Need expert input on Argon alignment

[Escher]

Sorry for a new thread but I'm in desperate need atm..

So, my argon is all set, and I can get barely any output.. so after reading and reading and more reading I determined that the tube is a bit out of alignment.

I put a long rod on the rear output side of the tube, and with extremely gentle pressure I can get it to come up to full power... around 40-50mw... but once I remove the rod it drops back out to under 1mw due to the misalignment.

So - I'm paranoid - how much pressure can I apply to tweak the tube back into alignment? I have determined the direction I need the tube tweaked... but I'm super scared to put too much pressure on it and break the seal..

HELP!!!

*** See updates at end - Head is now running at approx 35mw with 5 lines consistently.

 

[bloompyle]

What make and model is your Ar?

If it's a tube with a brewster window, and it likely is, then you simply need to adjust the Y for the OC. This simply turns the external mirror to align it. Unlike HeNes, the mirrors are external to the tube, completely unattached. They are inside mirror mounts designed to let you alter alignment.

So if it is a tube with brewster windows, and external mirrors, it will 100% safe to adjust the mirror mounts to align them

Just requires a screwdriver to turn a screw or two

 

[Escher]

Unfortunately they aren't external..

Its A JDSU 2214 series head.

After a few more hours research into Sams FAQ I read that I can add a locking collar to the cathode end and use the setscrews to tweak... I'm planning something like this.

I spent about 4 hours tweaking it and got a weak beam in 488 only without having the adjusting rod attached.

If I attach the adjusting rod and apply gentle pressure I can get 5 lines at around 30-40mw of output (light output measured via dvm) and adjusting tube current.

The other issue is I think my fan isn't pulling enough air, or the cooling fins are clogged in the tube... as even when I use low amperage (around 5-6 amps) its doing a thermal shutdown after 3-4 minutes.

So - in a nutshell:
Good tube and PSU. Possible thermal issues causing overheating. Rear optic out of alignment will require some mods to tweak..

 

[bloompyle]

Even if they aren't external, they can be adjusted.

Just like you can adjust HeNe mirrors. That is, unless it is fused directly to the tube. HeNes have a bit of metal between tube and mirror, that you can bend to adjust the mirror alignment.

Looks like you've got it figured out though.

The output of the fan should be warm, like a shower, but not hot to where it burns you. Once it plateaus, you're good. If it's a consistent increase, then you need to get a better fan.

 

[Escher]

I think I've got something taht will work for now.

I took a velcro cable tie and wrapped it around the metal output tube and then ran the cable through one of the access holes.

Now, as it runs I can gently pull on the cable tie and adjust the alignment to get more output.

I then attached another piece of stickback velcro to the outside of the tube and I can "tack down" the cable tie when I tune the output to max... seems to work pretty well and I can get 5 lines consistently.

I can run on idle at 3-4mw without much issue... but if I go up to 20-30mw it will shutdown after about 3 minutes. So, I think a larger fan or a second inline fan is needed.

Here is a video of where I'm at and the setup:

Argon ion laser tuning - 1 - YouTube

***** Update

I think I got the thermal issues solved for the most part. I added an 8" inline duct fan as well with a reducer and now I'm not seeing any thermal issues. I ran for over an hour. I would idle for most of the time but did several 3-5 minute runs at 33mw.

It now looks like a Saturn V rocket with the two reducers and 2 inline fans...

Looks like 5 lines is all I'm getting out of this head... I popped the end bell and had a peek at the hour meter - somewhere around 7k.

Good news is its starting reliably every time now and giving me consistent results. The fifth line shows up right around 20mw.

I did play with tweaking the tube a bit more and 33-35mw is about the best I can get out of it. I think the 40-50mw yesterday was because it hadn't been run in a long time... now its settled in and is running consistent in the 30's no matter what.

So - long story short - $100 for the laser unit, $33 for the 6" inline fan, $40 for the 8", and $12 for the reducers.. $185 total for 35mw multiline... not bad I'd say.