Advice for first galvo/amplifier please
Hi All,
Hey I'm considering purchasing a 20 kHz scanner/amplifier from midwest laser and did some research on this forum.
http://www.photonlexicon.com/forums/...=midwest+laser
The thread above is pretty out of date; the main suggestion was to get the DT-40 pros... Are there any other alternatives nowadays ?
It has been discussed, but the link for the scanner is http://www.midwest-laser.com/html/co...aser_show.html
They claim Maximum scan angle 40 degrees • Frequency response: 1,700Hz ( 20K ILDA tuned )
Looking for some suggestions on WHERE to buy and what to buy. Just the scanner/amplifer... no DAC, no enclosure, etc. Many of the links posted are no longer valid...
Thanks everyone, appreciate your knowledge and time!
Jason
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Update - galvo purchase with ILDA pattern
Hi, thought I'd give a little update here in case it helps out any other novices...
I'm using a USB soundcard and Jame's correction amp design which is currently breadboarded.
Here is an image and an ILDA pattern for 20kpps phenix galvos. Not professional quality but good enough for me. Note I'm projecting onto folding doors that are not flat, take that into consideration.
100 mL green from O-like is a nice laser but honestly sort of hurts my eyes when observing graphics, it is more suited for beams. The red is 'easier on the eyes' for graphics.
I've learned that more power is not necessarily better for amateurs! Depends on what you want to do. And get analog if its in your budget. More for safety (lower power during alingment) than the endless color possibilites.
The idea was to build up the projector on plexiglass so that it would be easier to transfer the hole pattern to an aluminum base. BAD idea! While it is easier to mark holes since you can see through it the material is way to flexible, even for a prototype.
Seeing that I can't seem to align dicros, even with my 1 watt blue 445nM (dicros and blue not shown) that has the same beam height as the green I'm thinking beam alignment is not my thing. (Flame me if you must for this next statement) The Reke 500 RGB projector is looking attractive. Perhaps using the REKE lasers and case then swapping out the galvo might be a good route ..... Two reds combined with PBS along with green and blue already aligned in a Reke doesn't sound bad at this point!
By the way, if you want a free 12 Watt Argon gasser PM me. Its in the buy/sell forum. Maybe you could teach my how to align these beams on this projector build when you pick up the gas monster... (I have safety glasses for the low power solid state stuff). Even trying near field, far field, its still pretty tricky with cheap dicro mounts....
And no, I did not try to combine the red with the green on this prototype using the silly putty mount! ;)
... Just an honest amateur sharing his (not so impressive) build....
-Jason
RGB Projector Build Update (Pictures! Learned stuff! Mistakes!)
Hi All,
Well I was so happy when I first saw beams were combined that I had to update this project's progress! Yes, it is just another RGB projector build but remember the excitement when you first built one? I was just reading a thread that was saying how some of the forum posts are losing some of its innovation, etc. and that the seasoned members don't even post these builds anymore because 'its nothing special'. Well I bet your first one was! :o) The 'beam table' was just transferred from a temporary plexiglass sheet to aluminum. Plexiglass: BAD for alignment, GOOD for making a drilling/mounting template. Mirror mounts are the MM1s from laserman532. Buffo provided motivation, beam alignment help, and pointed me to laserman532 for the MM1s in a very kind, detailed, helpful PM.
Unfortunately I ordered the optics from O-like, the reflect red/penetrate green is pretty good, but the reflect blue/penetrate green is poor quality.
So I found a nice dicro from C.T. lasers and gave Marc a quick call to discuss the optics. He was very helpful and now the projector is looking forward to a cleaner blue/green combine. Can't wait to get that installed.
I learned A LOT from this forum and my mistakes during the build. The first error was my approach to purchase 'as much' power as the budget allowed without considering white balance. So this projector has a horrible power mix for colors but the beams and graphics are still impressive! It has 100 mW 532 nm, 150 mW 655, and 1 Watt (oops!) of 450.
Scanner is 20kpps, DAC is soundcard and correction amps are still mostly breadboarded. Lasers are TTL (mistake, should have gone analog from start but that costs much more $$$$. But now the worst that can happen is the TTLs could move to satellites if I build another).
This projector 'on a budget' still costs around a thousand dollars as it sits now. Knowing what I know now if I was to start over the cost could be almost cut in half, but the journey and making mistakes are half the fun!
I carefully considered the feedback 'buy high quality now, or pay more later' which is sort of like "rush the job because you have no time, but then you have time to do it twice". The flip side was the advice 'buy cheap now because you are learning' which also makes sense because bad mistakes could be less costly. So I basically purchased what I could afford at any specfic point in the project.
Here are a couple pics (Thanks WhiteLight for turning me on to imageshack).
We all suffer from the same sickness LOL
http://imageshack.us/g/1/9977363/
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'Housed' my first RGB projector
Attachment 36856Attachment 36857
Well here are a couple pictures of my new baby. What an interesting adventure this build was, took a couple years working on it 'on and off'. If I could start over from scratch knowing what I know now here would be the changes:
- Purchase higher PPS scanners (This is 20K, 30 or 40 would open up the world of graphics quite a bit, but 20K *does* do some impressive animation for a hobby projector). Galvos/amps are Phenix Electronics from China.
- Go Analog instead of TTL; I would gladly have lower power and analog lasers instead of 'higher' power TTL
- Purchase ALL my optics from Marc at CT Lasers! The dicro on the right is from CT Lasers, it is efficient and has excellent quality. The one on the left is from (embarrased) o-like in China.
- Layout the hole patterns in CAD, if you look carefully you can see my primary beam (green) has quite an angle to it with respect to the scanner. The center laser (blue) has a wicked angle as well, this should all be perpendicular. But I gotta say I had a hell of a time getting this thing aligned so I'm just happy it works! Notice the paper shims there? LOL
- It would have been much easier to use a steering mirror for the primary laser rather than mounting it like I did shooting straight into the scanner.
- Find some nice laser drivers such as flexmod, right now I don't know where to purchase analog drivers for diodes <1 Watt.
I am glad however that I sorta went 'cheap' because there is so much to learn. Burned out the red once due to a reflected beam from another laser going into the aperature during alignment. So it was nice that was not a several hundred dollar mistake.
So here is a huge THANK YOU to the community! I'll have to start working on the wife and plant the seed to attend a LEM in the near future, I'd really like to meet some like-minded folks in person.
Still working on getting the blue laser blanking circuit working correctly, will post some scan images when that is complete.
-Jason
