By the UK Telescope Mounts – Expert Reviews & Buyer's Guides Team · Updated May 2026 · Independent, reader-supported

How to Upgrade Your Dobsonian Rocker-Box for Motorised Tracking: UK Guide

A Dobsonian is fantastic value for aperture, but manual tracking is exhausting. After an hour of chasing objects across the eyepiece, your arms ache and you've drifted off target dozens of times. Motorised tracking solves this, keeping your target centred with minimal effort—transforming longer observing sessions and making astrophotography far more practical. Here's what UK observers actually have available to turn their manual Dobsonians into motorised ones.

Why Motorised Tracking Matters

Manual alt-azimuth tracking requires constant adjustment on both axes. On high magnifications, objects exit the field of view in seconds. For deep-sky observing, this means constant corrections. For planetary work and lunar imaging, it's nearly impossible. Motorised systems eliminate this friction, letting you focus on observation rather than hand-paddle gymnastics.

The challenge is that Dobsonians are simple—intentionally so. Adding motors means fitting hardware that doesn't come standard, and your chosen solution affects precision, cost, and ease of setup.

Sky-Watcher Dobsonian Motor Kits

Sky-Watcher offers factory-installed motor kits on their SkyDome and larger Dobsonians, and sell retrofit kits separately for existing mounts. These are the straightforward commercial route.

How they work: Two stepper motors (one for altitude, one for azimuth) mount directly to your rocker box. A hand controller connects via cable, offering speed adjustment and simple hand-paddle navigation. Recent kits include GoTo capability with computerised object location.

Pros:

• Purpose-designed for Dobsonians; no fabrication required
• Reliable stepper motors that hold position accurately
• Straightforward installation (2–3 hours for experienced users)
• Hand-controller doubles as a standard focuser paddle
• Wide availability through UK astronomy retailers
• Decent tracking accuracy for visual work and lunar/planetary imaging

Cons:

• Cost: typically £400–600 for a full kit installed
• Stepper motors aren't feedback-based; they can lose position if the scope is bumped hard
• GoTo models require star alignment before each session
• Power consumption from hand-paddle batteries is noticeable over long nights
• Doesn't suit observers wanting ultra-precise tracking for serious imaging

Best for: Visual observers wanting reliable, fuss-free tracking without engineering a solution from scratch.

Argo Navis Encoders

If you're serious about accuracy, Argo Navis shaft encoders represent the precision end of the upgrade spectrum. These are optical encoders that mount on the altitude and azimuth axes, reporting exact position rather than relying on motor steps.

How they work: Encoders read the scope's actual position fifty times per second. Paired with stepper motors and a capable hand controller (or GoTo system), they deliver sub-arcminute tracking repeatability. Argo Navis systems recalibrate in real-time, correcting for flexure, thermal effects, and mechanical play.

Pros:

• Exceptional tracking accuracy (< 1 arcminute reliably)
• Self-correcting: genuine feedback means the system knows where the scope actually is
• Works brilliantly for planetary imaging and long-exposure lunar work
• Modular: you can retrofit encoders to an existing motorised mount
• No special mechanical adjustments needed

Cons:

• Significant cost: full Argo Navis systems run £1,500–2,500 in the UK
• Steep learning curve; requires comfortable configuration experience
• Requires careful initial setup and collimation verification
• Power draw is higher than simple steppers
• Overkill for casual visual observers

Best for: Serious planetary and lunar astrophotographers who need reliability and won't tolerate positional drift.

OnStep: The DIY Path

OnStep is an open-source alternative that appeals to makers and electronics hobbyists. You assemble the electronics, program an Arduino or STM32 microcontroller, and add stepper motors plus encoders if you want them.

How it works: You build a control board, write configuration files, and integrate it with the motors on your Dobsonian's axes. The ecosystem supports WiFi hand controllers, smartphone apps, and even full GoTo capability with SkySafari or ASCOM.

Pros:

• Very cost-effective (£150–300 for a basic build, £600–900 with encoders)
• Highly customisable: you control every aspect of the software
• Supports encoders for feedback, improving accuracy progressively
• Active community; lots of builds documented online
• Learning experience: you understand your system intimately
• Works with any Dobsonian, regardless of manufacturer

Cons:

• Requires electronics competency; soldering, Arduino coding, troubleshooting
• Setup is genuinely involved (days, not hours)
• Support is community-only; no warranty
• Potential for fiddly calibration and alignment protocols
• Reliability depends on your soldering and configuration skill
• Overcomplicates ownership if you're not an electronics enthusiast

Best for: Tinkerers and builders who enjoy solving problems and want maximum features at minimum cost.

The Alternative: AZ-GTi

If you're open to replacing the entire mount rather than upgrading, Sky-Watcher's AZ-GTi is a computer-controlled alt-azimuth GoTo mount that works with scopes up to roughly 11 inches. It's motorised from the ground up, with GoTo control via smartphone app.

Why consider it: Plug-and-play simplicity, stellar GoTo accuracy, no upgrade labour required. Trade-off: you're investing in a new mount rather than enhancing what you've got.

Choosing Your Path

Go Sky-Watcher motor kits if you value plug-and-play reliability and don't mind spending for convenience.

Go Argo Navis if imaging is your primary goal and you can justify the investment for sub-arcminute accuracy.

Go OnStep if you're technically inclined, patient, and want maximum flexibility on a modest budget.

Go AZ-GTi if you're genuinely considering a fresh start.

Start by assessing your priorities: ease of installation, budget, accuracy demands, and whether you're imaging or viewing. Your Dobsonian's aperture and current condition matter too. A solid motorised rocker box transforms observing experience—the right solution just depends on how deep you're willing to go.

For a fuller comparison of GoTo-capable mounts and alt-azimuth systems, check our roundup guides to identify other options that might suit your setup.