What makes these work is really the lens. An offset beam will produce a slanted cut. Head setup is very critical.
Most lasers have somewhere around 8mm beam… if you have a 20mm mirror, it’s only 14mm wide in one direction as it’s at a 45 deg angle. You end up with 14mm - 8mm = 6mm, you end up having only 3mm slack on each side for error.
Center of the hole/lens can be misleading as it was with my stock head.
The head mirror must ensure the beam goes down the center of the tube. Sometimes this isn’t centered.
The problem with most of these, is the lack of adjustments with the head.
IMHO… A W4 100W RECI… a good tube, like this, should have an mtbf of about 10k hours as they specify at operating current.
Most good tubes give you both an operatingand a do not exceed current. The tube gases get broken up quickly if you run above the do not exceed value. Sorry, don’t know the physics here.
The specification would be worthless if the mtbf is based on something other than suggested operating current. If you had to run 70% current to make it last the listed mtbf what would that mean? Unless they note different conditions of operation …
This advertisement for a K40 it’s noted mtbf/current relationship. Even in the best condition, tube life with these are not what I’d call even reasonable.
However all this is moot if you are not calibrated so that 100% power in Lightburn equates to 100% power or current. Lacking a mA meter (and a watt meter) you don’t really know what you have.
Since Ohms law doesn’t apply some tools are needed else assumptions must be made…
It’s up to us as users to put all this together and make something of it that makes us comfortable…
Hi I have 70 watt CO2 and for 1/8” Baltic birch I use 15 speed and 50 power. Make sure your clarifier is clean, mirrors and etc. Examine your lens, don’t just look at it while still in the housing. Take it out and inspect from both sides. I once looked at my lens while still in the housing and it looked okay but cutting was still crap. Took the lens completely out and examined it and found a burn spot on it and also that it was pitted ever so slightly. Best of luck getting it going.
Hi, You can safely run the tube over 80% power as long as your not exceeding the max rated Ma. You really should have a Ma meter installed it’s the most important reading for tube safety, you cannot go from the power setting.
I have 100w EFR X4 tube on my small laser and can run that upto 95% power (gives recommended 28ma use)
I have 150 EFR X8 tube in my big laser and can only run that at 75% power (as that gives also 28ma recommended daily use), for thicker jobs I can push to 80% power (30ma) as that is also ok in short stints.(max is 34ma on this tube)
If my mirrors and lens looked like yours I would just replace with new.
Fyi I use 4" lens for cutting and 2" for engraving. my 100w machine cutting 4mm ply = 30mm/s @ 95% power (1 pass)
Hmmm
I have a 60W Omtech Co2
I cut 3mm veneered MDF 7mm/sec @ 50% power. 13Ma. One Pass
I also cut 6mm veneered MDF 5mm/sec @ 50% power. 13Ma. One Pass.
Granted I am not trying to do several hundred pieces or more per day. For my use I see no real reason for running my machine at 24Ma which is recommended.
Have had my machine two years with no noticeable decay for my tube.
Willkommen to the club
I don’t think it will work today, with the knowledge we have gathered or said in another way, we will be aware that the tube/machines are falsely described and deal with it in a different way .
(I knew it from the start and accepted it, but think it was not honest marketing from OMT and not necessary either. They overrated the tube but stated the correct physical measurements,)
Jack, what are your max power values on e.g. a 3 hour continuous job? (in mA shown)
I don’t think I’ve ever run a cut job that lasts that long, which is the only time I need to run higher power levels.
My tube has a working current of 20mA and a do not exceed of ~23mA. It actually reaches it’s rated 40W at ~18mA. My lps is set to limit at 18mA equaling maximum wattage out. No point in running more current through it with no benefit.
My percent power is based on 40W at 18mA. It’s reasonably close to linear for a tube, 50% power is very close to 20W or about as close as I can interpret the Mahoney meters analog dial… I didn’t use the Dohickey for this… Should try it for fun
I can lase at 9.8% power, so the Ruida is setup for 9.8 - 99% power limit on the pwm output.
