Band saws are slow. They produce one board per pass, need skilled operators to keep them running straight, and struggle with small-diameter logs. For sawmills processing softwood and hardwood, that’s a bottleneck you can’t afford.
The up and down multi blade saw – a double-shaft circular rip saw – was built to solve this. Two spindles, one upper and one lower, carry multiple saw blades that cut a round log into several finished boards in a single pass. Less blade contact, less friction, less heat. And because the blades run cooler, you can use thinner ones – which means narrower kerf, less waste, and higher yield.
This article covers how the machine works, what makes the double-shaft design different, and what to look for when choosing a model.
What Is an Up and Down Multi Blade Saw?
An up and down multi blade saw is a double-shaft circular rip saw that uses two spindles – one upper and one lower – to cut round logs into multiple boards simultaneously. It is also known as a round log multi blade saw, gang rip saw, or log slabbing machine.
Working Principle
The log is fed longitudinally into the machine through a stable feeding system. Inside the cutting chamber, two sets of circular saw blades – mounted on the upper and lower spindles – engage the log at the same time. The upper spindle can be raised or lowered to accommodate different log diameters, while the lower spindle remains fixed. Each blade cuts a separate board, and the result is one log transformed into multiple finished boards in a single pass, with dimensional accuracy controlled within ±0.5mm.
Single-Shaft vs. Double-Shaft: What Is the Difference?
Multi blade saws can be divided into two main types based on their working method: single-shaft and double-shaft. Double-shaft machines can be further divided into up-down, left-right, and front-back configurations.
Single-shaft structure: One set of saw blades on a single spindle. Typically used for cutting square timber or edge trimming, where the material is already relatively small. The blades used are thinner, which improves yield.
Double-shaft structure: Two sets of saw blades on two spindles, working simultaneously in the same vertical or horizontal plane. The blades contact the wood less, reducing friction and load on the saw. This allows the use of thinner blades, higher yield, and less risk of blade burning.
Why up-down is the most common configuration for square timber: The up-down spindle arrangement uses smaller-diameter, thinner blades. This makes it possible to process large-diameter logs while reducing energy consumption and kerf loss. The cutting surface is smoother, and the front and rear drive shafts provide smooth, automatic feeding.
Key Features of the Up and Down Multi Blade Saw
Double-Shaft Construction
The upper and lower spindle design is the defining feature of this machine. By distributing the cutting load across two spindles, each blade does less work, generating less heat and friction. This allows the use of thinner blades – which means narrower kerf, less wood waste, and higher yield.
Heat-Treated and Dynamically Balanced Spindles
Both spindles undergo heat treatment, straightening, and hardening. Each spindle is dynamically balanced to ensure stable operation at high speeds. The spindle core features an internal water spray design, making the machine suitable for both dry and wet cutting applications.
Thin Kerf Blades for Higher Yield
The machine uses imported alloy thin-kerf blades with high precision. There is no “size difference” problem between blades – the cutting surface is smooth and requires no additional planing. This reduces processing steps and improves wood utilization.
Cooling and Dust Removal System
A dedicated cooling and dust removal system keeps the blades from operating at high temperatures for extended periods. This extends blade life and reduces dust in the working environment.
Active Material Separation at the Outlet
The discharge end is equipped with an active material separation and guiding device. This prevents boards from jamming the blades and ensures smooth, continuous feeding.
High-Low Pointed Chain Feeding
The feeding system uses a high-low pointed chain design – simple, economical, and easy to maintain. The feeding speed is controlled by frequency conversion, allowing convenient adjustment for different materials and dimensions.
Centralized Lubrication
The spindle box guide rails and feeding guide rails are lubricated by a manual pump system, extending the service life of the guide rails and reducing maintenance frequency.
Fully Enclosed Safety Design
The transmission and saw blades are fully enclosed. This significantly improves safety compared to band saws, where the blade and transmission are exposed during operation.
Technical Specifications
| Model | CRS200 | CRS250 | CRS300 | CRS350 | CRS400 | CRS500 |
|---|---|---|---|---|---|---|
| Cutting Length (mm) | 450–4000 | 600–4000 | 600–4000 | 800–4000 | 800–4000 | 800–4000 |
| Cutting Diameter (mm) | 60–200 | 80–250 | 150–300 | 150–350 | 200–400 | 300–500 |
| Saw Blade Size (mm) | 305×2.6 | 366×3.0 | 410×3.6 | 480×4.2 | 550×4.8 | 650×6.5 |
| Saw Blade Speed (r/min) | 3800 | 3800 | 3800 | 3980 | 3980 | 3980 |
| Spindle Power (kW) | 22×2 | 30×2 | 37×2 | 37×2 | 45×2 | 55×2 |
| Frequency Control (m/min) | Adjust | Adjust | Adjust | Adjust | Adjust | Adjust |
| Capacity (m³/h) | 2–3 | 4–5 | 5–6 | 6–7 | 7–8 | 10–12 |
| Weight (kg) | 1700 | 2200 | 3000 | 3300 | 3500 | 3800 |
| Dimensions (mm) | 3340×950×1400 | 3600×950×1500 | 3800×1200×1650 | 3800×1300×1750 | 3950×1360×1800 | 4000×1400×1800 |
The model range covers cutting diameters from 60mm to 500mm and cutting lengths from 450mm to 4000mm. Capacity scales from 2–3 m³/h for smaller operations up to 10–12 m³/h for large-scale production. All models feature frequency-controlled feeding and dual-spindle power configurations ranging from 22kW×2 to 55kW×2.
Applications
Construction & Scaffolding Planks
The construction industry requires large volumes of dimensional lumber for formwork and scaffolding. The up and down multi blade saw converts round logs into construction-grade boards at high throughput, with tolerance within ±0.5mm. The double-shaft design ensures smooth cutting surfaces that meet strict construction requirements.
Pallet & Packaging Wood
Pallet manufacturing demands consistent, accurately dimensioned boards for decks, stringers, and blocks. The double-shaft multi blade saw produces boards with smooth surfaces that can be used directly without further planing. The ability to process small-diameter logs (from 60mm) maximizes raw material utilization.
Furniture & Flooring Panels
For furniture and flooring production, the machine serves as the primary breakdown equipment. It handles diameters from 60mm to 500mm and can produce different board thicknesses by adjusting blade spacing. The high precision of the cut reduces the need for subsequent planing and sanding.
Other Applications
Wooden packaging crates
Finger-joint and blockboard core
Pencil slats and small wooden parts
How to Choose the Right Model
Selection depends on two main factors: log diameter and required output.
Small logs (60–200mm): CRS200 – 2–3 m³/h
Medium logs (150–350mm): CRS300 or CRS350 – 5–7 m³/h
Large logs (200–500mm): CRS400 or CRS500 – 7–12 m³/h
For high-volume production, choose a model with capacity slightly above your downstream processing limit to avoid bottlenecks. Also consider the blade configuration – the number of blades and their spacing determine the board thicknesses you can produce.
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