Chinese Co2 laser Speed for cutting and engraving is very slow after changing the tube and power supply

[fmchaur (frederick chaur)]

Hello everyone, I am operating Chinese Co2 Laser Engraving ang cutting machine 100W, Board RDC 6442s-b (EC), software RDworks 8.01.31.
The first time i used the laser machine it is actually working fine,
Here is the parameter setting that i used

-after a few months the laser tube was damage even the laser tube power supply, we called a technician to solve the problem we encounter, the technician offered us to use 80w laser tube because that is the only available stock in their company he also change the power supply.
After the installation of the new laser tube and power supply. we tried to run the machine and here comes the problem, the connection from mainboard to the power supply is this:
mainbord - powersupply
Gnd - Gnd
Lon1 -TL
LPWM1 - In

-The problem in this connection is every time we turn on the machine, the laser will fire automatically as the head is moving but the ammeter is not showing the power output of the laser, we also change the position of the head after turning on the machine. Every time we move the head X and Y the laser will fire. I try to press the “PULSE” button of the control panel but there is no laser coming out. Also we tried to cut and engrave but then another problem occur the speed is very slow in cutting and engraving with the same setting or parameter that i used normally.
-The Technician also reset the parameter of the machine in the control panel.

-after the problem we encounter the technician change the wiring diagram from mainboard to power supply

This resolved the problem for auto firing every time we turn on and moving the head, the only problem left is the speed for cutting and engraving. i try to test the speed in the machine by pressing the “Frame” button in the control panel and it works fine. But if i will command to cut or engrave from the computer connected to ethernet or usb cable the speed is very slow.
the normal speed that i am using is from 1-100mm/s. Now i am using 500mm/s but the output speed is like 1mm/s even if i download to usb and then connect to the Udisk there is no difference. i tried also to cut or engrave w/o firing the laser but the same issue.Processing: laser on.mp4…

[Stroonzo (Jeff)]

@fmchaur

software RDworks 8.01.31

This is a LightBurn forum.

Your laser is not connected in the recommended manner that Ruida suggest for a glass tube. That is, you can / should use PIN 5 (the analog signal) for the laser power.

Safe Maximum PWM with CO2 Lasers

If you have a glass tube laser, you should just use the analog output of a controller for the power curve. Even if you had software or a controller that supported PPI (that’s fast switching of the laser on and off while cutting aka Pulses Per Inch), that is a hard On/Off 5v signaling to the PSU. This frequency setting you are referring to is something different and is designed not for glass tubes. It is for RF excited lasers (RF lasers). You should have it set to 20kHz and leave it. Otherwise…

Ruida 644XG red lights on and one blinking

You have either a limit switch (CN3-4,5)(CN4-2,3,4,5) door switch (CN2-3) or water protection (CN5-4) halting your machine. Also, the way your controller is wired for CN5 (Laser 1) is not how Ruida suggests for a glass tube. I am not saying it won’t work using PWM (CN5-3) to the Laser PSU (because I do not know). I’m only referencing the Ruida documentation and the way my machine is wired. Ruida suggests, for a glass tube, using L-AN1 for laser power control. [image]

You also need to check that your laser PSU is calibrated to the manufacturer’s electrical current (mA) specifications:

Could this be a sign of a bad laser tube?

I am beginning to think you need to tune your laser PSU (as if the PSU is set too low). To do this, you need to know the highest mA draw specification for the laser tube longevity. A guess for an 80w tube may be somewhere in the upper 26 - 28 mA range (but you need to check to be sure). With this number in mind and with a mA meter on the machine (if you don’t already have an ammeter installled on the machine, they’re a pretty easy retro fit down stream of the laser tube) you can properly tune…

@fmchaur

The Technician also reset the parameter of the machine

Sounds like the technician changed too many settings while experimenting with your machine. You will need to review all of the vendor settings and check these against your machine’s requirements.

[jkwilborn (Jack Wilborn)]

You would hope any technician would have made a backup of the original configuration.

I have the same document., it’s on page 19.

Before that on page 14 in the documentation is

The recommended drive on this graphic to the lps is from the LPWM1 output on CN5. Everyone I know uses the LPWM1, I thought, except you…lol That’s how mine was wired from the factory.

Page 21, dual CO2 laser, they use the PWM (1 & 2) for control.

To add to the confusion, as the picture shows, on my Ruida there is no L-AN1 or L-AN2 on CN5/CN6 or any other connector. Pin 5 is 24v. I guess this makes this hole discussion rather moot.

I’ve used the ‘period’ settings = 1 / frequency, commonly called the PWM ‘base’ frequency many times, It’s nice it’s adjustable.

The tube will lase when it’s ready or has enough energy to start lasing. It is at 100% when it lases or it isn’t lasing. Thinking along the lines, that using an analog signal would just slow down your power supplies response time. Slower rising edge… more time.

All of the graphs of power supply responses that I’ve seen use a digital transition for a trigger.

The power supplies have a response time, most are <= 1ms. From the link:

The faster the ‘period’ the less time the power supply has to respond and be within the PWM cycle. So there is an upper limit on how fast the PWM period is to the supplies response time for it to be usable. It is also where consumers of these get burnt. It’s difficult for most people to measure.

I don’t know anything about RDWorks, wonder how he got here???

[fmchaur (frederick chaur)]

Thank you, I appreciate all your suggestions.