Don’t doubt that… I just wonder how many end up with grade B tubes when they replace them…
Not to forget that we have witnessed many K40 users:
- Running without coolant and/or poor flow with no water monitoring.
- No interlocks on coolant temperature
- Using digital panels that mislead about real power levels
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Totally agree. My stock K40 tube lasted me about 3 years running not more than 16mA on the tube. But I had a fair number of hours on mine since I was running a small side business. Replaced it with a quality SPT tube and it was clearly better then my stock tube when it was new.
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M2 nano ha driver A4988 e non è compatibile con lightburn
M3 nano ha driver silenziosi ma è uguale alla M2 nano,
compra scheda mks DLC 32 ,costa poco ed è compatibile con lightburn
Do you suggest they run 80% power all the time? Is that just a conservative value or?
If I’m reading you right, set the pot, to 80% of it’s 100% capability?
So this would relate to 100% power in the layer or 80% tube current?
I’m just repeating what’s been stated hundreds of times for the K40 OEM tube/LPS setup and that is to NOT drive the tube at full power, get a current meter on the return line of the tube before even using the machine, set the max current to 18mA or less using the POT or the digital display(while reading the milli amp meter).
After that, you can set your firmware so that it puts out max PWM and it’s equal to 100% and then you can set your power levels in Lightburn to anything from ~5 or 10% to 100% and it won’t inflict any unusual wearing of the tube.
If you get a “good” tube then it’s a completely different story. You can set your POT or digital display for what ever current the tube manufacturer spec’s as the max current and nothing changes in the firmware or Lightburn. Well, except you’ll likely have to lower your power levels or greatly speed up the speeds because a “good” tube will have more power than the OEM tube.
If Scorch could figure out the M3 Nano’s PWM functionality from the same no amount of information that would be useful. But, currently there’s only MeerK40ts functionality of emulator power modulation for the M2/M3.
MeerK40t currently has a lot of functionality on par with lightburn, it also has a user experience on par with middling software from the early 2010s. If you merely want features, I can strongly suggest that MeerK40t has those covered. It has so many features that we spend considerable time and energy hiding features.
One of the features inside meerk40t is the ability to emulate a Ruida DSP sitting on the network. This actually makes it so that lightburn could run the regular M2 hardware. It’s just a language to be emulated. The same is being done for GRBL too.
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What I was trying to get across, is that the current control on the lps is the pot.
If you set the pot for 80% and the power (pwm) to 50% it will run 80% power 50% of the time…
The only current control on the lps is the IN terminal…
All the pwm does on these is turn the tube on and off, it is not controlling the current…
That’s my only argument… 80% is probably safer…
And I was trying to say that you don’t want to over drive the tube and the other “power” settings and controls are to control what kind of power is put on the work piece. If 80% is the 18mA setting it doesn’t matter if it’s 80% for 50% of the pixel or if it’s 50% power for 100% of the pixel it’s the same amount of energy on the target material.
But who knows, not many run a Ruida on a K40 so all we know is what’s been on the market for the past 10 or so years. I still think if it can be shown that how Ruida does it is superb, the open source firmware devs would change to that method. Current 32bit boards should be up to the task.
It can and usually does make a difference if you dump 100% power for half the time rather than a continuous 50% power… although our meters will read the same…
Someone was cutting stencils with a K40, the cut line had a lip on it from the laser. I suggested he set it for 100% power and the pot to ~5mA… he got the cut dialed in using that procedure…
The Ruida, I would be hard pressed to put a controller into a machine that cost nearly as much as the machine itself, so I completely understand a lower cost option.
Surprisingly I have seen a couple of K40 with Ruida controllers… one with a 70W tube shoehorned into that tiny case. It’s amazing what people do with these things.
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Enjoying reading the debate and I have learned a lot so far so summarising:
Cutting:
I think we are agreeing that without any specified maximum current rating on my fairly new Cloudray tube, the maximum current can be 18mA so as not to overdrive it. I am currently setting the maximum at 3.8v (15mA) on my voltmeter but I will re-run my cutting tests as that additional 3mA might make the difference in some cases (thick MDF and Acrylic) between 1 pass or 2.
- On my current tube 15mA represents 3.8v and 18mA is now 4.4v.
- As it stands cutting works for me using Inkscape to design 3D models, Living Hinge designs, jigsaws etc with K40 Whisperer to control the machine which tends to be full power (currently 15mA) unless I am cutting 2mm MDF which only needs 10mA, one pass. For bog standard 3mm ply I get from my local hardware shop, (I used to buy ready-made birch ply mats to engrave on), they cut large sheets into 300x200mm for me so I can cut 6 x 90x90mm coasters from a single sheet in one pass so each cost very little and my DIY chiller keeps within temperature (18 – 20C) for up to 1 hour.
