Sold (UK) Free:   Electrox Cobra 150w YAG laser (non fuctioning) - Page 1
Forum section: electronics / general

author: billtodd
author_rank: Contributor
timestamp: June 11, 2024, 05:16:32 pm
content: Electrox Cobra laser engraver (XY mirror scanner) 150w YAG (infra red) for parts or repair (UK collection only)This powers up but fails with a 'low diode power' error*, so I assume it requires a replacement pump diode. the manufacturers diodes are no longer available, but it may be possible to retro fit another type[* it is just possible that it will work at reduced power, but before I thought to try this, I unplugged and disconnected the laser head. The pictures below show that the pump diode is not completely dead]This consists of a mirror galvo XY and a Q switched YAG laser head, a 8U(?) 2kW power supply control unit and a 8U (?) water cooler/chiller unit. These are housed in a substantial 19" rack unitI have a controller PC with software( but, if you want this I'll have to remove some files first so let me know)It is collection only, from colchester essex. If the power unit and cooler are removed from the rack it all should fit into a large estate car.

author: Stray Electron
author_rank: Super Contributor
timestamp: June 11, 2024, 07:49:17 pm
content: A strong word of warning here for anyone that's interested in this:YAG lasers are extremely dangerous to your eyesight!If you don'tknowwhat you're doing, don't mess with this or you WILL probably destroy the retinas of your eyes.

author: billtodd
author_rank: Contributor
timestamp: June 11, 2024, 08:01:13 pm
content: QuoteYes indeed. At 150w this is extremely dangerous to all parts of a body ! It is a metal cutting laser.You'll have to convince me you are competent before I let you have this . There may be tests , interrogation and possibly torture .'...No Mr Bond i expect you to be safe...'

author: _Wim_
author_rank: Super Contributor
timestamp: June 15, 2024, 05:18:54 am
content: Quote from: billtodd on June 11, 2024, 08:01:13 pmVery nice offer, but scared of the test & torture (and also because it a little to far to come and pick it up)...

author: Slh
author_rank: Regular Contributor
timestamp: June 15, 2024, 05:37:39 am
content: Shame, my car's not big enough and I don't really a need for a big laser.I used to work on power supplies for Q-switched YAG lasers. Ours also had a feedback photodiode in the head - if that's moved or the connectors corroded then you might get the same fault. It might be a cheaper fix than new laser diodes (but don't rely on that)

author: billtodd
author_rank: Contributor
timestamp: June 15, 2024, 09:42:52 am
content: Quote from: Slh on June 15, 2024, 05:37:39 amI know little about these , hence giving it away.I tested the pump diodes with a current limited PSU (ISTR about 8w in the pictures) would you expect to see missing chips at that kind of power ?Also, would you expect a 'diode fail error' if it was unable to reach requested power , even though diode was sort-of working - i.e. do the PSUs ramp up to provide requested output, to compensate for diode fade ?

author: billtodd
author_rank: Contributor
timestamp: June 15, 2024, 09:44:32 am
content: Quote from: _Wim_ on June 15, 2024, 05:18:54 amBelgium's not that far away , and I wouldn't torture you too much ;-)

author: billtodd
author_rank: Contributor
timestamp: June 15, 2024, 11:48:12 am
content: Great !We have a prospective new owner :-)

author: Slh
author_rank: Regular Contributor
timestamp: June 15, 2024, 05:46:52 pm
content: To be honest, I was mostly playing with the flashlamp pumped lasers so don't know diode pumped ones too well. Looking at the photos I see a few missing diodes but not many and I don't know what the typical people is like or if 8W is enough to light them all up.

author: artag
author_rank: Super Contributor
timestamp: June 15, 2024, 08:14:29 pm
content: I have a YAG laser that's flashlamp pumped. It's pretty much the same as the one Photonicinduction tore down after destroying his camera.The flashlamp supply is a bit of a beast and I've wondered if it's possible to replace that with a bunch of LEDs.Is it ? Has LED technology left xenon that far behind yet ?

