Help me disassemble HeNe laser

[Bratan]

This is the laser I have:

Close-up:

I would like to carefully remove outer shell, but don't know how. Tube is sealed, there are no screws other than ground.
I can easily remove this part (it holds extra lens):

, but there's nothing I can easily open under it...

If anyone did this to a similar laser please let me know!

Here are more pics just in case:

 

[Trevor]

Why disassemble it?!

Just buy a bare tube on ebay, that housing is in great shape!

If you're bent on disassembling it, first unscrew everything in sight. To get the end cap with the cord off, slide a knife (that you don't care about) around in the crack until it starts to pull away a bit. Then you can work on it with your hands and other tools to pop off.

The front bit I've never seen before. Unscrew all the screws and try to get a feel for how it's attached. It may just be pressed in, or it may have wires running to it. I'd just take the screws out and pull on it some - but it's risky. The ballast resistors are probably in the front bit (Siemens did that on my green HeNe) - so it may be wired to the tube.

When you get both ends off, you'll find that the tube is still immobilized. The holes around the housing that have white material in them are the places where silicon adhesive was injected into the housing to keep the tube from moving around. I used a hacksaw blade bent ~30 degrees along its length to cut through the adhesive. After doing that, you should be able to push the tube out far enough to pull it out from the opposite end.

Good luck!

-Trevor

 

[Bratan]

Why disassemble it?!

Just buy a bare tube on ebay, that housing is in great shape!

-Trevor

Dude, you are genius! I basically just wanted to see how it works, but yeah getting a tube from eBay is a great idea! Hopefully I can find something cheap

 

[Trevor]

Dude, you are genius! I basically just wanted to see how it works, but yeah getting a tube from eBay is a great idea! Hopefully I can find something cheap

A tube and PSU will probably run ~$30 - but you may be able to find a guaranteed working set from someone here like daguin.

I'm pleased I rescued your HeNe from destruction...

-Trevor

 

[Bratan]

I'm pleased I rescued your HeNe from destruction...

-Trevor

Hehe, I never wanted to destroy it, was hoping to carefully open
BTW, that front bit I'm not sure it was originally part of the laser, I was able to remove it easily it's just held by tiny screws. It's purpose is to hold an attachment (some kind of lens or a prism). It turns beam into a line (like the one used in the laser levels). Do you know what it's called?

I assume f 1,2 is aperture...

 

[aryntha]

That's simply a line generator. What you described it as, is exactly what it is An attachment that goes on the end of the HeNe to project a line instead of a dot, for alignment/measurement/leveling purposes.

Powerful or not, that setup there is worth much more than $5.

I wouldn't try opening the head. It's usually set in there with epoxy or silicone, and you can't usually get them out. I'd just get a bare tube somewhere similar to the specs of your supply. (Which, by the way, for that tube, should be doing 1500-2100v @ 6.5mA)

The LGK-7621 is a multimode laser; somewhat unusual in HeNes. (Not advantageous, really. Just 'different' ) and it easily could be putting out 7mW or so.

 

[Bratan]

That's simply a line generator.

LOL awesome name :crackup:

 

[aryntha]

Yeah, kinda like how with laser guys, where the beam comes out, we like to call it an "aperture".

But really its just a hole.

 

[laser_freak]

I'm glad you decided not to disassemble it. It looks like a nice HeNe!

Yeah, kinda like how with laser guys, where the beam comes out, we like to call it an "aperture".

But really its just a hole.

I consider holes and apertures different. After all, you don't say that your nose has 2 apertures :crackup:

 

[qumefox]

Glad you didn't destroy that HeNe heh. And really, assuming you managed to get the tube out without destroying it,(which is unlikely, considering they're usually glued in when in cylindrical housings) all that you probably would have accomplished is going 'OOo! look at the pretty orange glow!' for maybe two seconds, then probably got against one of the leads poking at it and need to go change shorts. Most small HeNe's aren't fatally dangerous, at least unless you do something stupid like grab both end of a running tube with both hands or something.. But the experience still is far from pleasant I can assure you. I've only ever gotten 'bitten' by a laser once. And that was in the mid 90's on a small HeNe. Though i've gotten bitten by at least 5 TV's.. (Since, well.. I fix them for a living. And they were off, I had just got careless and forgot to discharge the CRT's). And I have to say. I remember the HeNe being a lot more painful than any of the tv's were heh. Guess it's the lack of current from the TV's. I think the HeNe was running around 2kv@5ma, while the CRT's probably had 30kv on them but virtually no current.

If you really want to know what's going on inside your HeNe, go here and read about it.

link: Sam's Laser FAQ - Preface, Introduction, What is a Laser?, Safety

THEN get a naked one to play with. I really think everyone should own at least one gas laser. Diodes are certainly convenient, but they're not nearly as interesting to look at while running with the covers off. You just need to know how they operate so you can be safe about playing with them.


And i'm not even going to comment on the whole aperture/hole thing....