On March the 17th, the company PM had invited us for an excursion to their facility. The day started with us gathering at the usual spot, next to the TUDelft library. At 10:45 our drive to Dedemsvaart begins. Upon arrival, a group picture is taken and we register ourselves at the entrance.

Together with the provided lunch, a presentation is given about PM’s main business. PM makes precise (Linear) bearings, which they sell in a combination of custom-made and standard models. We are told about the complex process that is used to manufacture these bearings, from buying the raw materials to the heat treatment and eventual final product.

After this short and informative presentation, we start with, in my opinion, the most interesting part of the day, the company tour. Our large group is split into 3 smaller groups each with different guides. My group got the most experienced tour guide, manufacturing engineer Wim Finkers, who has worked at PM for 34 years. He took us on our tour to the CNC mills, grinders, ovens, and the cleanroom. Where he showed us what the bearings looked like at each process, he also showed us some of their recent expansion in both spaces (New work halls) and new technologies.

With this, the tour ended and we moved on to the final part of the day, a case study. A Z-stage shows a repeatable history-dependent rotation error, two compression springs are present as gravity compensation. They also gave us the information that the use of tension springs removes this error. Some creative causes were discussed, such as the Coriolis effect and eddy currents of the actuator, but in the end, the team which thought of the rotation or buckling of the spring won. They got the PM logo placed on (short) linear guides and the team “ slinky” won keychains for the best name.

With this, we made our way back to the bus and started the long drive back to Delft during rush hour. The company tour was really interesting and introduced me to a company and an important focus of hi-tech that I was not yet familiar with. Although the distance from most other companies (and Delft) probably does not make it the first choice for everyone it is still worth checking out.

– Thomas Peeters