Another Dead Laser - Warning Thread Contains Swearing!

[Dr Laser]

Shit, Bugger, Arseholes, Piss, Cock, Fart !!!!!

O.k. So, here's the situation...

About a couple of weeks ago I was adjusting the focus on one of my dual Maxyzmodules, I had the projector on but no laser emission, i'd twiddle the focus ring a little, power the laser up and check focus, then power down and adjust some more etc. Anyway, suffice to say I accidentaly grounded the diode - my fault entirely a momentary error of judgement cost me the diode and I raise my hands up as it was entirely my fault. That's now been sent back to Chuck for repair.

Fortunately I had a spare Maxyzmodule of the correct polarisation, so I stripped down the projector and fitted this. It worked fine and i've been running the projector earlier in the week for a couple of hours or so without problems.

Fast forward to today... I switch on my projector and it doesn't look right, not enough red. I take the lid off the projector and the replacement module I fitted has died. WTF, It was o.k. now it isn't... What is going on???

We've got the UK meet next week and i've got my first big public show (250+ peeps) on the Tuesday of the week after, I could really have done without this right now.

So, I'm getting seriously hacked off with the fragileness (if that's a word) of diodes. What (quick) options are there for me to move away from diodes to DPSS, I guess it'll have to be 671nm and I guess i'll have to up the power to get the same brightness.

Any suggestions as to where I can get something - Quick???

I've emailed Chuck and hopefully he'll be able to get my original Maxyz repaired and returned fairly quickly. In the meantime I could do with a supplier who can get something to me FAST.

Now don't misunderstand me here, i'm not complaining at Chuck at all, he's brilliant and turns stuff around very quickly. The problem is the time it can take to get stuff from the States to the UK by postal service. If I can get a decent DPSS solution, i'll put the Maxyz into another projector along with my other 'spares' and then i'll have a spare projector just in case anything else goes wrong. I guess it must just be something about me and diodes, we're not compatible

Jem

Firststable diodes have to be isolated so it's impassible to ground them. Second if it's so easy to kill them maybe the manufacturer have to spend more time on modules, making them more reliable. Good diods from big manufactures don't have any grounding problems. Long time ago I used to have a 200mw tube 635. It had to be wrapped in insulator to be mounted on a bracket. WFT? Guess what I was adjusting the focus and it blowed up. Since that time I gave up on cheap stuff and moved on to CNI. (or now Laserwave as well) They are well made. No need to move to 671...or of cuz you want to sell your car.

[Jem]

Just a quick update...

Thanks to the extremely helpful folk on the forum (you know who you are), i've managed to (hopefully) get the situation resolved. I say hopefully because the solution is in some part dependant on UPS or a similar courier doing their bit and getting the stuff to me quickly.

I'll give another update a bit later once 'the solution' arrives. But suffice to say a HUGE thanks to all involved.

Looks like I 'may' have full power red for the UK meet after all

Cheers

Jem

[andy_con]

great news,

robin is lending me a green module for the meet so i should have full colour as well.

[allthatwhichis]

Dammit... Now my red died too. I can't think of anything I did to kill it. I was only making some abstracts, my green's fan started to make a little whine, so i turned the frame off, closed LD2000, and unplugged the green to make sure it was the green making the noise, it was... I powered everyting back on, with no noise from the green, but my Maxyz was... is way dim now.

[Jem]

Whoo Hoo...

Problem solved... Repaired Maxxzmodule arrived yesterday (Friday). Unfortunately I had to work all day in my 'proper' job, so fitting it is a task for today. This means I should be on full power for the UK meet.

Jem

[buffo]

Cool! Glad Marconi was able to turn it around for you so quickly.

Take lots of pictures at the meet, Jem! (And be *very* careful fitting those new maxyz modules into your case... Don't want to blow the set before the meet!)

Adam

[andy_con]

there will be shit loads of pics dont wory

[Jem]

New Maxyz are fitted and working well. I had a bit of difficulty aligning them, but they're fairly close now, at least close enough not to be too noticable. I'll finish the alignment when I have a bit more time.

Anyway, it's time to pack up now for tommorrow.

Cheers

Jem

[andyf97]

Was reading this topic with amazement.

So a PBS cube being to close to the diode causing reflection back to the diode and possibly overloading it, basically killing itself. These PBS cubes are AR coated for the wavelength used?.

From what I have seen in all major laser projector manufacturers using multiple diodes, the diodes are isolated from grounds, earths and other metal bodies usually on an insulating base plate and even sometimes with the Tec cooler.

Another thing, some diodes have a little socket that connect the diode to wires, if these sockets are loose or come loose due to music or vibration just for a short moment while the diode has power, some diode drivers can kill the diode when the connection is re-made. Don’t know exactly the cause but I assume its surge.

Static can also kill the diodes but i read newer ones are having protection.

Diodes needing to be kept as cool as possible?, actually starting the diode from really cold to fully on can also damage the diode. So some producers have a TEC cooler that also has a warming feature. Some diode drivers have a soft start feature to not allow the diode to fully power until the diode is already warm / temperature stable.

I think all suppliers of diode modules should internally isolate the diode from its heat sink, while this causes other problems such as the obvious heat; it prevents the diode from shorting out. After all they are selling a product that should have at least some protection. Maybe mount the diode in some thermal plastic first before it is fitted into the heat sink housing. Ok so the next step is to prevent over heating, a temperature sensor / thermal resister dropped into a silicone filled hole in the heat sink for feedback to the drive circuit, then a TEC also placed under this heat sink to keep the temp constant and stable. Some fancy little circuit that toggles cooling/warming restricts diode current until a temp range is met. This means having a dedicated driver board such as a die4drive with the additional circuit for temp control. IT might need a small microcontroller to do this but it’s worth the extra cost to have more protection.

For those diodes with the little header to connect the wires, it is best to not use the header and solder directly to the diode. Of course use very flexible wires or you will likely snap one of the diode legs eventually after experimenting for a few hours. I neat way is to put some heat shrink tubes over these wires and push them right up to the diode base. Then glue them in place to form a kind of cable strain.

I didn’t see one of these new diodes from the Pioneer yet but it looks easy to damage the chip or connecting wires, here I suggest using a short barrel that creates a protective wall around the diode, just a short one that will prevent something from hitting those tiny bits but still allow air to flow freely around the chip.

Ok, so if there some electronic wizard out there that can expand upon the die4drive board it will help many people. I am thinking to make a similar project but as always my time is very short to sit down and create, however I will assist if required.

My god, I just looked how much I wrote, I must be crazy.

[steve-o]

I found it helpful (for future use) to use low power as Chuck suggests ( Chuck, you need some hydrocodone- my back/ disc/ sciatica went away today for the 1st time in 3 weeks and feels great) for initial alignment and off center the bs cube slightly (only a couple of degrees will save a diode.. here's my quick &(lousy) sketch::