The grinder tool posts are used to hold the high-speed grinder on your lathe for polishing, or fine grinding jobs. The grinder tool post holds the grinder body on center with your lathe. You can also use the riser grinder tool post when the lathe riser blocks are in place. The diameter of the center hole of the holder is .615".
(Image shows the grinder tool post in place holding the 8900 High-Speed Engraving Spindle, P/N 8900 sold separately)
About the High-Speed Engraving 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 P/N 4335 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 8900 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 overtighten this or the holddown 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 P/N 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.