An article in the Italian magazine for Transmission Equipment (Organi di Trasmissione - Edition 07-2020) tells about the Precision and Flexibility of the Model TTB Evolution.
Free short summary of the article:
Tools for gear production
Swiss precision
With today's powerful tool grinding machines, it is possible to program and manufacture complex tools quickly and easily. But when it comes to the manufacture of tools for micro gears, these machines have clear limits due to their thermal stability. The Swiss company TTB Engineering has significantly overcome this well-known limitation of tool grinding.
If you consider a hob with a diameter of 6 mm and a modulus of 0.03, you first think of a turned part with a somewhat rough surface. The individual teeth (tooth height smaller than 0.1mm) with the necessary logarithmic relief and the foot radius of a few micrometers can only be recognized with a corresponding magnification.
These tools are required to manufacture extremely small, high-precision gears for robots, harmonic drives, watches, drones, etc.
Hobs are manufactured with specially profiled grinding wheels. However, this procedure has limits. It is almost impossible to insert the counter profile of a hob in grinding wheels for modules smaller than 0.3. Below this module range, there is only the possibility to path-grinding the individual tooth. However, this process is very time-consuming and, depending on the geometry, can take between 3 and 10 hours of continuous processing. However, the thermal stability of the tool grinding machine plays an extremely important role here. It is not possible to intervene in the grinding process during processing. The tolerances for these tools are a maximum of 3 µm in profile accuracy, flute pitch, thread pitch, etc.
This is where the extreme temperature stability of the TTB machine comes into play. Due to the unique machine structure, this requirement of maintaining dimensional stability for many hours can be easily met.
This process was further developed in the past years in order to also produce shaper cutters and power skiving in the module range from 0.05 to 0.3. Here, the program is generated with an in-house developed software so that the profile is maintained for a certain depth even when regrinding.
Thanks to specially designed clamping components, both shaft and bore tools from this product group can be accommodated into the machine. The automatic loading system can even be integrated into the process for larger quantities.