We’re investigating the viability of replacing our legacy 2012 control circuitry of an NdYAG GoldenLaser with a Ruida controller / lightburn.
The legacy components are
- a pc that uploads via usb to the motion controller,
- controller moves machine and has a binary ‘fire’ pin output that goes to the first of two 4ru power control boxes, or high voltage units (hvu).
- hvu1 contains a controller board that has 2 db outputs that connect to a power control user interface (pcui).
- the pcui lets you set preburn, voltage, frequency, pulse.
- On the db pins, preburn is binary, voltage is a pwm signal, frequency/pulse is a pwm signal.
- When the motion controller fires the laser, this passes through hvu1, to pcui which activates the frequency/pulse signal.
- this essentially direct drives hvu1 which drives hvu2 and energises the laser pump, which is 2 xenon bulbs and a NdYAG crystal.
- hvu1 provides a pwm signal back to indicate voltage of the system, you can see it ramp up as the capacitors charge. However, pcui does nothing with this line, just hits a test point.
The pcui receives 8 or so binary error state inputs and a few other not super important signals.
This system we want to retire, keeping only hvu1/2. We can replace pcui with a microcontroller of whatever interface if needbe, although it would be good if a ruida controller can emulate these signals without having a separate item to maintain.
Reading about, it seems that the RF-Laser mode of ruida/rfworks and lightburn supports the concept of ‘preignition’ or ‘tickle current’, ie what our system calls ‘preburn’. It also seems to support a pwm signal output that… might be able to be controlled re frequency/duty cycle? So there seems some scope perhaps that a ruida controller could produce a compatible signal for the frequency/pulse signal. Some controllers seem to have 2 laser controls, ie 2 pwm signals that perhaps we could repurpose to behave as voltage and freq/pulse lines.
My question is twofold:
- Is there an ideal ruida model for this type of conversion? Ideally one where the screen unit and control unit are split.
- Can lightburn support this type of laser, by marking it as an RF Laser.
- How would that be configured?
- Can it support lead ins, and burn through holds?
Ideally we would end up with a system where lightburn can fairly directly control the power output of the laser, but if we end up with a system where lightburn is more binary and a separate system lets us control power, thats fine too, just less ideal. We could also potentially see a system where we have a custom uc that takes the ruida/lb signal and translates it appropriately. (This will probably happen in some sense to translate the various error mode codes)
We would like to stay with ruida and lightburn because our co2 lasers work on these, the experience is great and it reduces training for the ndyag.
As to pre-empt the questions of why, the current system is rough. The software requires vm emulation and lots of very touchy hardware dongle license trickery, and is very buggy and not great to use. The pcui unit is notorious for failing according to manufacturer, we’ve revived it and the controller inside hvu1 already (very sensitive to 3 phase mismatch, and the design isnt great in spots, ie error lines throw too much voltage and can burn out the board if you leave it sit in error state). If we just keep the hvus, replace the byzantine relay logic for interlocking on chillers etc, and put in a simple little uc to do a bit of translation we could hopefully ditch all the old crufty stuff. hopefully. At some point we anticipate it will die fully and want to transition before then.
We also plan to swap the capacitance based autofocus system in the machine currently with the ruida system, which looks like a pretty straightforward drop in replacement.
