My first gas laser (HeNe)

Since it's my first post, I'll say hi.
I did have an account with a few dozen posts a while back, I read a lot more than posting, but I've just tried it and it seems to have expired and someone else is now using the username.

Aaanyway...
I've been tinkering with diode lasers for years but decided to get myself a nice HeNe gas laser from eBay. According to the seller it was assembled from a kit a while ago but it was the only one reasonably priced on eBay. It arrived this morning and worked fine out of the box, and by eye the 1-5mW claim seems correct (it appears quite a bit brighter than a 5mW ~680nm module). After a while a noticed a bit of a buzz coming from the unit so opened 'er up to have a poke about inside, and just to satisfy my need to have a good rummage.

Unfortunately, it appears to have been built into the box without servicing in mind, so I had to loosen the neon lamp to get the board out. When I re-assembled everything, I left the nut shorting out the lamp. I plugged it back in and *crack*, a flash and the glass fuse has tripped. Yes, I know I'm a dope but I'm not certain that's the only possible point of failure; in the pics below, you can see some of the parts are dangerously close to touching, and the fuse is about 0.5mm from being bypassed. I saw a flash but, not expecting it, I didn't see where it came from, although it was probably just the fuse.

The build quality is forgiveable IMHO considering it's a DIY unit (although I would have been much more careful with high voltage).

Besides replacing the fuse (I'll probably get a HRC one) is there anything else I should check? I'd like to get a proper potted PSU at some point but there are no obvious markings on the tube besides the sticker saying WK507.

I was hoping to get up some beamshots for my return post but NVM.

Hey Bluefusion. Didnt you screw a whole shit load of people here in the past? Maybe thats why you're not using your old account.

Nope, not me. Maybe he did but accusing new members of that isn't going to make you terribly popular IMO. If I was him, would I be daft enough to admit having an account previously?

Edit: After a quick search of the username, it appears he's from Australia. As you can see < I'm not. And assuming you're an admin you'll see my IP is a residential address in England.

HeNe said:

If I was him, would I be daft enough to admit having an account previously?

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He's done it before.

http://laserpointerforums.com/f39/nintendo-ds-lite-sale-41587.html#post543339

We'll see in the near future. You could have moved. You found out he lived in Australia pretty quick. It took me a while to find it, and I'm a pro.

If I'm wrong I'll apologize.

Your definition of pro maybe different to mine, but isn't using Google allowed? It wasn't terribly hard to find TBH, Google: site:laserpointerforums.com bluefusion
And the 4th link down: http://laserpointerforums.com/f63/bluefusion-resolution-solution-46499.html

So, you welcome all new members to the forum this way? Accusing them of being scammers with no slight indication, let alone proof, whatsoever? I thought CPF was bad. The 'elites' of some forums seem to forget everyone starts by making an account at some point, and assumes newbies to be some uneducated 12 year old.

Considering this is a laser forum, and the gas laser section, I thought some members would be interested?

one of the blue wires is possibly shorting to the case the one by the rust hole, check that insulation and make sure its not cracked or burned, while your at it use some wire ties to put some space between the wires and metal, high voltage has this way getting though insulation, ever touch a high tension cable on the back of a tv while its on, its got insulation but will still short to you and it hurts. I would go as far as replacing fuse but if you see an arc flash not a plasma tube flashing then you got a short. So check all your wires and move them away from ground.

Welcome to the wonderful world of gas lasers! They can be finicky (and not to mention expensive!) but they are incredibly fun and in the case of bare HeNe's look damned cool too.

It's likely just the fuse. About all you can do is replace it with the appropriate sized fuse and hope for the best. You could probably use a bit of electrical tape to cover it to keep it from shorting out. I had to do that in my Argon laser's head to keep it from shorting out and blowing up another PSU.

Thanks.
The outer case is plastic, but I guess you mean the transformer case? The fuse is blackened and the laser won't power on so it has definitely blown. I might strip everything from the case and put it into my own, re-do the wiring, with better spacing between the conductors and better electrical isolation; ATM all of the circuitry is out in the open as you can see.
It's a pity the tube has a metal sleeve, is it usually possible to remove this to expose the glass tube or am I likely to just break something?

I don't think that's removable. i wouldn't want to try to remove it either. You can get tubes that show a lot more of the plasma such as the green tube on the left in my avatar.

Not BlueFusion. BlueFusion lives in Australia still and doesn't have a HeNe

Things said:

Not BlueFusion. BlueFusion lives in Australia still and doesn't have a HeNe

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I humbly apologize. :beer:

I use spelling to find returning banned members. Your spelling of "Aaanyway" only hit one person out of the thousands here. Which was Bluefusion. 9 out of 10 times it works. Sorry.

No worries.
And ironically that's probably the first time I've said it on a forum!
After some searching it seems like he rightly gained a hostile reputation on the forums and it's understandable you're on the lookout for him, but IME they usually give themselves away after a few dozen posts. I've seen forum members gain infamy by ordering items from abroad then claiming it didn't arrive and filing a PP dispute every time.
It's quite easy to prove you are someone, but not so proving you're not!

I've desoldered the major components from the box and I'll pick up some fuses probably tomorrow on my way home. I might build this into an old metal case of some sort and properly ground it, for safety's sake, both electrical and because glass fuses have a tendency to explode when connected directly across 240v...

I've caught people with 0 posts in the past. :eg: People have a bad habit of checking out their old accounts.

Right, so after stripping it down I noticed it was indeed (or at least very probably) caused by that nut shorting the neon lamp. I originally thought it was powered from a transformer secondary, but it's connected straight to mains so it was basically shorting mains and the fuse did its job.

Anyway, I stripped out the neon lamp and switch to reduce the risk of shorting anything, I might add an in-line lamp switch instead.

For now, I'm using a 1A ceramic fuse (possibly HRC) from a shaver adapter but I'll pick up some more lower current HRC fuses eventually. It's working fine again. Even when it goes dark I don't think beamshots are going to be possible without fog, but I can always get some pics of the nice round dot.

Edit: Quick photo

Much tidier,

Edit 2: Oh I forgot to ask, do you have any tips regarding the use/care of these lasers? I'm aware they're meant to be used occasionally to keep them in good condition, but is there anything else e.g. leave for x minutes before turning off/on or something?

I'll let the resident experts chime in here but I've let my HeNe lasers run for a good hour or so before with no ill effects. I don't have a place to keep my HeNe's set up all the time so when they're put away I try to get them out every month or so and fire them up to keep the tube pressure healthy although with modern hard sealed tubes tube pressure shouldn't be an issue like it is with say Argon lasers. Just be careful when messing with the "guts" of the laser. That small tube probably runs on about 1200-1500VDC at around 3.5mA. While shouldn't hurt you (the average static electricity shock you feel is around 10KVDC IIRC) it can still hurt like hell causing you to drop the laser.

HeNe's are quite different from argons, the gas pressure for example is roughly the same during it's lifetime without any gas fill system needed. HeNe's also can be left sitting still for years and still work fine. Just read Sam's laser faq for the details.