Fast and documented measurements of hobs with carbide inserts

Parametrised measurements of hobs with carbide inserts using ultra-high accuracy coordinate measuring machines.


Hobs with carbide inserts, which are needed for the production of gears, have to be manufactured with high precision to achieve the best results in their application. The testing of these parts can now be completed easily – with the ‘Tangential Hob’ option of QUINDOS metrology software from Hexagon Manufacturing Intelligence. The parametrised software makes it very easy to generate the right programme for every single hob. The conventional manual testing time can be reduced to one tenth and the customer requirement for inspection reports can be fulfilled.

This software-option can be used for hobs with carbide inserts on every Hexagon ultra-high accuracy CMM. The only prerequisites are a star probe with six to eight styli and a mounting attachment, such as a chuck, to fix the hob. Measurements of modules 4.5 to 50 are possible. The software is very flexible because hobs with different qualities,
blade types (like main cutting edges or minor cutting edges in any order), number of threads and pitch directions, can be measured.


The short way to a documented hob test

The process is very simple. First the hob needs to be fixed vertically on the machine. The next step is the input of the parameters. The user is guided through the programme and is required to fill in some data about the hob. Afterwards the hob needs to be aligned by manual probing of five points. The next step is automatic measurement with 17 different measuring tasks. No rotary table is required for the procedure. In the end, the user gets the measuring results in an inspection report.

One software – for hob producers and gear manufacturers

There are two applications. On the one hand it is possible to measure newly built hobs. The results show if the base body and the finished product complies with the quality requirements. On the other hand, hobs with new carbide inserts can be measured. Therefore, it is possible to find incorrectly assembled inserts and to refit them before the hob goes back to the production of gears. That makes the software attractive for both hob producers and gear manufacturers.

The advantages are very clear. Because of the parametrisation, the software is suitable for all types of hobs and because the software works with DIN 3968, the inspection protocols are complying with the standard. By developing the software in partnership with specialist cutting tool manufacturer Ingersoll Werkzeuge, Hexagon was able to utilise front-line insight to refine the software functionality to meet the exacting standards needs of hob and gear professionals. “Hexagon offered us a solution which combines easy programming, high precision and dynamics,” comments Ingersoll’s QM Product and Production Optimisation specialist, Jens Lange.