Custom Motors for Precision Motion Control

When do they make sense? Q&A with PI's Dietrich Wins

Q: Electromagnetic motors seem like a commodity today. Why would PI spend resources to develop their own motors?

A: This is mostly correct.  PI’s vertical integration philosophy means developing high precision key technologies in-house.  Less critical off-the-shelf components are sourced from our qualified long-term partners.  This includes a variety of electro-magnetic linear and rotary motors. However, when our customers come to us with special requirements, we sometimes have to go a different route. PI has a long history of designing special electrodynamic drives, from voice coil actuators to 6-axis magnetic levitation systems.

Having the experience and capability to develop prototypes and custom systems quickly for uncommon needs (size, form factor, force, precision, dynamics, etc.) has great benefits to our customers. For most standard products, PI will continue to work with world leading motor suppliers.

Q: Can you provide a few examples where customization makes sense?

A: The focus of our work is not limited to the motor itself, but the entire positioning solution including the guiding system, encoder, controller, and other components. For the best overall performance, a customized motor allows more design freedom. More often than not, this is the case when geometric requirements cannot be met with off-the-shelf motors.

Q: Which type of motors are designed and manufactured at PI?

A: In addition to piezoelectric ceramic motors, where PI plays a global leading role, PI can model, design and build voice coil, ironless and iron-core electrodynamic linear motors as well as a variety of torque motors.

Q: What applications are targeted with custom technologies?

A:Voice coil motors are ideal for optical scanning applications with ranges from a few mm to about 1 inch, these are also often used for fast nano-focusing in life science and surface metrology applications.  Other applications for voice-coil motors are fast tip/tilt steering mirrors with a few degrees of rotation. Miniaturized motors can be used in medical endoscopes. 3-Phase linear motors are used in high precision actuators and long travel custom linear stages for inspection and automation applications. Hollow shaft motors are used in optical transmitted light applications.

Q: How long does it take to develop a custom system?

A: It depends on the complexity. We can typically provide prototypes in a few weeks or even faster. Another advantage of our customization capability is that we can optimize the motor along with the rest of the motion control system during the design phase from the first prototype to the pilot series for our customer. This results in a better performing product that can be offered at a lower price - both critical parameters for OEM customers.