The Toodle™ driving element is either hydraulic (in the case of Toodle Blue™) or pneumatic (in the case of Toodle Green™). In either device, jets are located in front of the turbine in order to convert the potential energy (pressure) to kinetic energy. The jets increase the speed of the hydraulic fluid (Toodle Blue™) or the air (Toodle Green™) and reduce the pressure in accordance with the Bernoulli formula.
The turbine converts the coolant, oil, or air linear velocity to rotating velocity of the main shaft. The turbine uses all available power for rotation in order to overcome friction in the bearings and viscosity friction between the turbine and house. Theoretically, one jet or several jets will deliver the same final no-load rotation speed. Yet multiple jet arrangements increase output power and torque.
Raw materials (metals) aren’t fully homogeneous. Thus, during metal cutting applications, the cutting edge faces different cutting forces due to material internal structure, CAM program and machine issues (stiffness, linear bearings preload, etc.). In the case of a relatively high torque spindle operating low power operations, these small forces variations can be neglected as they will not affect cutting force amplitude measurement. Moreover, when using an optimized size spindle (like the Toodle™) one may measure small forces amplitude variation.
The biggest disadvantage of a large size spindle is its relatively high dynamic runout due to residual unbalance internal forces. In contrast, the Toodle™ has an extremely low rotating mass, therefore it’s residual unbalance forces are also extremely small. The dynamic runout due to unbalance has a bigger influence on the surface quality and tool life compared to residual available torque. Therefore, the Toodle™ will have better overall results than other, larger spindles.
According to many field tests, using the Toodle™ for finish applications results in increased tool life and improved surface quality. And variations in cutting forces amplitude has almost no influence upon that.
SFI Technical Team