author: billtodd
author_rank: Contributor
timestamp: June 15, 2024, 09:29:58 pm
content: Quote from: artag on June 15, 2024, 08:14:29 pmI suspect they are laser diodes rather than simple leds. The driver psu is substantial, several Hundred watts (upto 40amps i believe). . the YAG block has a port on the side for the power sensor to monitor the diode output.

author: _Wim_
author_rank: Super Contributor
timestamp: June 16, 2024, 04:40:33 am
content: Quote from: billtodd on June 15, 2024, 09:44:32 amI was considering it, but it is still quite a travel and a hassle since Brexit. And I already own a working pulsed YAG laser with galvo's, and really do not need another project (not that that has ever stopped me)....

author: billtodd
author_rank: Contributor
timestamp: June 24, 2024, 01:30:08 pm
content: Picked up today by Dan a seriously nice guy.Under torture, Dan confessed to being a laser expert , so the machine is in a safe pair of hands (as soon as his thumbs heal).

author: danielbriggs
author_rank: Regular Contributor
timestamp: June 24, 2024, 07:30:32 pm
content: Well, I’m back home after a few hours drive back from Bill’s. What a gentleman!I love this forum for its friendly community all in the spirit of all things electronic; Bill’s an absolute credit to this!It won’t be for a couple of weeks due to work commitments but I’ll make a thread about the repair and getting this back up and running again.It seems an exceptionally well made unit, and Bill was kind enough to send the original control software with it.I should have most of the tools lying around to run this up safely and quantify how much power it is outputting. If it needs a bit of tweaking, I’ll see what can be done about that!Thanks again and speak soon.Dan

author: _Wim_
author_rank: Super Contributor
timestamp: June 25, 2024, 04:57:56 am
content: Quote from: danielbriggs on June 24, 2024, 07:30:32 pmFully agree! Very glad to see this laser came in good hands!Quote from: danielbriggs on June 24, 2024, 07:30:32 pmLooking forward to this. Makes us all feel sorry we did not pick it up ourselves!

author: Brumby
author_rank: Unknown
timestamp: June 25, 2024, 08:56:18 am
content: This thing did catch my eye - but the distance to collect put me off. (Also, because my laser expertise is limited to a 120W CO2tube.)I am keen to see what becomes of it in the hands of someone who knows their way around it.

author: danielbriggs
author_rank: Regular Contributor
timestamp: June 28, 2024, 03:57:58 pm
content: Hello EEVBlog!I hope Bill doesn't mind me semi-hijacking his thread + posting in here [if it's a problem, I can move this to a new thread].I've had a couple of evenings fiddling with the laser.Bit-by-bit progress has been made.In no particular order:- New power cable fitted to chassis.- Umbilical reconnected between the head and the chassis; (hose lines reattached; Q-Switch, diodes, galvo power + data etc.)- PC was dead; so replaced the PSU and got all that up and running again.- Refilled with DI, fixed a few leaks, polished the water for a while and got the chiller running fairly happily.- Worked out all the interlocks and bypassed the missing bits it was looking for (enclosure switches and other misc. interlocks).+ managed to fire it up!The chiller seems very fussy about the temperature setpoint. It seems to be set manually (anything from 18-26˚C) but will error out if it stays "too hot or too cold" [the exact error on the console] if it stays at a given temp for more than 10-15 mins, it doesn't actually tell you what temp it's looking for, or should be set at. Bill I don't suppose you remember what it's set point was? Not a problem if not, by process of trial and error I can find the point it's happy with / looking for.So the slightly negative bit: try as I might I couldn't get the software / unit to enable the diode driver after trying a whole pile of things.I can't confirm this, but it seems the controller has decided the unit needs the laser diodes in the head replacing (maybe some sort of EEPROM bit set / e-fuse etc?) as this error immediately comes up when the unit is started. However there doesn't appear to be any intelligence between the head / chassis where this data could be read from (no EEPROM I can see etc.).It's almost as if the controller has seen this error previously and now refuses to run the diode driver up until a service engineer comes and does a secret dance to make it think it's operational again.Refusing to give up, I traced the control lines from the DSP card to the laser diode driver, and lifted the signals, + manually injected the signals it will have been looking for (12V enable line, and modulated 0-10V analog for LDD power).And... RESULT!This is very much a "jump start" approach, and further work is needed to get it working properly; and then to assess it optically + tweak as required.So all the major components, electrically, chiller + optically seem to be behaving in principle.But I'm happy I got it to do "something" relatively easily.Anyway,Thanks again all + have a nice weekend Bill.Cheers,Dan

