SCS Linear Bearing Blocks for Supported Round Rails

SCS linear bearing blocks are the sliding units that ride along a supported round rail, carrying a gantry, spindle carriage, or print head smoothly along one axis of a machine. The range covers bore sizes from 8mm up to 20mm, so the same basic block design matches shaft diameters used on light 3D printers and heavier CNC router frames.

Anyone building a machine from aluminium extrusion or plate, or repairing a worn slide on an existing router, will recognise this part by its boxy aluminium body and two mounting holes. It is a common component, interchangeable across many designs as long as shaft diameter and bolt spacing match.

Details / Specifications

Dimensions, data and technical drawings are provided with reasonable care. Minor deviations may occur due to production batch, without affecting quality.

Features of SCS Linear Bearing Blocks

SCS linear bearing blocks combine a sealed ball bearing with a cast aluminium housing, keeping moving mass low while still supporting real cutting or printing loads. The bearing rides directly on the polished shaft, so once the fit is correct there is no perceptible play in the block.

The mounting pattern is drilled and tapped at the factory, so the block bolts straight onto a plate or extrusion bracket without extra machining. Because the housings across the range share a similar shape, swapping bore size mostly means matching block width to the rail spacing already built into the frame.

• Sealed linear ball bearing built into the housing
• Lightweight cast aluminium body
• Pre-drilled mounting holes on a standard bolt pattern
• Available for round shaft diameters from 8mm to 20mm
• Smooth sliding motion with minimal play once correctly fitted

Where It’s Used

SCS linear bearing blocks are the standard support for the X, Y and Z axes of a CNC router built around round supported rail rather than profile rail. They also appear on 3D printer gantries, laser engraver carriages, and DIY linear stages where a shaft and two end supports replace a full linear guide profile.

Builders assembling a complete axis often pair the block with matching round rail, shaft end supports and a leadscrew or belt drive from the same supplier; the full range of CNC linear motion parts is available at torgoscnc.gr/en/shop. Workshops repairing an older machine typically replace only the block, since the shaft and supports usually outlast the bearing inside.

What to Check Before Buying SCS Linear Bearing Blocks

Bore size is the first thing to confirm: an 8mm block will not run on a 12mm shaft, and forcing the fit damages both parts. Measure the shaft with calipers rather than guessing from the machine’s age or brand, since rail diameters vary between manufacturers.

When choosing SCS linear bearing blocks, check the mounting hole spacing against the bracket or plate the block will sit on, and confirm whether the axis needs a standard block or a longer, flanged version for rigidity. A block undersized for the load it carries tends to show play sooner on a Z axis carrying a spindle.

Installation and Maintenance

Slide the block onto the shaft before the shaft is bolted into its end supports, since most SCS housings are closed and cannot be fitted afterwards. Tighten the mounting bolts evenly, then check that the block travels the full length of the shaft without binding before loading the axis.

The bearing inside is a type of linear-motion bearing, and like any ball bearing it runs better with a light film of lithium grease on the shaft rather than dry. Wipe off dust and swarf regularly on a router cutting wood or MDF, since fine particles accelerate wear.

FAQ

What does the number after SCS mean? It states the bore diameter in millimetres, so an SCS12 block fits a 12mm shaft, with block bodies scaling up across the range.

Can two different block sizes be used on the same shaft? No, both blocks on a shaft must match its diameter exactly, since the bearing bore is fixed to one shaft size and cannot adapt to another.

Do SCS blocks work with profile rail instead of round shaft? No, they are built for supported round rail only; profile rail systems use separate carriages and guide blocks not interchangeable with this series.