Firing up a little argon?

[Things]

I'm glad to see it working as well

At max current (As far as I can push the PSU before it starts complaining about not getting enough power), I could spot about 6 lines. I didnt count very carefully as I had a camera in one hand, a CD in the other and had to do it quickly so it wouldn't overheat

What kind of CFM rating should I be looking for in a fan?

EDIT: Youtube video: http://www.youtube.com/watch?v=jm6KS4eV0xU&feature=channel_video_title

EDIT EDIT: Would a fan like this work? I'm not sure if its actually 200CFM, but it draws 12V at 3A, so it's pretty powerful sounding! http://cgi.ebay.com/Sunon-120mm-200CFM-12-Volt-DC-Fan-PSD1212PMBX-Powerful-/320614923916

Or maybe even this? I know NMB Delta make the crazyfans from the projectors, so wouldn't doubt the airflow rating: http://cgi.ebay.com/New-DELTA-240-CFM-TFB-Series-12v-120mm-fan-sleevedw-RPM-/140454682040



Cheers,
Dan

 

[Things]

OK well, I had a chance to ramp it as far as the PSU could get power, and got a good pic of all the lines. I'm happy with that

 

[daguin]

Ah well, I'm happy its running now

Still takes a little effort to get it started, but it always starts when I ramp up the current a bit now.

How long should I leave it idling for to try get the pressure back down?

Got some vids coming, but a few pics:

Beam is a fair bit greener in real life.

Will the beam change back to a more bluish colour as the argon gets itself back into line?
Also, it seems I'm going to need a much more powerful fan. Does anyone have any recommendations for a (preferably cheap) 240V. very high flow 120mm fan?

Cheers,
Dan

SWEEEEEEET!

The multi-line has a fair bit of green in it

RE: a fan -- How's your shipping budget holding out?

Peace,
dave

 

[Things]

Well, I put it all back together into its case, and it started using its inbuilt igniter

It's now out in the garage idling for its very long burn in

A few more pics:

My original fan seems to handle it OK on idle, considering ambient temp is already around 28C, shining the IR thermometer at the fan shows about 55C.

Dave, is it a 240V fan? What would you guess shipping is? Post office is gonna get to know your name!

Big thanks to daguin for hooking me up with this beautiful laser!

I'll need to find something to send you in return

Cheers,
Dan

 

[daguin]

Well, I put it all back together into its case, and it started using its inbuilt igniter

It's now out in the garage idling for its very long burn in

My original fan seems to handle it OK on idle, considering ambient temp is already around 28C, shining the IR thermometer at the fan shows about 55C.

Dave, is it a 240V fan? What would you guess shipping is? Post office is gonna get to know your name!

Big thanks to daguin for hooking me up with this beautiful laser!

I'll need to find something to send you in return

Cheers,
Dan

Very nice :san:

I am very pleased to see one of these running. Jayrob may want to pick your brain about this

Usually, once you get them started, they will stay with you (as long as you remember to do your maintenance runs)

This is the blower I have for this application. This is NOT my auction. It is just the same model blower from McClean Engineering

Mclean Blower, No.7162-5003, Type U6281 1PH, New ! - eBay (item 230523797103 end time Apr-06-11 10:15:12 PDT)

Shipping looks like:

$60 for Priority Mail

or

$70 for Express Mail

Same deal as the other components?

Peace,
dave

 

[Things]

Done

Not quite sure how I'm going to attach it to the vent on top, but at least I can pipe the heat outside

Cheers,
Dan

 

[Things]

Argh, bad news, it's not starting anymore

Gone back to doing what it was before

I'll rewire the whole thing again and try it back on the other starter, after that, the current is going up and that thing is gonna roast until the pressure is back

EDIT: OK, it still starts on the external igniter. Really weird because it was starting fine off the inbuilt one easier.

 

[daguin]

Done

Not quite sure how I'm going to attach it to the vent on top, but at least I can pipe the heat outside

Cheers,
Dan

You will have to fabricate some sort of adapter. One way is you can make something to hold it directly on top of the laser. This makes the assembly more "compact", but adds some vibration to the laser. The other way would be to run a bit of dryer vent hose from the laser to the blower.

I use the second method. My blower is built into a "box." With the box/hose system, I can use the same blower for many different models of lasers.

Peace,
dave

 

[Things]

It seems as though about 6 hours of idling wasn't enough to bring the pressure down, at the moment it's being just as hard to start as the other night

I think I might have to try start it on the big igniter, then just run it into the ground until the pressure drops.

Does anyone know how I could increase the repetition rate of this little ignitor? It seems it'd work if it went faster:

Cheers,
Dan

 

[HIMNL9]

Careful, playing with that circuit may end in a damage of the ignition system.

