Case study
A compact motor controller for a single-use surgical drill
How Pinetics designed a compact, cost-led BLDC motor controller and firmware for a single-use surgical drill, tuned to match the existing drill.
At a glance
Client
A US medical device company
Product
The BLDC motor controller board and firmware for a battery-powered, single-use surgical drill
Pinetics' scope
As quoted: hardware design, five prototype boards, bring-up, firmware, motor tuning, protection testing and handover
Outcome
Prototypes accepted by the client
What did the client need?
The client makes single-use surgical power tools, so every drill is built, sterilised and used once. They needed a new controller board and firmware for the drill’s Hall-sensor brushless motor. It had to fit the drill’s housing, cost little enough for a single-use product, drive the motor exactly as the existing drill does, and protect the user and the device if anything goes wrong.
What did Pinetics build?
- A new controller board sized to the drill’s housing, from architecture and component choice to schematic, layout and manufacturing files.
- Five prototype boards, assembled and brought up by Pinetics.
- Motor control firmware for the Hall-sensor BLDC motor, with speed and torque control across the drill’s full speed range.
- Protection features: fault detection, thermal management and electrical safeguards such as over-current and over and under voltage.
- Documentation and handover: firmware architecture and test reports, and support for the client’s move to manufacturing.
What was the hardest part of the project?
Four things pulled against each other. The board had to be small enough for the drill and cheap enough for a single-use product. It had to carry high motor current from the drill’s battery on that small board and get the heat out. The drill had to feel exactly like the existing one in the surgeon’s hand, across its whole speed range. And every protection had to fail safe.
How did the team solve it?
- A cost-led design. Component choices and the board layout were driven by the unit cost and the drill’s geometry from the first day, not trimmed at the end.
- Tuned to the existing drill. The team measured how the existing motor and controller behave, then tuned the new firmware until speed and torque matched.
What was the result?
The client accepted the prototype boards and firmware, delivered as quoted.
“We hired Pinetics to build the controller for our orthopedic surgical instruments. Precision, safety, and compliance were non-negotiable. They delivered on all three.”
CEO, US medical device company
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