Man we are having some weird problems with our laser cutter. It’s suddenly acting super weak, and can’t even get through 3mm acrylic after like 4 passes.
But it also appears that it’s somehow acting stronger at lower percentage power? We noticed this cuz the regular pulse wasn’t doing anything and then we drop the power of the pulse to like 20% and then it started burning our marking tape. I ran a test with light burn and found that between 25 to 45% power it seems to be running the strongest? Can we get like nothing below 10% or like above 80%. I can’t find anything out about this, anyone know what’s going on here?
It seems like it could be maybe the power supply? Or the tube? The tube color is pink like it’s always been. I don’t know if it is in the dreaded TEM01 mode or whatever, i feel like sometimes it fires a nice circle and other times 2 dots-ish. But it would still be confusing as to why it seems more powerful at 20% than 100%
More information:
I have aligned the crap out of the mirrors:/ I think there might be something wrong with the tube alignment? I shifted it a little bit and it seem to make everything worse, Even though the laser path seems to be hitting dead center for all the mirrors?
It’s never been the best laser, the people who sold it to us were kinda swindlers and never really set it up correctly, so ill admit this is not the BEST laser cutter, and they are all kinds of janky things about it , but it’s been a decent workhorse the past 3 years.
This picture below shows a set of pulses with the tape in front of a mirror, taking it 20%, 50%, 60% and 99%
The machine is a “corvus BCL 0605MU” but I haven’t seen this anywhere else on the internet. It seems to be like a generic CO2 laser cutter, Is this what they mean by a k40 laser cutter?
No, it’s definitely not A K40 is a toy compared to your 100Watt machine. However, I don’t know this brand either.
You probably have to start by getting the tube back into the correct position for the frame and M1. Then you have to test what comes out of the tube with a short, low energy pulse to judge it. What does your 99% equate to in mA?
Btw, 3 years of production - that’s a fine result for a laser as a production machine. If it turns out the tube is broken, you probably have to invest in a new tube including power supply.
I don’t know how many milliamps it puts out. On my display it’s always just said zero milliamps 0 volts (again I think because it was never set up correctly). Do you even know if there’s anything I can run wires between that will help the display know how many milliamps it uses? Here’s some pics of the inside
It’s been 3 years but mostly as a prototyping machine. Not a super serious production machine. So like we’ve used it a lot but not like churning out products with it.
You’re describing the typical failure mode … it’s difficult to keep it aligned and doesn’t perform well. Add to that it shows higher power at it’s low end.
A good tube should last about 10,000 hours, or about 5 years in commercial 8 hour a day production.
Most of these machines are low cost and you’re lucky to get a couple, three years of hobby use out of them.
The tape pictures looks like you are not in TEM0 resonance.
Make your pulses much shorter or less power. There should not be a hole, that tells us nothing.
I cut targets out of water coloring paper that fit into the mirror entry…
This was my previous tube when I caught it failing during an alignment.
It’s not burnt, but it’s not a round equally distributed power band across the mark.
This mark was dead center, so I think going out of resonance also moved the beam… I believe this is what causes difficulties in the alignment procedure.
As I read it, you have no ammeter installed on your machine. It is usually used as an indication of the “output level” of your laser. Without an ammeter, your power settings are a bit of a guess, if your power supply for the tube is not regulated to the maximum allowable value, you risk driving the tube beyond its limit. As far as I know, none of the payable Chinese machines are regulated. Either you adjust the power supply yourself or you stay below the recommended mA.
I would recommend that you retrofit a (mA) ammeter when you change your tube/power supply. It doesn’t cost much and with a little help from the forum you should be able to install it yourself.
Lasertube manufacturers have for all co2 tubes a recommendation of a given mA value for the respective tube. Together with a correctly regulated power supply, an ammeter should be standard on all co2 laser machines.
@jkwilborn knows quite a bit about this subject and can probably guide you to measure the given voltage by e.g. 50% of power setting.
I wanted to thank you all for the great feedback and tips! really helpful forum here, I really appreciate it!
I will run some more tests on it in a bit and show you my better burn patterns (not holes )
but from what you are all saying, im guessing the thing is probably due for replacing. Given the fact that it’s been cooled in the rainforest by a terrible CW-3000 for the past 3 years (that i have had to hack twice to get working), it’s probably time to do things correctly a bit!
So i will likely be trying to order a new tube. I have to order from the USA and get it sent to panama (where i live and have this jungle makerspace).
So i will likely try to get a
new laser tube
** The old “100W laser tube” it came with is only 70cm long (which from looking around, there are NO 100W lasers in tubes that short)
new power supply? - should i get this too?
CW-5000 (the actually cooling coolers, correct?)
if anyone has suggestions on good ones to buy, im all ears!