author: billtodd
author_rank: Contributor
timestamp: June 28, 2024, 08:45:25 pm
content: Great stuff DanI'm truly glad you've been able to get something out of it. In addition to the focus slide , we forgot to load the door for the cabinet, so if you find yourself in the area feel free todrop in and collect them.As to high jacking the thread : I'm not worried , but the mods might object to it being in the buy/sell forum . Perhaps a new thread elsewhere with a link here?QuoteSorry, They've got me on Statins, I can barely remember who I amBillQuotetales from the repairman...(Different laser engraver)"Bill, can you look at our engraver..." The 'works' has an overpriced laser engraver (two actually , one on another site) it works ok but support has been crap and now they are insisting on an overpriced service contract etc.etc.My initial guess was psu, and ,sure enough , on inspection the neg15v was dead. So, off I trot home , and order a replacement. At base, my brain catches up and I realized I should have checked for shorts, but 30w is usually enough to generate smoke and none was observed.A day later I have new psu and pop in to the works to fit it . I remember to check for short and, bugger, the servo galvanometer , the only thing fed by this supply is the fault. It is a bastard to remove, but 'in for penny, in for a pound ' I hump it back to the bench. Service replacement for this thing is probably in the £1000 region , so worth taking a look.On the bench, I quickly determine the X axis driver is the problem , and take a WAG that the amp chip is dead , of course none of my usual, or unusual suppliers have stock, but eBay comes to the rescue and a replacement ordered. The driver board is a compact double sided surface mount design, so is a sod to work on. The only safe way to remove the chip is the break it and pull the legs one at a time. Needless to say , this process exonerates the chip and I soon find the culprit is a large surface mount capacitor (in my defense m'lud, aluminium electrolytic caps don't usually go short).The buzz words of 2022 was 'supply chain' so , of course, no one - anywhere, has them in stock, except a ebayer in hongkong ...Weeks later I have the parts (I have never had a problem with HK suppliers , they always deliver - eventually). Fitting the bloody thing on the board is another nightmare, which is why I only replaced the dead one and not them all (I await a bite on the arse).Off I trot back to the 'works' to refit the mirror head (which is as difficult to refit as it was to remove). I power up the machine and sweet FA , nothing powers up . On close inspection the standby supply is on and so suspicion rapidly falls on a 'service' board that weeks before was showing a oddly blank display . Somewhat vexed and very very annoyed, I take the service board back to the bench and reverse engineer it - this little f###er will stop the laser running when its on board battery dies and won't allow a restart unless it is reprogrammed . So, I bypassed it!This was all before Christmas and , since someone was kind enough to give me flu , it wasn't until yesterday (January '23), that I felt well enough to return to the engraver.With the bypassed service board refitted, bingo it fired up, homed responded , to JR's (the operator) instructions , but no visible markers and no bloody lasering. !!#%%## the air was blue . Has the laser died?, Does it need a reset after the 'service' flag? - needless to say we have no information on this machine, I am working from experience only and at this point , I'm out. My throat is sore from three weeks of coughing and my arse is cold from sitting on the floor working on this piece of shit. I retire to the pavilion, injured....At 01:00 hours this morning, after being unable to ignore the elephant, my brain catches up. The laser was working, why should it fail? Could the mirror galvo be kicked off axis? I need to get eyes on the mirrors. So , as I imagined how I might contort myself into a position to see the things , CLICK.I emailed JR..."John,Did you remove the lens cap?

author: Brumby
author_rank: Unknown
timestamp: June 30, 2024, 11:10:02 am
content: Quote from: billtodd on June 28, 2024, 08:45:25 pmIndeed. This is not the place to continue.QuoteAbsolutely the best idea.