I'm a student, very new to this, and need help. Want to build my first scanner.

[dsli_jon]

Hey Mr B -

..Holy -- that is -- so freaking awesome!!!!!
You are _not_ sending that to me. There's no way, that's too freaking sweet.
JUST NO WAY. NO, NO WAY.
Really???

(..said in best William-Shatner voice: ..Relax, Maaan!....it's...just a HeNe!.. I mean, it's not like I'm sending you a *Pony* or anything.. Sorry, corny joke, nothing to do with you... Seriously, glad I could 'make yer Sunday'...

Thank you so, so, so, so, so much!! I do not deserve this much kindness.

Oh yes you do... see, these are the kind of 'rewards' that one can realize when, oh, just say for example, one gets good / helpful advice, etc, etc.. and then does NOT-go and start 'shooting 40 Watts of green around ones' backyard' filled with innocent / unawares partygoers, etc, etc - as a first-project... Again, dumb joke, nothing to do with you... Suffice to-say, it's an 'entertaining back-story', for another-time...

I promise I'm going to do my darnedest...

Hey, dude, I'm just-glad to not have to *argue* with you, as-to why it might 'not-be such a good-idea' to go making your very-first pet-project trying to 'outline outdoor-buildings on your campus' with a multi-Watt Chijector.. < insert record-scratch snd-fx > Very-good to see you choosing to 'take the high-road', and learning to 'walk'- before you jump into the Top-Fueler..

Anyhoo, be-sure and note the 'HeNe safety-reminders' sheet, found in the box, when ya get it.. and.. it's about *high-voltage* / Alden-connectors, and such.. not so-much about 'not pointing the thing straight in yer cat's eyes', etc.. Not too-worried about that... Well, I think I've just-about used-up my allotment of smileys for the nite, already so, will let ya know when yer little 'box-o-photons' sails, and will be in touch, I am sure, later-on..

cheers..
j

[norty303]

Well, I think I've just-about used-up my allotment of smileys for the nite

Yours, and everyone elses.

There is a world shortage of smileys, punctuation and formatting options because of you Jon (not even enough for an exclamation mark on the end there but I found a couple of brackets in the gutter not even matched ones though]

[dsli_jon]

Yours, and everyone elses.

..but today's a new-day..

There is a world shortage of smileys, punctuation and formatting options because of you Jon..

..well, what can I say.. Oh, I know..

http://www.youtube.com/watch?v=D6uoleKeDe4 Gotcha!...

cheers..
j

[echelon]

Hey, does anyone know where the current IRC network is, or if it's still maintained at all? I tried connecting to irc.36hz.net:6667, but it wouldn't connect. Maybe it's just this coffee shop connection (but I could join freenode, so...)

[swamidog]

it's working for me. there's a bunch of us in there now. we're trying to goad sugeek into bringing us lattes.

6667 may be blocked at your coffee shop. try 6697 and channel #photonlexicon (ssl irc).

Hey, does anyone know where the current IRC network is, or if it's still maintained at all? I tried connecting to irc.36hz.net:6667, but it wouldn't connect. Maybe it's just this coffee shop connection (but I could join freenode, so...)

[echelon]

I'm not sure what the issue is. I'm able to get into FreeNode just fine, but I can't connect to either of irc.36hz.net's IRC ports. I think I'll just have to try from home.

I do know that the bookstore is blocking SSH. I can't push to github either. Very strange; I may have to find another venue.

[echelon]

Sorry to double post, but I figured my questions/updates were merits for bumping the thread.

I got the HeNe from Jon today! It's really awesome, I'll post pictures soon.

I've been hanging out in #pl on 36hz, and I've gotten a lot of initial advice. I'm definitely going to buy the EtherDream DAC, without question, since I'm much more of a software person. I'm settled as far as the DAC is concerned--this is the interface I want to program for.

A few people (LaserCo, et al.) suggested that I buy a Reke 500rgb and upgrade the internal components as I go. It has ILDA input which I think means I could use it with the EtherDream DAC directly. A primary reason for this suggestion is that I don't think I can build a custom case for a completely custom build. I don't have the tools, and I won't have regular/everyday access to my university's engineering department labs. The faster I can get to writing software, the better.

If I go with the Reke, I'm worried about two things -- the KPPS is really low, and the lasers aren't very powerful. I doubt I could display on a building like I want to. Could I simply buy new lasers, galvos, and PSU and put them in the case? Would that negate the entire purpose for buying the Reke as a starting unit? Are there any cases that come pre-drilled for building projectors? That might be better and let me skip the Reke entirely.

