Losmandy OPW-11/W One-Piece Worm Block with Worm

Product Overview

The OPW-11/W is a Losmandy one-piece worm block supplied complete with the worm. It uses precision bearing blocks in a 7075 aluminium housing, an all in-line motor and gearbox worm design, preloaded bearings and screw-adjusted worm gear mesh.

Who It's For

This is the complete assembly. Worm and block wear against each other, so they usually need replacing together — a new worm bedding into tired bearings will not hold the mesh you set. It is also the clean way to convert an older two-piece bearing-block axis to the one-piece design in a single job.

Key Features & Design

• Worm included.
• Precision bearing blocks in a 7075 aluminium housing.
• All in-line motor and gearbox worm design.
• Preloaded bearings.
• Screw-adjusted worm gear mesh.

Mechanical Design

Backlash in a Losmandy axis has two sources: the mesh of worm against gear, and play in the worm between its own bearings. The one-piece block addresses both at once. Mesh is set with a screw rather than by loosening the outer bearing block and pivoting the worm into the gear by hand, and the bearings arrive preloaded so the worm has no free movement to start with.

Because the worm comes with the block, the pair is matched from new. That is what separates a rebuild from a patch: the mesh you set on assembly is the mesh the axis keeps, rather than one that drifts as a new worm wears into old bearings.

Recommended Uses

Rebuilding a worn RA or DEC axis to specification. Converting an older two-piece bearing-block axis to the one-piece design. Curing backlash that mesh and clutch adjustment no longer fix. Keeping a complete spare assembly for a mount in heavy or remote use.

Compatibility and Accessory Notes

• Which block fits your mount depends on the axis and its vintage. Tell us your mount model, which axis you are working on, and whether it has tucked or non-tucked motors, and we will confirm the correct block before you order.
• Without the worm: the OPW-11 is the same block for owners who already have a good worm.
• Worm alone: the high-precision brass worm is stocked separately.
• Older design: the worm bearing blocks, set of 2 serve a two-piece axis.
• Motor coupling: the G11 and GM8 motor-to-worm couplings.

Good to Know Before You Order

• Fit depends on your axis, not just the mount name. Send us the mount model and axis and we will confirm the right block.
• This is an internal mechanical part. Fitting it means opening the axis, with the mount manual alongside. We are happy to talk it through first.
• If your worm is in good order, the OPW-11 without a worm costs less and does the same job.
• Losmandy publishes no weight or dimensions for this part.
• Specifications are Losmandy's published figures.

Frequently Asked Questions

Is it difficult to set up?

It is an internal repair. The motor and worm cover come off, the old assembly comes out, this goes in, and the mesh is set with its adjustment screw.

Does it include the worm?

Yes — that is what the /W denotes.

Will it fit my mount?

Tell us the mount model, the axis and whether the motors are tucked or non-tucked, and we will confirm.

How do I know the block is worn rather than the mesh?

Backlash that comes back after you have set the mesh, or play you can feel in the worm between its bearings, point at the block. Describe what you are feeling and we will help identify it.

What does the one-piece design change?

Mesh becomes a screw adjustment, and the preloaded bearings remove play in the worm.

Bottom Line

In short: a complete one-piece worm block with the worm included, 7075 aluminium housing, preloaded bearings and screw-adjusted mesh — the assembly that brings a worn axis back to specification.