Cutting Timing Belt Gears

摘要

Now there is the question of setting up the grinding tool in the lathe. For this I made a simple gauge. Draw out the 20° angle on some thin card (photograph 21) and cut it out (photograph 22). Cut a piece of 2mm thick steel 25mm x 80mm and glue the card template to it (photograph 23). Line up in the milling machine and machine away the excess down to the line (photograph 24). I like to stamp any bits of tooling to make future identification easy. With the tool mounted in the lathe tool post it's an easy job to set the 20° angle required (photograph 25). The tool works well in practice. With the lathe running and the saddle locked the top slide is advanced until the slitting saw just touches the grinding wheel at which point the dial is zeroed.