Root Form Broaches

Root Form Broaches Root form (fir tree) broaches are used to generate female root forms in rotor discs which accept turbine blades. This process is for gullet grinding only and grinds both the right and left hand side of the cutter.

Process

Root form broaches are mounted in the fixture against the fence of a magnetic chuck.
Rake and shear angles are set with the B and C axes, respectively.
The base of the gullet is set horizontal using the A axis.
The contact probe locates the broach and the first tooth (or all teeth, if necessary).
The depth (or length) of the grind is set in the broach datafile, or the gullet depths can be probed as an option.
Multiple roughing passes can be assigned.
Hardened tool steel.

Machine Features and Benefits

Available on the Huffman HS-150, HS-190 and HS-200 series grinding systems.
A CNC A axis with cradle assembly is available as an option.
The B and C axes are available as either manual or CNC axes.
Broach fixturing is optional.
Features integrated probing.
Inch or metric input is possible.
A single CBN plated grinding wheel is required.
Probing routines (for given broaches) can be archived for future use.
Probing can be set to check the location of the first tooth only; using data file information for the location of all others, or it can be set to check all teeth.
Optional software is available to allow one wheel profile to produce a variety of tooth profiles.
Grinding from a hardened solid blank replaces the old method of pre- milling, heat-treating and then sharpening for dramatically increased broach throughput.