Lacerta Dual-Speed Crayford Focuser Upgrade: Fine Focus on a Budget

Introduction

Most budget Dobsonians and many beginner telescopes ship with a basic single-speed Crayford focuser. It works well enough, but anyone who has chased perfect focus at high magnification knows the frustration of overshooting with every small turn of the knob. The Lacerta dual-speed Crayford focuser upgrade kit promises to fix that problem with a simple bolt-on conversion, and it does so for a fraction of the cost of replacing the whole focuser.

Why Upgrade a Standard Crayford Focuser?

A standard Crayford focuser uses a large wheel that presses a small axle against the focuser tube. Turning the wheel moves the tube in or out, but the spin ratio between the wheel and the axle is one-to-one. That means every rotation of the knob produces the same coarse movement, which makes precise focusing difficult when you are trying to nail critical focus on a planet or during astrophotography.

The accepted solution already exists: the dual-speed Crayford focuser, which pairs a large coarse wheel with a small fine-focus wheel, typically geared at around ten to one. The catch is price. Dual-speed focusers generally start around $200 and can reach $300 or more, which is a lot to spend on top of an already purchased telescope.

What the Lacerta Kit Does

The Lacerta upgrade kit adds a second, smaller fine-control wheel to an existing single-speed Crayford focuser. Once installed, the big wheel handles large coarse movements exactly as before, while the small wheel delivers very fine adjustments for critical focus. The result behaves like a genuine dual-speed focuser without replacing the entire unit.

The kit is made by Lacerta, an Austrian company whose name and lizard logo come from the Latin word for lizard, and it is distributed in the UK by 365astronomy.com, which charges 75 pounds for it. A used example can be found for considerably less; one was picked up in second-hand condition for $45, which underlines how much value this conversion can offer for patient shoppers.

Compatibility: Buy the Right Version

Lacerta makes a couple of different versions of this kit, and this one is designed specifically for the common Synta-made Crayford focuser often found on Orion and SkyWatcher Dobsonians. The mounting holes on this variant are spaced roughly 1.2 inches one way and 0.85 inches the other.

Before buying, measure your focuser and confirm you are ordering the correct model. Getting the wrong version is the most avoidable mistake in this whole process.

Installation: Simple Enough to Skip the Manual

Installation is genuinely straightforward. Remove the back panel of the focuser, which is held by four Phillips head screws, and pull out the focus-lock screw to keep it safe. Before attaching the kit, back off the tensioner set screw in the middle of the new unit using an Allen hex wrench so the axle is not jammed against the focuser tube while you tighten the mounting screws.

Once the kit is screwed in place, slowly tighten the tensioner in small increments until the tube has just the right amount of resistance. The process is simple enough that the instructions are barely needed.

Finishing Touches and Everyday Use

One clever detail: the kit includes a protruding shaft that matches the diameter of the standard focuser shaft, so the original coarse knob can be transferred over and secured with its set screw. The finished assembly looks slightly unconventional, with the original coarse knob on one side and the new fine knob nearby, but it works very well in practice. The focus-lock screw should be reinstalled afterwards, since it is genuinely useful when a heavy camera would otherwise make the focuser tube slide under its own weight.

In use, the big knob still gives familiar one-to-one coarse movement, while the small knob delivers that precise, slowed-down fine control that makes a dual-speed focuser so satisfying. Once you start using a dual-speed focuser, it is genuinely hard to go back.

Pricing and Where to Buy

New, the kit costs 75 pounds through UK distributor 365astronomy.com. Buyers in North America have another option: David Astro, a Canadian company, sells the same upgrade for $115 US plus shipping. Used units occasionally appear on astronomy classifieds at much lower prices, and patience can pay off here.

Whichever route you choose, the price sits far below the $200 to $300 entry point for a complete replacement dual-speed focuser, which is the core appeal of this product.

Is It Worth It?

For anyone still using a single-speed Crayford on a regularly used Dobsonian, this kit delivers the main benefit of a dual-speed focuser at a much lower cost. It installed easily on a spare focuser and then went onto an eight-inch Dobsonian used regularly, where coarse and fine control both worked as intended. The slightly odd two-knob-plus-shaft appearance is the only real cosmetic trade-off.

Conclusion

The Lacerta dual-speed Crayford focuser upgrade kit is one of those rare upgrades that solves a real observing frustration cheaply and easily. If your telescope still has a single-speed Crayford focuser and fine focus is a daily annoyance, this conversion lets you have the dual-speed experience without breaking the bank.