Advice for first galvo/amplifier please

[JasonB]

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The thread above is pretty out of date; the main suggestion was to get the DT-40 pros...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 Many of the links posted are no longer valid...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

[DZ]

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The thread above is pretty out of date; the main suggestion was to get the DT-40 pros...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 Many of the links posted are no longer valid...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

Jason,

If you want the highest quality Chinese scanner, then DT-40's are the way to go. There are alternatives coming from China that are a good bit cheaper but you sacrifice quality.

The 20K scanners are nice for beams and such, however, depending on what you're plans are, you may kick yourself for not buying a set of scanners that can perform at the ILDA standard 30K.

You should check out ctlasers.com, which is run by gottaluvlasers here on PL. For a DAC, you should check out Pangolin's FB3 or for high end the QM2K.

Above all else, you should look into attending one of the Laser Enthusiast Meetings. There's one in Florida next weekend, and the big (70 attendees last year!) one in North Carolina in August.

[jooopy]

If planning the intense "beam-show"(more atmospheric than graphics on a wall) the DT-40wides are just a pinch higher $$ but they open up very nicely.

[JasonB]

Yes! it sounds like a good idea to invest in highest speed scanner according to budget; trouble is that it is difficult for a newcomer to understand the difference in performance of a 30K compared to 20K (let alone 50K).

So I'm thinking of going for the 30K right off the bat; just not sure how much we can trust the specifications.

I see a 30K ILDA for $165 with the following specs:
Scan speed:

±30° Optical: 18Kpps
±15° Optical: 25Kpps
±8° Optical: 31Kpps

or

30Kpps HightSpeed galvo scanner for laser lighting NEW
Speed: 30Kpps@±20°(ILDA30K Test Frame)
Deflection angle: max 70° optical (factory calibration @±20°)

Deflection angle
Operating voltage
Speed
20 optical deflection
+/-24V
>30.000pps
15 optical deflection
+/-24V
>32.000pps
10 optical deflection
+/-24V
>35.000pps
8 optical deflection
+/-24V
>40.000pps
5 optical deflection
+/-24V
>50.000pps

($179 + $40 shipping)

and finally the one from midwest-laser which looks like the poorest choice:

Maximum scan angle 40 degrees
• Frequency response: 1,700Hz ( 20K ILDA tuned )

So looks like me could use a push for the 30K as long it the performance is justified; my final goal over time IS to build a RGB projector. It will happen, I have surrendered that this awesome 'hobby' is in a fact a money pit that will pay fine dividends for quality equipment. (Pay x now, and find you want y, then pay x+y or just pay y?)

Feedback please!

Jason

[jooopy]

Name brands are usually what I see recommended in this dept. Quality yes but not by specs but rather by brand. Dragon Tiger or DT is well tried & trusted as a brand we know here. Deep pockets well then the Cambridge brand may be of help to you. DT40wides are well...what I personally enjoy. If I'm on that much of a budget I would really look into a DT30.

[JasonB]

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

[dnar]

Hi Jason, can you see the errors in the ILDA pattern? You need to reduce the scan speed OR make the image smaller.

The outer square corners should be clean and the center circle should not have tails and should be in the smaller box.

[White-Light]

Jason just one word of advice, sometimes buying the cheapest now isn't the best way forwards as others have said regarding the scanners. The problem is a small saving now can lead to a huge expensive further down the line when you get more serious and have to re-buy everything from scratch as you upgrade, rather than having to just upgrade just the odd component as you progress. If budget is very tight, you may have no other options but if there is any flexibility, then I'd say buy quality now, even budget quality brands, rather than the cheapest deals you can find on ebay or the web, as cheap now = expensive later.

[andyf97]

I would suggest new users save some money and buy the cheapest possible scanners while experimenting, then upgrade them later after experimenting.

This way they don't bust up more expensive scanners while figuring out what is what.

[JasonB]

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! ) 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/