An exercise in futility. More eBay crap.

[The_Doctor]

(Copied from my post on alt.lasers, just seeing what kind of feedback I get from showing this)...
Subject: An exercise in futility. More eBay crap.
From: Lostgallifreyan <no-one@nowhere.net>
Newsgroups: alt.lasers

http://tinyurl.com/ybnxrm

That's a dead listing on ebay. I killed it, I'm no longer trying to sell,
so please don't consider this as spam. It isn't.

Here's an ended listing: http://tinyurl.com/ymj99o

It shows what is being discussed in the questions on my dead listing, and
is why selling complete DPSS lasers on eBay is now a disgusting exercise in
futility.

Two years ago it was like new snow, everyone wanted a piece of the action.
Now it's rutted, pitted, pissed and shat in, and it's being trodden into
what's left of the clean stuff. If you look at the high-power new lasers,
few if any are getting any interest, and there's no effort anymore to try
to declare an honest set of specifications, and when anyone does try, it's
no use.

If I ripped out the IR filter and sold it as a 1500 mW beam laser I'd get a
flock of imbeciles craving to pay £500 or more, but as for selling it
honestly, which is the ONLY way I'd do it, it's utterly pointless.

Isn't it illegal to specify a safety label as vaguely as that in the second
listing I linked to? It looks to me as if someone had a load of those
printed out solely to defraud people.

[Spec]

Sucks being honest doesn't it?

I had the same problem about a year ago: I would get in a lot of lasers, add IR filters and measure output power with a lasercheck and scientech 365. Profit wasn't great but it was clean and easy.

Some other seller on ebay bought a few of them from the manufacturer and thought he must have got lucky because they were all producing 2 times what they were rated for and sold them as such.

I sent him a polite letter about it, he never responded... must have been drunk on all that pointer-jockey money.

A couple other people started doing the same thing and behold: it became impossible to sell anything.

I pretty much stick to the forum here because people know I'm honest and I dont have to deal with questions like "what is the frequency", "can it run on batteries", and the tepid "does this thing have a pot mod?"

I read through your q&a section on the ebay listing:

I had no idea that lambda pro units have higher output when running analog, sounds like they either messed up an opto-coupler *or* they were smart and found out that by increasing the drive strength they could reduce the amount of time needed to get back to full power.

Its strange... I like DPSS units but I'll be damned if I have played with one that has a good blanking system. Makes me wonder if its truly an afterthought for them.

[dream beamz]

Honestly my lambda UGA200 is one of my favorite and most stable lasers. Two years later and it has lost 10mw and is still producing 204mw

The UG series however, i disliked. I had two of them and one of them had to be sent back twice. I did get the free upgrade to the 200mw so lambda gets the thumbs up

[buffo]

Lostgallifreyan!

I saw your E-bay auction, and considered your opening price to be *very * reasonable for that 250 mw laser. In fact, in this thread here on PL I recommended your auction to a new member here that was looking for more power than he could get from his modded pointer.

To tell you the truth, I almost bid on your auction myself. However, I really didn't want to spend any more money right now. (I just upgraded Mamba 2004 to Mamba Black, and I've been saving up for the EasyLase USB DAC to go with it. Should be a bit of a step up from my Alphalite setup.) But your price was *very* tempting. Honestly, I expected your auction to shoot up way beyond your opening bid, and thus I stayed away so as not to be caught up in the frenzy.

You know, if you wanted to sell it, you might have been better off posting it here in the for sale area first. For one, people here know you, and are thus going to be more comfortable with the purchase. Two, there are some hobbyists here that have recently mentioned their desire to move up in power. Your laser would have been a nice step up for a lot of people, myself included.

I'm sorry that you had a rotten experience, but (saddly) that's the way it is with E-bay. And you're right, there are a lot of dishonest sellers that yank the IR filters on their DPSS units and try to pass them off as higher power units. There are some discussions here about members that have recently purchased power meters, only to discover that the high power lasers they bought are really only making 1/2 their rated power (or less) in the visible spectrum. That sucks...

Adam

PS: What ever happened to the Axicon project? You know, the one you mentioned in this post? Are you still working with Steve Roberts on this?

[The_Doctor]

Sadly, no axicons... I don't think that will happen. No-one's got the means to make them, and unless some can be made to exist, all bets are off. I'm thinking about another way to combine multiple beams, but I'll say nothing for now. I bet it's been thought of before, and if it were a goer, I think it would be common knowledge. A bit of optics modelling might show ways it cannot work. At least the axicon idea is obviously feasible.

