Losmandy OPW-8/W-ORIG One-Piece Worm Block with Worm — Stainless Bearing Block

Product Overview

The OPW-8/W-ORIG is a Losmandy one-piece worm block supplied complete with the worm, built with a precision stainless steel bearing block in a 7075 aluminium housing. Like the rest of the range it uses an all in-line motor and gearbox worm design, preloaded bearings and screw-adjusted worm gear mesh. The stainless bearing block is what distinguishes it from the standard OPW-8/W.

Who It's For

This is the version for an axis that wants the stainless bearing block rather than the standard one. Losmandy lists it separately and prices it well above the standard assembly, which is the clearest signal of what it is: a specific build for a specific axis, not a general upgrade. It is the part to order when your axis is the one that takes it.

Key Features & Design

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

Mechanical Design

The one-piece block turns mesh adjustment into a screw setting rather than the older routine of loosening the outer bearing block, pivoting the worm into the gear by hand and re-checking that it still turns freely. Preloaded bearings take out the second source of backlash, play in the worm between its own bearings, so that the mesh you set is the mesh you keep.

The stainless bearing block is the difference here. Steel is stiffer than aluminium and dimensionally steadier as temperature changes across a night, which is what a bearing seat is being asked to do — hold the worm's position while everything around it moves a little.

Recommended Uses

Rebuilding an axis that takes the stainless bearing block. Replacing a worn worm and block together as a matched assembly. Keeping a complete spare for a mount in remote or observatory use where downtime is expensive.

Compatibility and Accessory Notes

• Confirm this is the right block before ordering. The OPW range covers several axes and vintages, and this is the stainless-block build. Tell us your mount model, the axis and whether the motors are tucked or non-tucked, and we will check it against Losmandy's parts data for you.
• Standard build: the OPW-8/W is the standard-bearing-block assembly, also supplied with a worm.
• Without a worm: the OPW-8 is a block for owners who already have a good worm.
• Worm alone: the high-precision brass worm is stocked separately.
• Motor coupling: the G11 and GM8 motor-to-worm couplings.

Good to Know Before You Order

• This is the most expensive block in the range, and deliberately so. If your axis takes the standard block, the OPW-8/W does the same job for considerably less — ask us which one your mount needs rather than ordering on the part number alone.
• Losmandy lists this item on a waiting list from time to time. Availability can be slower than the standard block; we will tell you where it stands when you enquire.
• This is an internal mechanical part. Fitting it means opening the axis, with the mount manual alongside.
• 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 rather than an accessory fit: the motor and worm cover come off, the assembly is exchanged, and the mesh is set with its adjustment screw.

What makes this different from the standard OPW-8/W?

The bearing block is precision stainless steel rather than the standard material. Everything else — the 7075 housing, the in-line design, the preloaded bearings, the screw-adjusted mesh, the included worm — is common to both.

Is it an upgrade for any mount?

It is a specific build rather than a universal upgrade. Send us your mount details and we will tell you whether it is the block your axis takes.

Does it include the worm?

Yes.

Why is it so much more expensive?

It is a different build at a different price from Losmandy. If the standard block suits your axis, that is the cheaper and equally correct answer.

Bottom Line

In short: a one-piece worm block with a precision stainless steel bearing block and the worm included, in a 7075 aluminium housing with preloaded bearings and screw-adjusted mesh — the specific build, worth confirming against your axis before you order.