It looks like up to about an 80cm tube will fit fine inside my laser cutter, and from looking that seems to be about a 40-50 watt laser tube correct? I would like to get whatever is most powerful i can fit in there!
Is this your machine?
This one says 80Watt, do you have a hole in the side to get a longer tube mounted, just like in the picture?
70cm with Ø50 corresponds to 40 Watt, something or the other does not match the description you have, send further up in the mail. Is there another sticker on your tube with a Watt indication?
A real cooling machine is essential, the CW 5000 is fine.
Generally speaking the longer/larger diameter tube has more power. I believe most of it is length, but as they get more power, they get increase in diameter.
My China Blue was a 50W machine, but it only had a 880mm tube in it and it read 44W with a Mahoney meter…
I replaced mine with this one from Cloud Ray… I got the 45W model which is 850mm in length…
The way you cool your tube, is somewhat relative to the area you live. The 3000 is find if you live/work in an area that is sufficiently below the temperature you with the tube to operate. I live in the SW desert, so the 3000 was more of a heater…
Ahh that’s cool, yes that is EXACTLY my machine, except i have no hole in the side like that at all for a tube to stick out! This is just extra confirmation that the people who sold me my “100w” laser were boldly lying to my face!
Yes, it’s sad. But excuse me, you haven’t done your homework properly 3 years ago.
Let it be, life is too short to be angry.
For the future, you must find out whether you want to continue with a (new) 40 Watt tube or whether you have the option of putting a 50-75 Watt tube in your machine. If there is preparation to be able to expand, typically a blind plate in the side, then you only have to find a square extension box to bolt onto your machine as protection. I would probably make it myself in MDF or HDF. Then there is “only” to find out whether the new diameter can also be in your tube holders, the probability is high.
Look for a “package solution”, e.g. from cloudray:
Not sure if you’re looking for another hobby but 3D printing is very gratifying. Similar to laser cutting in that way. But fabrication using an additive process vs subtractive tickles a different part of the brain and suitable for different jobs. Costs have come down considerably while ease and quality have gone up. Competent printers can be had regularly for $200 USD while $300 gets you some additional conveniences. Newer high-end models are quite fast and impressive and there are all sorts of other models to fit every price, depending on your needs.
No, strangely I have been reasonable about a 3D printer. The technique interests me a lot, but if I’m completely honest, I’ve only needed 3D printed parts a few times and then wanted a printer.
It’s immediately different with a fiber laser…I’m really trying to convince myself that I don’t need such a machine…
I really want to test such a machine, it is the learning process itself that catches me the most.
But the idiotic war and the resulting economic crisis have had a relatively large impact on my financial situation. At the moment, I am keeping an interested eye on @jkwilborn and am happy about the progress he reports on his new machine.
it says the “max working current” is 20mA. Does this mean that this is a good current to cut stuff in general? Like a majority of the time should i set up my system so max power is around 19-20mA? or is it like that’s the max power that i should always make sure to stay way under?
right now i don’t go above 15mA, but im not sure what kind of mA setting i should aim for to have the machine running at in general?
other notes:
it all seemed to be packed quite well and everything came in good working order!
there was one glitch where the high voltage line seemed to have had a knick in it or something because when i did some initial pulses, the electricity arced and actually made a hole in the wire! I of course stopped everything, and then insulated up that section a bunch, now the whole system seems to work fine!
here’s a picture i took after it arc-ed. I have been wondering whether i should leave it insulated as is (and everything seems to be functioning) or if i should cut out this section of the wire and twist the new ends together and insulate them.
It doesn’t look good, luckily nothing bad happened.
I want to strip a piece of approx. 10 mm and see how the cable is doing. The best thing would be to install a high-voltage connector, it is the red connectors that are used in advance. If this is not possible, a sleeve must be made, a pipe stump which is 60mm long and has approx. the triple diameter as the cable. The sleeve must be filled with silicone and it must be ensured that the cable is in the middle of the pipe and does not touch the outer wall.
I have also used a shrink sleeve with mastic on the inside, it is intended for high voltage. Everything else will not do, in my opinion. The high voltage will find a way out through false insulation.
Regarding your mA settings, I have done tests with 5% power increase and 1 sec. pulse. At about. At 70% (LightBurn scale) my 60 Watt tube has its maximum penetration in an acrylic block, after that the effect actually goes back a bit. If I remember correctly it corresponded to 18-19 mA. My (self-determined) max is 16 mA and if I wasn’t so anxious to mess with a screwdriver in my power supply, I would have reduced the actual output with the small poti that is in the hole. This is what should be most correct because you thereby reduce the current itself.
I expect that @jkwilborn can give you a good explanation and guidance regarding adjusting the power supply.
Remember to switch off the power and wait to deal with the machine until possible capacitors are discharged
A K40 is a toy compared to your 100Watt machine. However, I don’t know this brand either.
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