I'd like to know how multiple beams are combined when based on polarising cubes. I might be missing something, but if all you have is those, laser diodes, and mirrors, the first pair make a beam of mixed polarisation. How this can be reduced to one plane for combining with a similarly treated beam to get a final mix from four diodes, I do not know, yet I've seen hints that it has been done. Any idea what I'm missing?

Re DB's comment on LambdaPro, curious, for me it's the other way round, I liked the older UG designs better, I have one that is usually well behaved, flickers a bit at times, but the 0.8 mm beam and tiny divergence and perfect round TEM00 are as good as anything I've seen, no laser I've had since has come close to it. Although I do have one early UGA (with a UG LPS-100 supply) that has the same narrow beam as the UG, and an output of around 150 mW (Was 200 mW nominally but it's been heavily used, was second hand when I got it). I'm hoping that Casix or other firm is making longer cavity composite crystals so we can get powers up to a watt out with a very narrow beam.

Lastly, while I'm no longer actively trying to sell, if anyone does want that eBay-listed laser of mine for £200 plus raw shipping costs, it's theirs. I need money for a project, and I'm going to have to sell my second (and last) Yamaha FS1R synthesizer, and a tiny ITX computer I just built, both of which I'd rather keep if I can. I have opened that laser to remove the IR filter so I could measure the combined output. I did this because I had to understand what was causing people to pay huge money for very modest lasers in some of the listings I've found or been shown. The filter is in place again, it was on a screw-in plate fixed with some kind of white UV-cure goop that sets very hard. That dodgy fan is trivial, I think anyone posting here would know there's no need to worry about that, and could easily replace it. None of these things have impacted on the actual laser output, but I can't be doing with the prebuilt lasers anymore, they don't excite me half as much as the prospect of building my own, which is what my project will be. Red at first, making money to try some green with.

[dream beamz]

my laser has the old power supply and operates on TTL only but the beam quality is fantastic with no flicker. Adam saw this laser in action. He can attest. Anyhow I will see if you still have this laser in a month and grab it from you if so

There are some chinese manufactures that sell their lasers with the visable output displayed even though they have no IR filters and they are still cheap

IE: Big dipper 50mw from them is $50 but total output power is around 300mw to include IR

[The_Doctor]

Nice. It will be first come first serve on this if I do get a buyer though, so I don't have to prolong things. eBay gives me a headache at times.

Interesting, you say your UGA also has the older supply. As far as I know, that's rare. Adrian Feudale said it didn't happen, that UGA's got LPS-300, and UG's got LPS-100. I've definitely GOT one here that says otherwise, and it seems you have too. The laser I'm wanting to sell hasn't got the same fine beam, it's the standard new UGA sort of a beam, good but not beautiful, at least to me. On the other hand, I've never seen it flicker after the first very few minutes after startup. If rock-solid stability is wanted over beam thin-ness, this laser will satisfy well enough, especially as the beam thickness is a good match for colour mixing with red diode output..

My old UG hasn't got an IR filter either. One thing I tried was measuring that during my test of the UGA 250, by holding the UGA's filter between the UG and a Lasercheck. It started out at around 150 mW! (Is meant to be 100 mW, nominally). Sadly, it falls to around 80 or less, erratically, within a few tens of minutes. If I can get a permanent IR filter for it, I'll monitor it and see if the TEC current can be tweaked to try to get stable full output. I think LambdaPro excelled themselves with that old UG, maybe they were still trying to prove themselves when they made it.

[steve-o]

Spec.
Did you used to be Specwhore? I really liked that name.

[Spec]

Spec.
Did you used to be Specwhore? I really liked that name.

Due to Arcane reasons only known to the masochistic PHPBB2 board programmers it came to pass that I *should* use two separate accounts for administrative functions.

I really have no idea why it *should* be setup that way other than some off the wall hack happening to one account where someone steals the session ID and unique auto-expiring cookie of the administrator *while* the administrator of the board happens to be logged in.

Mad, mad world these electrons live in.

[Banthai]

Spec ... the answer to the question should have been yes or no ..


BUT ... your reply has caused me to laugh ... and deposit a stream of red wine down my shirt

many thanks .... :lol: :lol: :lol:

all the best .... Karl