A ruler guide for estimating tool length on a CT40 (or "CAT 40") CNC tool holder for use in a probing cycle program. This guide clips right onto a CT40 tool holder. It can be used while the tool is either on the bench or in the spindle (there should be enough room to clear spindle drive keys while installed).

Usage

1. Clip this guide onto a CT40 tool holder.
2. Push a ruler or scale up against the ledge that sticks out toward you.
3. Measure out where the tip of the tool ends.
4. Use the measurement in your probe cycle.