So, if I do the Reke build:

• Reke 500rgb
• Ether Dream DAC
• ILDA connector
• Potentially replacement RGB lasers (more power)
• Potentially faster galvos
• Potentially need a better power supply if I replace the built-in equipment

If I start from scratch:

• Durable case that can withstand abuse (pre-drilled)
• Flight case
• Power supply
• Fan
• R, G, B lasers
• Fast galvos
• Etherdream DAC
• ILDA connectors
• Lots of misc. supplies...

Is there maybe an intermediate? A prebuilt projector that's perhaps a step above the Reke? Alternatively, maybe I can buy a projector from someone on the forums that might match my specs? (Or have someone here build one for me for a fee?)

I do like the idea of gutting the Reke. I just don't want to waste too much of the summer figuring things out. I want to jump right into writing software.

Edit: Better link for the Reke specs.

[Bradfo69]

Phew... I started reading this thread not long ago and then came back to revisit tonight. I'll throw in my .02 for what it's worth. Couple of points, and this may have been mentioned while you were in IRC but, outdoors on a building with satisfactory results I don't think is anywhere close to your budget. MAYBE with just a green. I have a 3 watt RGB that I have taken outside at work at night and projected on the building on the other side of the parking lot - perhaps 200 feet or so. And while I could see it and it was "ok", it wouldn't be the kind of thing that would excite people enough to give me a grant at a university, and this projector was a little under $10,000. Sorry... facts is facts. MAYBE a used 1 to 1.5 watt green could be made into a projector with 30k galvos and all the bits and pieces within your budget but, you've also got the DAC to consider. Not trying to rain on your parade. It's just I'm afraid what you want to do is going to end up prohibitively more expensive than what you have to work with.

The other thought is about the REKE. I suspect one of the reasons it has been suggested, is the quality you get for such an incredibly low price. For a chinese projector, it is what it is and, is nicer that most. And $209 for a half watt RGB is unheard of. It's a really nice starter "git yer feet wet" projector. I've seen it in person. I have two on the way. I know the difference between legal and not legal, and quality versus some of the really crappy stuff coming out of china and, this particular unit is really worth a look. Sure, you could pick it apart in time but, the problem will be it's a small case and your moves up in power will take more room. HOWEVER... you want to begin writing software and spending more time working on that. The REKE is going to give you the opportunity to see the fruits of your labor at the lowest possible price point and still be a decent little unit for your basement or den for not much more than a decent concert ticket or a good nights bar tab.

Keep asking questions... keep reading... keep us updated. And, include SELEM on your radar if at all possible.

[echelon]

Thanks for the input! Sorry that it's so much to read. I'd rather read the truth than waste time with unrealistic expectations. I should have figured that it would take a lot of wattage/$$$$ for an RGB setup to project on a building.

As you said, green diode lasers might be able to pull it off within budget. I do know that I've seen such lasers used to project maybe a quarter of a mile before. I'm not sure what the wattage of this kind of laser is, but it was handheld and powered by AA batteries or something.

Why is it that green lasers alone have this property? Wavelength is inversely proportional to power, so why is it that only green lasers are so visible at a given wattage? You'd think that blue lasers would be the most vibrant and visible. Is it a property unrelated to wavelength/frequency? It has to be.

I'll order the EtherDream DAC and the REKE to get started (I can use these together, right?), but I still want to build something with a green laser and high KKPS/scan angle so I can scale to buildings. If nothing else, it might be good to work on two different laser projectors so that my software can handle a variety of different parameters -- KPPS, scanning angles, and so forth.

Also, the REKE lasers use TTL logic, which is fine for the price. If I build a monochromatic green projector, would it be more expensive to do analog so I can modulate the intensity? That might make up for it being a single color.

[j4cbo]

Why is it that green lasers alone have this property? Wavelength is inversely proportional to power, so why is it that only green lasers are so visible at a given wattage? You'd think that blue lasers would be the most vibrant and visible. Is it a property unrelated to wavelength/frequency? It has to be.

I think the "inversely proportional" that you're thinking of is the relationship between wavelength, power, and amplitude in things like sound waves. The visibility of light depends on the eyes's sensitivity, which looks vaguely bell-curve-y, most visibility per watt near the middle of the spectrum and less so towards the ends. Take a look at:
http://en.wikipedia.org/wiki/Color_v...lor_perception
http://en.wikipedia.org/wiki/Luminosity_function

I'll order the EtherDream DAC and the REKE to get started (I can use these together, right?), but I still want to build something with a green laser and high KKPS/scan angle so I can scale to buildings. If nothing else, it might be good to work on two different laser projectors so that my software can handle a variety of different parameters -- KPPS, scanning angles, and so forth.

Also, the REKE lasers use TTL logic, which is fine for the price. If I build a monochromatic green projector, would it be more expensive to do analog so I can modulate the intensity? That might make up for it being a single color.

The Ether Dream should work fine with that projector. Hope you like it.

Analog modulation tends to be standard with nicer lasers; I wouldn't expect a big price difference.