Any YAG laser experts here ?

[BillTodd]

I've just been given a pro laser engraver. Its a bit of a monster (150W  @ 1084nm  2.2kW psu with cooler) and broken so I'll probably break it, but I thought I d ask if anyone has  YAG laser experience.

The machine was scrapped with a 'diode low power' fault. I'm guessing this means the 808nm pumping diode has dimmed.

So, how easy would this be to replace the pump

[tom osselton]

There are tons of diode laser heads on Amazon I’d check them out.

[BillTodd]

Under the lid ..

Playing with the software, I noticed a setting to extend pump diode warning time , so I am crossing my fingers that there are a few blasts left in this thing .

[BillTodd]

Well , the extend warning is only a software thing. The diode pump isn't working :-(

I opened the diode pump box and investigated:
The pump consists of 6  laser diode banks each with 25  chips .  Driving it with a constant current supply I can see a good few chips not working .

The voltage across the array was only 9V or so at 2A - given this is driven by a 50A 45V supply , I can see the need for water cooling.

[BillTodd]

BTW these diodes shine down on to the YAG (yttrium aluminium garnet) crystal which is encased in a water jacket for cooling. The red laser light pumps up the electrons in the crystal . When the electrons collapse to their rest state (controlled by a Q switch) they release Infrared photons , which burn the crap out of what ever gets in their way.

[ddmckee54]

At 150W, if you get that beast working you'll be able to cut with extreme prejudice at a high rate of speed. But cut what??  Besides any fingers or toes that just happen to get in the way that is.  (The scene from Goldfinger springs to mind.)

Good luck with the rebuild and watch those fingers and toes.

Don

[BillTodd]

Anyone here (in Uk) want this ?

It's taking up shed space and I'm not going to do anything with it soon, so ...

It FOC to anyone who can collect.

Shoot me a PM if you're interested.

Bill

[philf]

Hi Bill,

I don't want it!

But it's brought back memories of a Quantronix YAG laser we had for scribing semiconductors. It was my responsibility to install and get the process up and running. It needed a lot of cooling water and I remember having to install a leg in the feed pipe half full of air to remove the violent knock every time the solenoid shut off the flow! I'd forgotten about Q-Switches until you mentioned them.

Diamond saws soon made the Quantronix obsolete. It may well have ended up as scrap.

Cheers.

Phil.

[BillTodd]

someone with laser expertise has stepped up from the EEVblog.  Hopefully, it'll have a new home soon 

[BillTodd]

The engraver is now in the hands of Dan from the eevblog , who has already got it working partially.