For years, CNC machinery has been the benchmark for precision in industrial machining. However, the evolution of robotics — especially refurbished robots equipped with high‑performance spindles — is reshaping the landscape.
More and more factories are now asking themselves:
Is it really worth replacing a CNC with a robotic milling cell?
The answer depends on ROI, but calculating it correctly requires looking beyond the initial price.
Why many factories are reconsidering their investment
In the past, the decision was based almost entirely on machining precision and speed. CNC machines offered rigidity, reliability, and millimetric accuracy.
But today’s refurbished industrial robots — from brands like KUKA, ABB, FANUC, or Yaskawa — are reaching accuracy levels more than sufficient for roughing, prototyping, or complex mold machining, and at a significantly lower cost.
In addition, modern production lines demand flexibility, something difficult to achieve with a fixed CNC machine.
A single robot equipped with a spindle can:
- mill an aluminum part,
- polish resin molds,
- change tools,
- or even switch to handling tasks within the same cell.
This adaptability is precisely what is redefining ROI.
How to calculate the real ROI of a robotic system
ROI (Return on Investment) measures how long an investment takes to recover its initial cost.
In automation, it is usually expressed as:
But when comparing robots with CNC machines, five key variables must be included:
- Acquisition cost
- A refurbished robot with a spindle can cost 40%–60% less than a new CNC machine.
- Productivity and cycle time
- Robots can operate extended shifts or 24/7 without constant operator presence.
- Energy consumption
- A 6‑axis robot typically consumes 30–40% less energy than an enclosed CNC machine with active cooling.
- Maintenance and spare parts
- Spindles are easy to replace; refurbished robot components are cost‑effective and globally supported.
- Flexibility and reuse
- A robot can be reprogrammed for a different task, extending its useful life beyond the original project.
When these variables are properly evaluated, the typical ROI of a robotic milling cell can be achieved in under 18 months — compared to the 3–5 years common with CNC machines.
Real example: From fixed CNC to flexible robot
A polyurethane mold manufacturer in Italy — a Eurobots customer — was facing high maintenance costs on its 5‑axis CNC.
They decided to replace it with a refurbished KUKA KR 210 fitted with an HSD ES951 spindle.
- Initial investment: 45% lower
- Cycle time: reduced by 25%
- Annual energy savings: 32%
- ROI achieved: 14 months
Moreover, the robotic cell was later adapted to mill wood and composite materials — something impossible with the previous CNC.
The customer not only saved money, but gained production versatility without compromising surface quality.
ROI is more than a formula
Replacing a CNC with a robot isn’t a trend — it’s an industrial strategy to reduce costs, increase flexibility, and extend the lifespan of production assets.
Calculating real ROI must include parameters that reflect the new reality of smart manufacturing: energy consumption, reprogramming, footprint optimization, and maintenance.
Robotics doesn’t replace precision — it redefines it.
And in doing so, ROI becomes more than a static number: it becomes an evolving competitive advantage.