About the Call
On May 8, 2022 I had a service call from Trotec’s service technician Roy K. I’ve had the Rayjet50 for 2 years and although it has had only a few hours use, it seemed appropriate that since he was in the area, I’d get him to give it the once over. Given its infrequent use, I was not expecting any issues and almost didn’t bother. But, I figured I’d learn a few things. It turned out that it did need adjustments. Before I cover them, I thought I’d describe how the machine functions — set the stage as it were.
Note that the terminology I use to label and describe the parts are not taken from documentation and may be completely different from official labels.
In all, it was an excellent experience. Roy was knowledgeable and helpful and I did learn a few things.
How the Rayjet50 Works
This is abbreviated description, mainly to set the stage for describing the maintenance adjustments Roy made.
The image below shows the concentric beam paths for the Diode Laser (used to locate the work) and the CO2 Laser (used to cut/engrave the work). Unlike many lasers in this size, the CO2 laser tube is ceramic, rather than glass. This allows the tube to be air cooled rather than water cooled. As a result, a water tank. water chiller, and water pump are not necessary. That saves significant maintenance time and effort, and is more reliable. The down side is significant fan noise. It is orders of magnitude louder that one would tolerate on a computer, for example.
The Laser Mechanism
As you can see, the diode laser is directly above the combiner, and is reflected off the surface and on to mirror 2. The CO2 laser is reflected off mirror 1 and comes into the back of the combiner and goes straight through to mirror 2. The combiner is essentially reflective for the diode laser and transparent for the CO2 laser. The two beams are concentric, meaning they have the same path. The CO2 laser should fire exactly where you see the red diode laser. Both beams take the same path from mirror 2 to mirror 3 and through the focusing lens.
Note that the X-axis is left-to-right, the y-axis is front to back, and the Z-axis is up and down.
Mirror 3 and the lens are in a fixed group and travel left-right on the X-axis.
The X-axis Mechanism
Mirror 3 and the lens are in a fixed group and travel left-right on the X-axis.
The Y-axis Mechanism
The mirror 3 / lens group and mirror 2 are in another group and travel front-back on the Y-axis. They live on the X-axis track, which moves front-to-back along the Y-axis.
The image above shows the cover open on the track. The image below shows the cover closed.
The Z-axis Mechanism
The platen (work holding surface) travels up-down on the Z-axis. This view is from the right side. It is mirrored on the left side. There is a lead screw on each corner. The platen supports are heavy bars left-to-right across the front and back that support the platen. The drive belts rotate all four lead screws simultaneously. The platen nut locks prevent the platen nuts from rotating with the lead screws. This moves the platen up and down, lifting and lowering the workpiece.
Rayjet50 Service Adjustments
Platen Leveling
The platen was found to be about 2.5mm lower on the front right corner relative to the other three corners. The measurement was taken using a digital caliper measuring from the underside of the X-axis track to the top of the platen. The X-axis track was moved to the back and a measurement taken at each end, left and right. Then it was moved to the front and the measurements repeated.
Adjustment was made by releasing the platen nut lock on the right front lead screw (the one labeled in the picture above) and manually turning the platen nut until that corner was within tolerance relative to the other corners. Then the platen nut lock was put back in place and locked.
Laser Alignment Test
Three laser alignment operations were done. Adjustments 1 and 2 were done by adjusting mirrors 2 and 3. Adjustment 3 was done by using Rayjet Manager to jog the lens to the correct position and resetting the 0,0 setting to that location.
- Alignment of the CO2 laser.
- Alignment of the red diode laser with the CO2 laser. It was initially off by about a millimeter.
- Location of 0,0 position in the top left corner. It was moved to coincide with the back left corner of the hexagon platen insert
Laser Power Test
A portable laser power meter was used to measure the power output of the CO2 laser. The results were inconclusive, so a cut test was conducted on plywood and the results were as expected.
Results
The laser is now in focus on all 4 corners of the platen, the red dot laser is concentric with the CO2 laser, and drawings can be referenced to the rear-left of the platen without having to move the laser manually to that position. All-in-all, a good day.