We have finally gotten ours to work, and it seems to be fairly reliable. We probably have about 20 hours worth of cutting on it with no problems.
Beeping
We never tried to fix the beeping. Instead, I wired in a switch that allows me to physically cut power between the laser power supply and the downstream side of the SSR that the original e-stop is connected to. What we've been doing is making sure to turn the laser power supply off whenever the door is open. This basically acts as another layer of safety. The only downside to this that I've found is that the power supply takes maybe 15 seconds to fully boot. If someone tries to start a cut before the power supply is booted, the beginning of the job won't have the laser firing. Pretty easy to get used to.
Wiring
We wired as discussed earlier in this thread. TH is tied to 5V, TL is left open, and IN is connected to the PWM output of the Atmel. Just like mentioned earlier in this thread, we were having problems with the laser not firing if the PWM value was below about 15% duty cycle. So we created a fork of the main LasaurApp repo where we modified the PWM output code to set (1% power level = 15% duty cycle). We also made sure that accelerations and decelerations were not setting PWM below 15%. At 0% power, we use 0% duty cycle. This has worked just fine so far. It is difficult to tell how the 15% constant on power compares to the pulsed laser that the original design is using. My suspicion is that our achievable minimum power is quite a bit higher than the minimum powers that the original design obtains. This hasn't been much of an issue for us so far. The fork is here: https://github.com/NU-MSR/LasaurApp Check the commit comments for more descriptions of the changes we made.
Weird Issue
The only strange behavior that we've encountered occurred after we did our initial tests. We started getting "Short Circuit Fault Analysis: The high voltage wire connected to ground wire or connected to the machine!" warnings whenever we set our power to 100%. Quite a lot of testing revealed that the current that was being drawn at full power was significantly above the recommended 26-28mA (even though we had already set the limiting potentiometer). We re-tuned this pot, and haven't had a problem since. Not sure what caused this issue, which is frustrating. However, our system seems fairly stable.
We have finally gotten ours to work, and it seems to be fairly reliable. We probably have about 20 hours worth of cutting on it with no problems.
Beeping
We never tried to fix the beeping. Instead, I wired in a switch that allows me to physically cut power between the laser power supply and the downstream side of the SSR that the original e-stop is connected to. What we've been doing is making sure to turn the laser power supply off whenever the door is open. This basically acts as another layer of safety. The only downside to this that I've found is that the power supply takes maybe 15 seconds to fully boot. If someone tries to start a cut before the power supply is booted, the beginning of the job won't have the laser firing. Pretty easy to get used to.
Wiring
We wired as discussed earlier in this thread. TH is tied to 5V, TL is left open, and IN is connected to the PWM output of the Atmel. Just like mentioned earlier in this thread, we were having problems with the laser not firing if the PWM value was below about 15% duty cycle. So we created a fork of the main LasaurApp repo where we modified the PWM output code to set (1% power level = 15% duty cycle). We also made sure that accelerations and decelerations were not setting PWM below 15%. At 0% power, we use 0% duty cycle. This has worked just fine so far. It is difficult to tell how the 15% constant on power compares to the pulsed laser that the original design is using. My suspicion is that our achievable minimum power is quite a bit higher than the minimum powers that the original design obtains. This hasn't been much of an issue for us so far. The fork is here: https://github.com/NU-MSR/LasaurApp Check the commit comments for more descriptions of the changes we made.
Weird Issue
The only strange behavior that we've encountered occurred after we did our initial tests. We started getting "Short Circuit Fault Analysis: The high voltage wire connected to ground wire or connected to the machine!" warnings whenever we set our power to 100%. Quite a lot of testing revealed that the current that was being drawn at full power was significantly above the recommended 26-28mA (even though we had already set the limiting potentiometer). We re-tuned this pot, and haven't had a problem since. Not sure what caused this issue, which is frustrating. However, our system seems fairly stable.