Side milling cutter duo enables long tool life and shorter processes

Pressure arms are the force generators in folding machines on which profiles of various types and shapes are bent. They are used in architecture, the automotive industry, and many other sectors. For example, for the frames of TV monitors, for stair profiles, flashings and yes, even for a simple gutter with a bead.

The machining process for such pressure arms includes, among other things, milling a groove with L/W/D = 1200 x 24 x 5 mm. This groove later incorporates the measurements for determining the exact position of the pressure arm. A very precise milling operation, but one that requires a 250 mm cantilever of the tool. The current solution with a side milling cutter (8 teeth, Ø 80 mm, a_p = 3 mm and a_e = 5 mm) roughs and finishes the groove in a mere 25 minutes.

Basically, the customer is very satisfied with the current situation. However: A bending machine always requires two of these pressure arms with groove. The running time for all operations is two hours, so you can produce exactly four components in an 8-hour shift … but too often you only manage three parts. The process must therefore be quicker.

And Swiss colleague Raphael Nobs at Dihawag literally had his ear in the right place. The customer had tried to gain time by using a wider cutting edge. However, increasing the cutting width from 3 to 5 mm proved to be impossible to realise. Excessive vibrations due to workpiece behaviour that is too unstable for these compressive forces. The workpiece quality was no longer consistent, and the sound during machining did not convey the feeling that the process was stable and secure. This did not increase productivity.

Now Nobs and Sturm were able to make the most of the advantages of the polished, highly positive AVANTEC tool edges. For operations with long tool cantilever, vibration-free milling is simply the key to a safe process. It was agreed: Together with the staggered tooth arrangement of a TB18 side milling cutter, the groove can be produced more productively on this soft-cutting basis.

Two weeks later, the TB18s milled in tandem. One roughs first, then the other finishes with the same type of indexable insert. The operations are split between two tools due to the very different stresses (roughing a_e = 6 mm, finishing a_e = 0.4 mm) so that both operations run optimally with their fixed parameters. The tool life for roughing has increased from 5 to 11, and for finishing, from 5 to 25 workpieces. The AVANTEC solution with the TB18 duo is a good 30 minutes faster, so that the four pressure arms come off the machine in one operation – every time. It’s worth listening, and listening carefully!

Raphael Nobs – at Dihawag AVANTEC solution finder on-site for Switzerland

Emanuel Sturm – for the past 11 years solution finder for Switzerland and Baden-Württemberg

TB18 with right and left hand insert system
Double cutting depth and very smooth, silent running