Tool breakage is one of the most disruptive events in a CNC machining environment. When a cutter fails mid-job, the consequences ripple fast — scrapped parts, unplanned downtime, and in serious cases, damage to the machine itself. Most manufacturers manage this reactively, replacing tools on a schedule rather than on condition, because until now there hasn’t been a practical way to know what’s actually happening at the cutting edge.
SmartMill changes that.
What SmartMill Does
SmartMill is a miniature wireless sensor system that fits directly inside a standard CNC tool holder. It monitors vibration and temperature at the point of cutting — continuously, in real time, without any modifications to your machine or your process.
Data is transmitted wirelessly to a connected device, where it can be logged, visualised, and analysed. The system is designed to give manufacturers the information they need to move from time-based tool replacement to condition-based tool management — cutting waste, reducing unplanned stops, and giving engineers genuine visibility of what’s happening inside the spindle.
Built for the Real World
Developing a sensor system for the inside of a rotating tool holder is not a trivial engineering challenge. The environment is demanding: high rotational speeds, coolant exposure, and a form factor measured in millimetres.
We designed and manufactured a custom PCB stack small enough to fit inside a 25mm diameter tool holder, built the embedded firmware to acquire and process sensor data on the device itself, and validated the system through an extensive programme of real-world machining trials at the University of Huddersfield. The device has been tested at speeds up to 8,000 RPM and demonstrated reliable wireless data transmission throughout.
Developed with Innovate UK Support
SmartMill was developed with funding from Innovate UK’s Advanced Machinery Innovation Fund, in partnership with the University of Huddersfield. That collaboration brought together Digital Transit’s embedded systems and product development expertise with Huddersfield’s machining research capabilities — and the result is a prototype that demonstrates the real potential of in-spindle condition monitoring.
What’s Next
We’re continuing to develop SmartMill towards a production-ready system and are actively looking to work with manufacturers who want to be part of that journey.
If you’re interested in what SmartMill could do for your operation, get in touch.