Sherline 3074 Drill Chuck Tool Holder
Many jobs on a mill require a change of tools from one size to another or from an end mill to a drill bit. If the depth of the hole is critical, putting a drill chuck into the spindle taper each time and pulling it up with the drawbolt is time consuming, and tapping the drawbolt to remove it from the taper can cause the column alignment to be compromised if the column is not properly supported while it is removed.
This new holder makes it possible to screw drill chucks onto the spindle just like end mill holders are attached. An additional advantage is that the tool length remains the same each time, so no changes are needed in the Tools Table if you are working with a CNC machine. The drill chuck is simply threaded onto the 3/8-24 thread of the holder, the drill bit is mounted and the length measured.
Now, each time it is threaded onto the 3/4-16 spindle thread it returns to exactly the same place and is easily removed with a Tommy bar. Having a drill chuck and holder for each different drill size in your operation can save a lot of time during tool changes. A Tommy bar is included for tightening/loosening the holder on the spindle.
NOTE: The holder does not include a chuck. If you do not already have a 1/4″ or 3/8″ Jacobs drill chuck, you can order them as P/N 3072 for the 1/4″ chuck or P/N 3073 for the 3/8″ chuck. The #1 Morse arbor is removed from the chuck and the 3074 adapter is screwed on.