The grinder tool posts are used to hold the high-speed grinder on your lathe for polishing, or fine grinding jobs. The riser grinder tool post when the lathe riser blocks are in place. You can also use the grinder tool post to hold the grinder body on center with your lathe.
Image shows the grinder tool post in place holding the High-Speed Air Grinder (sold separately.)
About the high speed air spindle…
In most machining conditions it is not necessary to achieve tool speeds faster than the 10,000 RPM that can be produced with the standard DC motor spindle with optional high-speed pulley set. However, for engraving and other applications where extremely small, pointed tools are used, higher speeds are required for good finishes and acceptable feed rates. The High-Speed Air Grinder spindle is capable of speeds up to 54,000 RPM and will hold 1/8″ diameter cutting tools in its collet spindle. Three carbide tools with various cutter face angles are provided with your engraving head along with 7 grinding tips.
The high-speed spindle fits into the hole in the toolpost and a screw is tightened laterally to secure it in place. Do not over tighten this or the hold-down screw that secures the toolpost to the table. The grinder can be used for putting a fine finish on hard parts, but it does not have the high torque needed to remove larger quantities of metal.
See more on the high-speed grinder for more details on its use.
A carbide tool is being rotated at extremely high speeds. Should it shatter, pieces are flung outward at high speed. While eye protection is always recommended for any machining operation, good eye protection is absolutely imperative when using high-speed tools like this.