Maximising Multi-Pallet CNC Productivity: Insights from 1st MTA Engineers

Multi-pallet CNC machines, particularly horizontal configurations, are among the most powerful tools a manufacturer can use to boost throughput, reduce labour costs, and optimise spindle utilisation. Yet, achieving maximum productivity is not just about installing a pallet pool or adding automation—it requires careful consideration of workholding, fixture design, and operational strategy.

At 1st MTA, our engineers Steve Ellicott (Technical Sales Manager) and Roy Wyatt (Technical Manager) have extensive experience helping manufacturers get the most from their multi-pallet systems. This article explores why spindle utilisation gains of 85–95% are achievable, and why multi-part workholding and smart fixture design are often the difference between theoretical and real-world productivity.

Why Multi-Pallet Machines Matter

Traditional single-pallet machines often run at 20–30% utilisation, largely limited by downtime for loading, unloading, and setups. Multi-pallet systems overcome these bottlenecks:

• Unmanned “lights-out” operation: Machines can run overnight or through weekends, increasing production without additional labour.
• Reduced setup time: Operators can load/unload parts on one pallet while the machine continues cutting on another.
• High spindle utilisation: Automated pallet pools keep the spindle cutting almost continuously.
• High-mix, low-volume flexibility: Multiple parts or jobs can be scheduled across pallets, optimising machine use for complex operations.

Twin-pallet systems double capacity compared to single-table machines, while pallet pools with 6–20+ pallets allow long-term unattended operation. With proper workholding and scheduling, these systems often deliver 3–4× more productive spindle time from the same machines.

Workholding: The Key to Unlocking Productivity

While multi-pallet machines provide the hardware potential, workholding determines whether that potential is realised. Poorly chosen fixtures can create bottlenecks that reduce spindle utilisation and limit lights-out operation.

Key considerations for multi-pallet workholding include:

1. Precision and repeatability: Zero-point systems allow sub-30-second pallet changes with micron-level consistency, keeping parts aligned across multiple operations.
2. Access and clearance: Fixtures must allow full tool access, especially on 5-axis machines, to avoid collisions and minimise multiple setups.
3. Material and geometry constraints: Thin parts require distributed, gentle support; irregular geometries may need bespoke soft jaws or fixture modifications.
4. Production volume strategy: High-density setups like tombstones and multi-part vices maximise the number of parts per pallet, reducing the frequency of loading cycles.
5. Rigidity and stability: Fixtures must withstand high machining forces to avoid chatter, vibration, or scrap.
6. Automation readiness: For robotic tending, pallets and fixtures must allow automatic clamping and unclamping without human intervention.
7. Operator ergonomics and safety: Loading/unloading must be simple and safe, with sufficient space for chip clearing.

Multi-Part Workholding vs Single Vices

A common mistake in multi-pallet setups is relying on single-station centric vices. According to Steve Ellicott:

“Using a single vise on a multi-pallet machine is inefficient. To maximise productivity, use multi-part workholding—such as Chick MultiLok, OK Vise, SINCO, or bespoke cube/tombstone fixtures.”

The benefits of multi-part workholding are substantial:

• Fewer tool changes, saving significant time
• Higher parts per cycle, even when operations increase
• No cut allowance loss, maximising material efficiency
• Greater adaptability, enabling lights-out production with multiple jobs

Roy Wyatt adds:

“Most manufacturers aren’t running full simultaneous 5-axis work on multi-pallet machines—it’s often 3+2. In these setups, multi-part fixtures deliver the most benefit.”

Productivity gains with multi-part fixtures are often measurable: single-vises typically achieve 30–35% utilisation, while tombstone or cube fixtures can reach 85–95%, representing a 50–55% increase in throughput per spindle.

Common Workholding Mistakes That Reduce Productivity

Even with multi-pallet systems, common mistakes can dramatically reduce efficiency:

1. Ignoring repeatability – Re-probing offsets increases downtime.
2. Low part density – Frequent pallet changes interrupt lights-out operation.
3. Poor tool access – Bulky fixtures restrict spindle paths, forcing extra setups.
4. Over-clamping thin parts – Distortion or scrap can result.
5. Underestimating rigidity – Vibration reduces tool life and surface finish.
6. Ignoring chip evacuation – Chips trapped in fixtures cause inaccuracies.
7. Not planning for automation – Robotic loading requires compatible fixture design.

Engineering Insights from 1st MTA

• Steve Ellicott: “Better results come from cube or tombstone fixtures using Chick MultiLok, OK Vise, SINCO, or bespoke designs.”
• Roy Wyatt: “3+2 axis machining benefits the most. Multi-part workholding allows more parts per cycle, even with additional operations.”

The combination of multi-pallet machines, multi-part workholding, and rotary tables represents a strategic upgrade path for modern manufacturers, balancing efficiency, flexibility, and reliability.

Visualising the Gains

• Single vice: 30–35% utilisation, frequent tool changes, limited parts per cycle
• Multi-part fixture (Cube/Tombstone): 85–95% utilisation, fewer tool changes, significantly higher parts per cycle

The infographic demonstrates real, quantifiable productivity improvements achievable when engineers design fixtures to maximise density and accessibility.

Conclusion

Maximising multi-pallet CNC productivity isn’t just about machines—it’s about smart workholding, fixture design, and automation readiness.

By adopting multi-part workholding, zero-point clamping, and flexible systems, manufacturers can:

• Reduce setup times
• Increase parts per cycle
• Enable lights-out production
• Realise 3–4× more effective spindle utilisation

Workholding is no longer just a supporting element—it is central to achieving the full potential of multi-pallet CNC machines.

Maximising Multi-Pallet CNC Productivity