Tool Setter
The tool setter is a fixed reference surface that MASSO uses to measure tool length. With Auto Tool Zero, MASSO measures each tool on the tool setter and automatically compensates for differences in tool length between tools. It works with both manual tool changes and automatic tool changers.
The thickness of the tool setter does not matter, as long as its height does not change. This is different from a probing touch plate, where the plate thickness must be known and compensated for.
Prerequisite: homing must be set up so the spindle can find the tool setter. See Homing Setup.
How the tool setter works
When MASSO is homed, the tool in the spindle is touched off on the tool setter. MASSO stores this length as the reference for all later tool changes. The value stays valid until it is remeasured or changed manually. The tool can then be zeroed to the surface of the material as required.
When MASSO performs a tool change with an M06 command, it measures the new tool, compares it to the reference tool and adjusts the tool height offset.
WARNING: The golden rule of the tool setter: after homing, do not change the tool in the spindle without using an M06 command. If the tool or its length changes without M06, re-home the machine. Otherwise every later tool height will be wrong, which can damage the machine or workpiece. This applies to both Auto Tool Zero and manually measured tool lengths.
Choosing a tool setter
A switch-based tool setter is recommended. It uses a mechanical contact, so it does not depend on the tool being grounded.
A touch-plate-style tool setter can also be used, but the plate and the cutter complete the circuit, so the spindle and tool must be reliably grounded.
WARNING: With a touch-plate-style tool setter, if the tool or spindle is not properly grounded, MASSO will not detect contact and the tool can crash into the tool setter. Check the grounding before every use, and test the input by touching the tool to the plate before running Auto Tool Zero.
Wiring a switch-based tool setter
INFORMATION: A tool setter with a normally closed (NC) contact is fail-safe and does not need an over-travel switch. If the circuit opens because of a fault or broken wire, MASSO detects it and prevents probing. A normally open (NO) contact is not recommended, because the normal and fault states look the same.
- Tool setters with a second switch for over-travel protection can be connected to Cycle Stop or wired into the E-Stop circuit. This stops the probing cycle if the primary switch fails.
- Some tool setters include active components such as LEDs or inductive sensors. Follow the manufacturer's wiring instructions.
- More wiring diagrams are available on the MASSO Forum.
Wiring a touch-plate-style tool setter
The plate and cutter complete the circuit when they make contact:
- A pull-up resistor of at least 1/8 W pulls the input High.
- The input must be inverted so it reads Low when the tool setter is not triggered.
- Do not leave out the resistor or the positive supply, or the tool setter will not work.
- Do not replace the resistor with a direct connection to the power supply. This causes a short circuit when the tool touches the plate.
To use one touch plate as both the tool setter and the probing plate, see Probing Touch Plate.
Assigning the tool setter input
- Go to the F1-Setup screen.
- Select the input the tool setter is wired to and double-click it.
- Select Tool Setter Input from the list and double-click to confirm.
CAUTION: The input must show Low when the tool setter is not triggered and High only when it is triggered.
INFORMATION: To invert an input, select it in the INPUTS list and press the spacebar. The setting is saved automatically. 
Manual tool change
During a manual tool change with Auto Tool Zero enabled, MASSO moves to the tool setter, measures the new tool, calculates the tool length offset and continues machining with the correct compensation. See Manual Tool Changer.
Video
This video shows how to set up a tool setter step by step.
Troubleshooting
Tool length incorrect after a tool change
The most common cause is changing the tool after homing without an M06 command. This changes the reference tool length, so all later tool measurements are wrong. Either change the tool before homing, or let MASSO change it with M06 during the program.
Tool change ignored in G-code
If the requested tool number is the same as the current tool shown on the F2 screen, MASSO does not perform a tool change. For manual tool changes, give each tool a unique tool number in your CAM software.
