When attempting to cut a design and then run a laser toolpath to trace the toolpath of the cut design, it is important to get the starting points (zero points) of both toolpaths to align with one another. As long as the zero points line up with each other, it is possible to cut a design and then go back over and trace that design with a laser.
** In the examples shown below, a 90-degree V-bit was used to cut 0.125" (1/8") into the material and a 7-watt laser was used to go back over the toolpath that was cut.
When setting up this file, the 90-degree V-bit was zeroed in the bottom left corner of the material and zeroed to the surface of the material.
** To use the pendant to zero the bit to the surface of the material (after zeroing your X and Y-axes).
1. Slowly lower the bit to the surface of the material until the tip of the bit touches the surface of the material.
2. Zero the Z-axis by tapping the 'Zero-Z' button. Your Z-axis should now read 0.000 - just like the X and Y-axes.
This was demonstrated by creating a small dimple (circled in green in the illustration below) on the material surface, which will become more important later in this process.
After the dimple was created with the tip of the bit and the bit was zeroed to the surface of the material, the file was run.
Once the file finished and the bit returned home (to the zero position/starting point), the Z-axis was raised a few inches above the surface of the material so the 90-degree V-bit could be extracted and the 7-watt laser head could be installed.
*** IMPORTANT NOTE: power off/unplug the router or spindle before moving on to the next steps.
Once the 7-watt laser head was installed into the collet and the collet nut was snugged down to keep the laser head from dropping back out, the 7-watt laser head was SLOWLY lowered to the surface of the material (using the pendant) and then zeroed at the surface of the material. Then the laser head was raised to 0.100" above the surface of the material and then zeroed one last time.
**To set the laser head to 0.100" above the surface of the material.
1. Tap the box above the 'Up Z+' button that currently reads 0.000.
2. On the next screen (shown below), type in 0.100, then tap the red 'MOVE' button, to move the bit up to 0.100" above the surface of the material.
3. To exit this screen, tap the 'X' in the upper right-hand corner of the screen to take you back out to the main jog screen.
4. Now zero the 'Z-axis' one last time with the laser head 0.100" above the surface of the material.
5. Your laser head should now be zeroed and set to the proper height.
In an effort to keep the laser head as motionless as possible, it is suggested to take the cable that comes off the side of the laser head itself and run it up the side of the spindle/router (the router/spindle should be cool enough that it would not cause any issue running the cable up alongside it) and secure the cable in place using zip-ties or something like that.
*** DO NOT pull the cable more than what is necessary to run it up alongside the spindle/router. This can cause damage to the cable when it enters the housing of the laser head.
Since the X and Y-axes were not moved (only the Z-axis was moved straight up to remove the bit and attach the laser head), and the laser head is now set at 0.100" above the surface of the material, the diode of the laser head should be located pretty close to the dimple that was made earlier by the 90-degree V-bit.
6. Using the pendant, run a laser test by going to Apps > Laser > Press To Open > Test Laser. The laser will produce 3 quick pulses of light, creating a burn dot. (this process can be repeated a couple of times to make the burn dot a little darker and easier to see).
7. Once the laser test file has been run, raise the Z-axis a couple of inches to see the burn dot left behind, and then, using the pendant on SLOW, slightly move the laser head in the X and/or Y-axis to position the diode directly in line with the dimple in the surface of the material.
** Example: in the pic below, the red arrows indicate test burns and repositioning until the laser diode is directly in line with the dimple circled in green.
8. Once the laser diode is directly in line with the dimple, re-zero the X and Y-Axis and then the laser file can be run and should trace the image that has already been cut.
When the two zero points are aligned properly the laser file should burn directly over the file that was cut, like what is shown in the example below.
The (2) separate .tap files for this project can be found below.