Precision Loading and Micron-Level Machining with FANUC Solutions

Hembrug’s established MikroTurn and MikroTurnGrind series machines feature hydrostatic technology that enables wear-free operation of the spindles and slides, helping to maintain accuracy for more than 25 years. However, when developing its latest MikroTurn Twin, a machine for turning hard components using two spindles, the company knew its design would necessitate an extra factor for consideration: automation. 

Engineering Manager Bart de Wolf takes up the story: “The challenge here is that we designed a machine for high-volume machining, where every second counts, and wanted to perform the loading and machining of parts simultaneously. The concept involves two main spindles that facilitate component machining on one spindle while using a robot to unload/load another part on the second spindle.” 

As typical for Hembrug machines, there could no compromise in precision. Machines built by the company typically attain dimensional tolerances of ≤2 µm, roundness of ≤0.5 µm and Ra (surface finish) of 0.1-0.4 µm. Similarly, the MikroTurn Twin had to serve as a high-quality platform suitable for micron-level precision machining.  

The solution arrived in the form of a FANUC Series 32𝑖-Model B Plus CNC with FANUC PANEL 𝑖H Pro industrial PC, and a FANUC LR-10𝑖A/10 compact 6-axis industrial robot. 

Bart de Wolf continues: “We have nearly 20 years of experience with FANUC, mainly for CNC controls, but also in recent years with FANUC robots and their integration into complete turnkey solutions.” 

For its MikroTurn Twin, Hembrug had to define very precise machining paths from the FANUC CNC, while simultaneously ensuring the FANUC robot loads/unloads components reliably and accurately. There cannot be any misalignment of workpieces in the chuck, even by 1 or 2 µm. 

“With the FANUC robot control, we found an effective solution to help meet our objectives,” says de Wolf. “An important challenge and development point for us was to optimise both the CNC and PLC for the MikroTurn Twin’s machining processes. By adopting FANUC solutions we knew we could create highly accurate contours while also providing a flexible set up to meet varying customer demands. It all resulted in a satisfying and robust outcome.”