
CA$68.00 - CA$74.00
CA$68.00 - CA$74.00
CA$68.00

Farpoint Knob/Spring Kit - Meade LightBridge

FAP-FP320

Upgrade standard telescope primary mirror collimation springs and collimation knobs with Farpoint Knob/Spring Kit. These replacement springs are ma...

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CA$68.00 - CA$74.00
CA$68.00 - CA$74.00
CA$68.00 - CA$74.00
CA$68.00
Sold out
CA$59.00 - CA$59.00
CA$59.00
CA$59.00 - CA$59.00
CA$59.00

iOptron 1.35kg Counterweight

IOP-8605
2 in stock

1.35 kg (3 lb.) Weight For 20mm Diameter Counterweight Shafts 20.5 mm Inner Diameter Bore Compact 79 mm Outer Diameter Description FAQ Specific...

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CA$59.00 - CA$59.00
CA$59.00
CA$59.00 - CA$59.00
CA$59.00
CA$265.00 - CA$265.00
CA$265.00
CA$265.00 - CA$265.00
CA$265.00

iOptron 10kg Counterweight for CEM120

IOP-7326

10 kg (approx. 22 lbs) Weight Designed for iOptron CEM120 Mounts Ensures Proper Telescope Balance Improves Tracking Accuracy and Motor Longevity E...

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CA$265.00 - CA$265.00
CA$265.00
CA$265.00 - CA$265.00
CA$265.00
iOptron 10kg Counterweight for CEM120 (Low Latitude)
CA$319.00 - CA$319.00
CA$319.00
CA$319.00 - CA$319.00
CA$319.00

iOptron 10kg Counterweight for CEM120 (Low Latitude)

IOP-7326LL

10kg Counterweight Designed for iOptron CEM120 Mounts Optimized for use at latitudes below 10° Prevents collision with tripod or pier legs OEM iOp...

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CA$319.00 - CA$319.00
CA$319.00
CA$319.00 - CA$319.00
CA$319.00
iOptron 1kg Counterweight for SmartEQ
CA$39.00 - CA$39.00
CA$39.00
CA$39.00 - CA$39.00
CA$39.00

iOptron 1kg Counterweight for SmartEQ

IOP-3106-02

Weight: ~1 kg (2 lbs) Inner Diameter: 16.1 mm for SmartEQ shafts Outer Diameter: 78.6 mm Compatibility: iOptron SmartEQ & SmartEQ-Pro Mounts ...

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CA$39.00 - CA$39.00
CA$39.00
CA$39.00 - CA$39.00
CA$39.00
CA$97.00 - CA$97.00
CA$97.00
CA$97.00 - CA$97.00
CA$97.00

iOptron 2.5kg Counterweight for iEQ45, CEM40, GEM45, CEM60 and CEM70

IOP-8027-05

2.5 kg (5.5 lbs.) weight for precise balancing Fits 28.5 mm (1.12 in.) diameter counterweight shafts Compatible with iEQ45, CEM40, GEM45, CEM60, a...

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CA$97.00 - CA$97.00
CA$97.00
CA$97.00 - CA$97.00
CA$97.00
CA$77.00 - CA$77.00
CA$77.00
CA$77.00 - CA$77.00
CA$77.00

iOptron 2kg Counterweight for CEM26, GEM28 and AZ mount Pro

IOP-3006-05

2 kg (4.5 lbs.) weight for precise balancing Fits 20mm diameter counterweight shafts Official accessory for iOptron CEM26, GEM28, and AZ Mount Pro...

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CA$77.00 - CA$77.00
CA$77.00
CA$77.00 - CA$77.00
CA$77.00
CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00

iOptron 4.5kg Counterweight for iEQ30, ZEQ25, CEM25 and CEM40

IOP-3006-10

4.5kg (approx. 10 lbs) Weight Fits 20mm Diameter Counterweight Shafts Official Accessory for iEQ30, ZEQ25, and CEM25 Mounts Required for Balancing...

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CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00
CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$139.00
CA$139.00

iOptron 5kg Counterweight for iEQ45, CEM40, GEM45, CEM60 and CEM70

IOP-8027

Weight: 5 kg (11 lbs) Shaft Compatibility: 28.5 mm inner diameter Compatible Mounts: iEQ45, CEM40, GEM45, CEM60, CEM70 Locking Mechanism: M8 Locki...