Engraving:
This was the reason for my original post. I can engrave on organic materials and glass, but tile is the problem and it is hard to create an engraving matrix without being able to control the power to determine the best settings. I have created a 10x10 greyscale matrix in Inkscape but I have to sit with it and increase the power for each horizontal line which is irksome and is something that was automatic before on LaserGRBL using the append feature which essentially strings together different routines which can have different power levels hence anticipating having to move to Lightburn to achieve this.
So, my remaining questions are these which relate to getting the best experience for engraving on tile and it looks likely I may not need Lightburn in order to achieve this:
This may give me the functionality I am looking for so this is a good start. I have downloaded it and will check it out in the next few days but can I set it up to lase an image well on tile?
@jkwilborn Your tile looks great. Although I appreciate you are not using a K40 so your setting will be different from what I will need, yours might give me a clue as how to get there:
- What coating on white tile did you use and how did you apply it?
- Can I achieve this resolution using a stock head or do I need a compound lens?
- Do you pre-process the image and to what resolution and DPI and then passthrough or can I process the image on MeerKat and if so what settings?
- What dither pattern or settings did you use? I found Floyd Steinberg worked best on LaserGRBL with a diode laser.
- What speed and power settings did you use?
- What air assist power?
- Answers to any other questions I should have asked.
Many thanks in advance
Just TiO2 and water with an air brush. It took multiple coats, but it dries real fast while you are standing there. Too much and it just pools the water. I put a bit of food coloring in it so I can see where it’s going on the white tile.
Also have had pretty good success with the TiO2 + water + white acrylic paint. Isn’t as messy, dust wise. With only water, you can wipe it off easily and leave fingerprints…
I did this with a 2" lens. Some simple cropping with gimp, but it’s really done with Lightburn.
Most of the other questions are here on the actual layer.
I have the low pressure air anytime the machine is in run mode. I run enough to keep the lens clean. Too much air will remove the TiO2 powder.
- A China Blue 40W – 2" lens configured for engraving.
It’s a bit less than 5W out… I do have a 60W lps, so it’s got a quicker response time than most.
I have never used Meerkat, so I can’t help you there.
Did I miss anything?
Good luck
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Many thanks. You do use Lightburn so I will get the trial version using MeerK40T and see how it goes and let you know.
I’ve never had a K40 and I know the stock control board isn’t compatible with Lightburn…
Lightburn is gcode/dsp/galvo support but only with specific controllers.
I only run Linux, so the software I use has to support the Linux os.
@mcdanlj has made a comment on using Lightburn in association with Meerkat somehow… as a dsp? Don’t follow … yet.
Meerk40t has the ability to speak the same network protocol as Ruida, so that Lightburn can talk to a K40 with an M2 or M3 Nano through Meerk40t translating from the Ruida protocol. (@Tatarize is there a link to documentation on how to set that up? I didn’t see it when I glanced at the wiki.)
That doesn’t make it a DSP. It does have a way of modulating power (the PPI thing I linked to earlier) that as far as I know K40 Whisperer doesn’t have implemented. It doesn’t mean that it’s a 1-1 replacement for a Ruida controller; only that it’s a next step for experimentation that won’t add cost. 
Absolutely, as you said in the original response its worth a punt and it will give me a chance to check out Lightburn without the need, initially at least, to get a new motherboard. Yes I am a bit surprised this hasn’t been implemented in K40 Whisperer. It’ll be a week or so before I get onto it but I’ll let you know how I get on.
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It speaks UDP.
It’s a messaging protocol with no error control, doesn’t care who sends or sent it and can’t rearrange the packets if they don’t arrive in the proper order…
I can connect two pc’s to my Ruida, simultaneously, and it can’t differentiate between them…
I’d like to know how this Lightburn → Meerkat works, it might be very helpful to others… 
I know that the protocol is carried over UDP. UDP is a low-level protocol implemented on top of the IP datagram protocol. TCP is the most common stream-oriented protocol implemented on top of the IP datagram protocol. Many application-layer protocols run on TCP. HTTP is only one of them; there are many more. Similarly, many application-layer protocols run on top of UDP. Some of those protocols deal with dropped packets gracefully by implementing retry at the application layer. Others don’t. The application layer protocol used by Ruida is only one of the many application layer protocols implemented on top of UDP. The protocol that Meerk40t is implementing is the application layer protocol implemented by Ruida controllers.
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I did this very thing in 2019. You can see my adventures here:
http://www.beevo.org/LaserEngraver/K40_Laser.html
I will gladly answer any questions you might have on my conversion. It has been rock solid since the build and gets worked pretty hard at times.
Beevo
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That’s a very nice job… 