The elements that gives you the discharge rate are the value of the capacitor, the voltage and the value of discharge of the gas discharger (the component marked "epcos" in your pic, and the value of the resistor that charge the capacitor ..... this a resistor charge the capacitor, and when the voltage on it reach the discharge value of the gas discharger, it close the cap on the coil, generating the high voltage spike ..... you can accelerate them changing the capacitor value (less capacity need less time for charge, but gives you less HV and shorter spikes), or changing the gas discharger with one with lower value (it trigger before, but again, the result is less HV in the spikes), or changing the value of the resistor that charge the capacitor, so it charge faster (it's usually a high value resistor), but in this case, you need to check that the rest of the circuit can hold the extra discharge rate and the more current charge of the capacitor, otherwise you can damage the exclusion circuit.


EDIT: PLEASE CHECK ONE THING ..... that thin wire of copper that you can see in your pic, in the right part near the write "UT 301" and the white wire ..... it's part of the circuit, or is just a piece of wire lost inside ? ..... it seem touching the cathode terminal of CR 305, but it does not look part of the assembly, and if is not part of the circuit, it risk to short circuit something, if it move around .....

 

[Things]

Well, I have the tube running again now, I started it on the other ignitor. I'm kind of worried it may have developed a leak or something, as it was rather hard to start, and the beam doesnt seem to get as bright as it did before, before the PSU trips out. Or is this just because of the changes in gas pressure?

Just having another look at it running, when I turned it down to idle, the dot was only just visible. I turned the laser off for a little while, and restarted it and the idle dot looks normal-ish, maybe just a little bit duller, but the main thing I noticed is there is a fair bit of light coming out the back of the filament mirror? its a purpleish/orange colour, and also at the front of the tube, there is a little clear spacer that is normally glowing a UV colour, and it still is, but there is a bit of pink there now?

I think I've heard somewhere that pink is a sign of nitrogen, so I'm really worried

Could someone who has done it before, give me an overview of the burn in process? What the dot does as the gas pressure is going back down, is it harder to start like I describe? Different dot/filament colours? How long should I run it for? etc

The tube voltage is around 84V, which seems kind of low ...

Just reading Sams FAQ, it seems that low gas pressure can result in lower power and less lines, rings around the beams, and low operating voltage. Kind of worried the tube might be dead

Problems I'm experiencing now:

Filament (appears) to be brighter - can't tell for sure
Dot is not as bright as before, on both idle and current up
Only getting 3 lines before the power supply gives up, instead of 8 earlier
Tube voltage is really low - 84V
Dot seems slightly unstable
Appears to be a bit of pink light out the back of the filament window, as well as just before the aperture

I also just read this on the FAQ: "An argon tube with clean multi-line optics installed that only emits the 488 blue line is a dead giveaway for low pressure and end of life"

I'm pretty convinced the tube is gone, it meets almost all of the criteria for a low pressure tube

Cheers,
Dan

NERGED:

Just fired up the argon again and we're down to 2 lines, with a very dominant green line. It now matches with the description of low gas pressure, and with these small tubes, end of life

It was fun while it lasted

Not sure why it died off so quickly though, this morning it was running beautifully with around 8 lines.

MERGED:

I fired it up again from cold this morning, and I think I can only see a 448nm line, and a slightly lower wavelength line below it.

Looks like I'm on the hunt for a new tube

 

[Things]

I just fired it up again tonight, and when it first fired up, I had 3 lines, and the brightness was OK

Though, as the tube warmed up, the lines started dropping off, and so did the power.

These are the only 2 lines that still lase

And the line in the red circle drops off once it warms up.

At this point, there is only 1 line left lasing, the power output is about the same at full current as it was idle BEFORE it started dieing, and idle doesn't even produce any laser emission, just a purple plasma glow.

So it seems whatever the problem is, as the tube heats up, it gets worse ...

I'm not sure, but I think I'm noticing a lot more pink glow from the mirror behind the filament as well. Signs of gas contamination or something maybe?

Apart from Daguin, so far I haven't been able to get any reply from any of the "gas laser gods" over on PL, so I'm lost as to possible problems.

 

[Things]

OK, I think I've just made a breakthrough!

While it was running full current, I grabbed a peice of plastic tube and lightly tapped the back mirror mount, and saw a flash from a green line. So I pushed down on it a bit harder and lines started reappearing!!

Only problem is, there is no obvious way of adjusting the mirror mount, and it;s clearly going out of whack during thermal expansion. Anyone know how I could make some adjustments? Maybe some nylon string and a few screws to pull it down lightly?

All my lines are back

Sooooo happy to see those lines again!

Cheers,
Dan

 

[Experimentonomen]

I borrow this thread, i finally tried to fire up my argon again after sitting in the basement for almost a year, and it wont start!!

Ignitor does lase it just as things's laser did, but it wont stay lit and from time to time it fires and stays lit down the capillaries.

I was going to sell this thing byt that prolly wont happen until it reliably ignites again.

This thing used to light up on the first or second ignitor tick :/

 

[Things]

Yeah, they're known for not starting after a while. Mine is being a bit of a pain to start still.

it's odd, because I can run the tube until the voltage stabilizes out at 84V, but it still refuses to ignite even after sitting for a night. And it still won't start at idle current.

Sometimes if you turn the current up, it'll really try to start, and might even lase for a second or so, but after that strike, it won't want to start again.

 

[Experimentonomen]

And my argon is alive again as well

Built a buck converter style psu and it fired right up.