It’s well within it’s operating range to run it at 100% power, if I need to, which is rare.
During extended cutting of 5mm sub flooring I’m usually in the mid 80% power range and reading ~12kV on the anode. I don’t usually run it, then check the wattage out.
A majority of my use is engraving, so I’m running very low current readings which relate to around 4 to 8W out, seems to do what I need it to do.
Doing engraving, you can only read the RMS current and without knowledge of the actual on/off time you’re stuck with interpreting the RMS value reading… Only a scope will allow more details. I have outputs on the side of my machine to plug a scope into… red box on right … this is a relatively old photo.
I can recognize that (with minus 2mA for my machine)
When I have a day’s production, it is with (my) max power. Alternative will be longer time and with less power…I mainly cut.
What I don’t understand is that the official mA “recommendation” by the manufacturers is set so high when experiments show that there is no increase in efficiency above 16-18mA. (for 40-80? Watt machines)
Probably most of us have done the necessary tests and found their optimal process values. And those who don’t, probably don’t have an ammeter either and don’t have these worries at all
I’ve tossed around in my mind many times… I don’t know for certain, but…
I believe it’s calculated by the physics of the tube.
Mainly because I doubt they run your tube at a high current rating and test the gasses.
I also doubt they do 10 tubes, test the gasses and give you an average.
The physics will give you an exact value for the perfect tube… that’s also rather unreasonable by how they are constructed, embedding a pair of accurately paired mirrors in almost molten glass. Too many variables in real life manufacturing and no real way to test them once they are completed.
It also doesn’t help when we buy stuff off the Internet and it isn’t up to par… I saw a photo somewhere of the new 80W reci tube a guy just got for a replacement… it was marked 75W on a reci tag… Clearly a grade B tube sold at a reduced grade A price…
You got me on how this is actually done… but I have found that when I got a replacement from Cloud Ray of my 50W (ha ha) it produced the advertised output.
It might also be that the grade B tube will get to that wattage when run at higher current levels…
In the end, I’m clueless, just like the rest of us.
Hey Jack, it’s 10 minutes before 9pm here, we’ve eaten our Christmas duck and given ourselves the presents…
I just looked for specifications of 60Watt laser tubes at Vevor and OMTech and was very surprised. Their max mA recommendation is down to 15 to 18 mA!!! it is a significant change in their description of tubes up to 70Watt.
All the “cheap” tubes up to 70Watt only have a half year warranty or 2000 hours at max 40%!!! it is a clear indication that these are B or C goods. If you choose to use your tube with 70 to 100%, there is only 800 hours expected life, it is an official statement that shakes me on the one hand and shows me on the other hand that their old manuals and sales advertisements are lies.
Maybe we should change our CO2 machines again for a Didolaser machine with 100 Watts (have seen the ad!!!)
This sounds more like how it’s wired than really truthful about a gas tube.
Yep, warranty is very shy (4 months)… I have the CR45 tube, it’s 40W at about 18mA. I bought it as a 40W tube, not a 45W - 55W tube. I have severe doubt about the 55W value for it’s length. I decided on 40W and quit when I got near that point. It kept going up, but it was flattening out.
I’ll have to double check these… when it warms up a bit outside… most of the time I’m using the fiber inside…
Both of these are from Cloud Ray. Notice they don’t state mtbf on these.
The descriptions from Cloudray seem realistic enough to me. And yes, our machines are tools and bought to use them.
A 4 month warranty is in my eyes just like they don’t trust their own products.
Some companies also no longer provide a guarantee for transport damage. I will never buy from a company that does not insure their delivery.
But the guarantee rules in the EU are a completely different matter. Not even Apple can run from their 2 year warranty obligation here. My airpods pro broke some time into their second year, I had them exchanged for new ones.
I have not heard of warranty cases regarding CO2 tubes, but it could be interesting in real life.
on them.