Grinding_Fixture

I found that a special tool holder for grinding various tool bits would be a welcome addition to the Cuttermaster Tool & Cutter Grinder. I had tried using square 5C collets in the air spindle, but flexibility was severely limited. This attachment makes those tasks routine. It provides two axis' of rotation, and a third is accomplished by tilting the grinder head. The fixture is made of tool steel, and is very accurate. The round tool holder and base are 2.5" in diameter. Both are graduated in 1 degree increments, with the 5 degree mark 2X as long as 1 degree, and the 10 degree mark 2x as long as the 5 degree. The one degree marks are quite close, but easily distinguishable when using a magnifying visor (which I need for any close-up work anyway) Click on the link to the CNC page to see the engraving process. The next page shows another attachment that holds a 20ER collet holder. which I had scored at a long ago auction.

The basic parts are shown on the left, a bottom plate, the rotating disk that holds a vertical element, (the piece with the "U" milled on one end), the tool holder (not engraved yet), and a shoulder screw that fastens the rotating base to the bottom plate. It was necessary to mill the "U" in the vertical piece so an Allen wrench could be inserted to tighten the shoulder screw.

A close-up of the square tool holder is on the right.

Here is the bottom plate with two hardened guides attached. The guides slip into the T-slot on the tool grinder table. The rotating disk is fastened to the vertical piece with counter-sunk screws. The 1/4-20 shoulder screw is shown protruding from the base plate. The toolholder is attached on the top, with another 1/4-20 shoulder screw, and is positioned so the tool blank will line up with the center axis of the grinding wheel.

Two small brass plates are fastened to the bottom plate, and the top edge of the vertical piece. Each has a line scribed into it, and they are located at the zero degree position.

The bottom disk rotates to the desired setting, and is secured using the Allen wrench. The tool holder works in the same fashion.