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CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$139.00
CA$139.00
CA$223.00 - CA$223.00
CA$223.00
CA$223.00 - CA$223.00
CA$223.00

iOptron 9.5kg Counterweight for iEQ45, CEM60 and CEM70

IOP-7226
3 in stock

9.5 kg (20.9 lbs) Counterweight Balances Heavy Telescope & Imaging Payloads Compatible with iOptron iEQ45, CEM40, GEM45, CEM60, & CEM70 Mo...

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CA$223.00 - CA$223.00
CA$223.00
CA$223.00 - CA$223.00
CA$223.00
iOptron CEM26 CW Shaft Mounting House (Low Latitude)
CA$70.00 - CA$70.00
CA$70.00
CA$70.00 - CA$70.00
CA$70.00

iOptron CEM26 CW Shaft Mounting House (Low Latitude)

IOP-C26-CWSML

Enables low-latitude operation of the iOptron CEM26 mount Prevents counterweight shaft collision with tripod or pier Replaces the standard counter...

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CA$70.00 - CA$70.00
CA$70.00
CA$70.00 - CA$70.00
CA$70.00
iOptron CEM40 CW Shaft Mounting House (Low Latitude)
CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$139.00
CA$139.00

iOptron CEM40 CW Shaft Mounting House (Low Latitude)

IOP-C40-CWSML

Designed for the iOptron CEM40 Mount Solves Counterweight Shaft Collision at Low Latitudes Enables Unobstructed Meridian Crossing Essential for Eq...

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CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$139.00
CA$139.00

Balancing a Mount Properly

Good balance is not simply equal weight. Where the counterweight sits on the shaft changes the moment of inertia, which affects how the mount responds to guiding corrections.

  • Shaft diameter matching: Counterweight bores are mount-specific. A weight that nearly fits will either not seat or will mark the shaft, so the model matters more than the mass.
  • Weight position: A heavier weight close to the mount gives lower inertia than a light weight far out. Lower inertia generally responds better to guiding corrections.
  • Extension bars: Lengthen the shaft so a short heavy tube can be balanced with less total weight, reducing the load on the mount's bearings.
  • Declination balance: Balance in both axes, not just right ascension. Declination imbalance shows up as one-directional guiding error that is easily mistaken for backlash.
  • Slight east-heavy bias: A small deliberate imbalance keeps the gear teeth loaded on one face, which removes backlash effects in right ascension for many mounts.
  • Cable and accessory weight: A camera, filter wheel and cable bundle shift the balance point measurably, and balance should be set with everything attached.

Why Choose David Astro for Counterweights

A counterweight is a simple product with a mount-specific fit and a real effect on guiding.

  • Shaft diameter confirmed: We identify the correct bore for your mount rather than asking you to measure a shaft in the dark.
  • Balance technique advice: We explain how to balance in both axes with the full imaging train attached, including the deliberate east-heavy bias where it helps.
  • Extension bar sizing: For short heavy tubes we recommend an extension rather than more mass, which is easier on the mount and on you.
  • Authorized dealer: Genuine weights with manufacturer warranty, in Canadian stock.
  • Domestic shipping: Heavy items ship from Canada with no duties or brokerage fees for Canadian buyers.

Counterweights in Canada — Frequently Asked Questions

How much counterweight do I need?
Enough to balance with the weight roughly two thirds along the shaft, not at the far end. Sitting at the extreme end means you have too little mass and no adjustment range left.
Does counterweight position affect guiding?
Yes. A heavy weight close in gives lower rotational inertia than a light one far out, and lower inertia generally responds more crisply to guiding corrections.
Should I balance perfectly?
In declination, yes. In right ascension, many mounts guide better with a small east-heavy bias, which keeps the worm loaded against one gear face and removes backlash from the correction path.
Will any counterweight fit my mount?
No. Bore diameters vary between manufacturers and models. Tell us your mount and we will confirm the correct shaft size before shipping.

Balancing your rig?

Tell us your mount and payload and we will specify the weight and any extension. Held in Canada, shipped fast.