need help planning my projector

[jkaiser3000]

Hi everyone, as you can guess from the subject, I'm currently in the planning stages for my projector. At first it'll be a very simple one, just the glavos and a green laser. So, my first question is, does it really matter what mirror the laser hits first?. That is, if the laser hits the top mirror, labeled as the Y axis on my glavos, won't the image be rotated 90º? is it possible to "derotate" the image with software?, or am I drowning in a glass of water?

Thanks for your help

[allthatwhichis]

I though I read somewhere to come in from the left. Not sure where. I want to say it was off the scanpro maual but could be wrong. I read a lil too much. I think that'll always be the X galvo on top. I know popelscan has a swap x/y and invert for each. If popelscan's got it I would think most other software would also.

[jkaiser3000]

Ok, thanks. I think the X axis will always be the first mirror to be hit by tha laser, regardles where it's located. My galvos are labeled as X-027 and Y-027, as well as the amps. I think that's meant to let me, an ignorant person on this matter, know which galvo to connect to which amp.

Anyway, this brings me to another silly question, don't I need to connect the amps to the DAC? How else would the galvos know where to point at, right? Well, the real question is, where are the amps connected to the easylase?, and what connector on the amps is used for that?. I only see 3 connectors on the amps, one for the power supply, another for the galvos, and one that has 2 pins labeled GND and IN+. Would that last one be the one?

[allthatwhichis]

Yes, the set of DT40s I got from cruch came with a knob that took both galvo wires and attinuated them. A gain knob. IT takes the x- and x+, and y-, and y+, and combines the two -'s and a three prong plug comes out to attach to the DAC. I'll see if I can grab some pictures. But yes the GND and IN+ are your amp/galvos x/y- and x/y+ that attach to the DAC.

[cruch]

Thats true!
Have you tested them yet??

[allthatwhichis]

YEa, you didn't see the results in my "My first projector" thread. Thery are drawing way off. That's why I was waiting to speak with Rick when he gets back from vacation. I did notice though, the numbers don't match up on the amps and scanners. X is 35 on both, but the other amp says Y35 and the other galvo says Y34. :? Will this cause a problem?

[jkaiser3000]

I believe those numbers mean the amps and galvos are matched. If the numbers on yours aren't the same, then perhaps the galvos are not matched. That means you need to recallibrate them with the ilda test pattern.

That's a wild guess on my part, remember, I have no experience on this, at all

At least mine match, so I'm hoping I don't need to tune the amps :roll:

ohh, and where exactly on the easylase are the amps connected?, to the ilda connector?

[buffo]

ohh, and where exactly on the easylase are the amps connected?, to the ilda connector?

Exactly. The ILDA connector is a standard 25-pin connector (identical to a parallel port, just wired differently) that nearly every DAC supports. That way you can build a projector that also has an ILDA port and plug *ANY* DAC into it and it will function correctly.

Adam

[jkaiser3000]

Ok, now I have that kinda figured out.

My next question, what's a better way to connect the galvos to the easylase?. Single ended or symetrical?, Which is easier? I was re-reading this thread, where Astroguy was trying to hook up the dt-40 to the easylase. I think he ended up doing it single ended, but can it be don symmetrically?, would it be easier and safer?. Do I really need the 4k7 resistors?, I was left with the impression that those were not really needed, but I don't mind soldering them (I'm sure I can find some SMD resistors around, I have a lot of junklying around ).

And, one last question, for the moment. I was reading the easylase manual, and some pics on the thread I mentioned before. What are pins 3 and 16 for? It says intensity, but for what?, each laser has its own TTL signal on pins 5-7 and 18-20.

I guess that's it for the moment

Sorry to be such a pain

[Spec]

Ok, now I have that kinda figured out.

My next question, what's a better way to connect the galvos to the easylase?. Single ended or symetrical?, Which is easier? I was re-reading this thread, where Astroguy was trying to hook up the dt-40 to the easylase. I think he ended up doing it single ended, but can it be don symmetrically?, would it be easier and safer?. Do I really need the 4k7 resistors?, I was left with the impression that those were not really needed, but I don't mind soldering them (I'm sure I can find some SMD resistors around, I have a lot of junklying around ).

And, one last question, for the moment. I was reading the easylase manual, and some pics on the thread I mentioned before. What are pins 3 and 16 for? It says intensity, but for what?, each laser has its own TTL signal on pins 5-7 and 18-20.

I guess that's it for the moment

Sorry to be such a pain

You have dt40's. The input is singled ended. You, and I cant stress this enough *may or may not* need a 4k resistor tied to ground to make it work... I never had to with alphalite or pangolin, easylase might not have internal limiting, dont know as I never played with it. What I do when setting up a rig is have isolated grounds for digital and analog, it just makes sense to me and can offer similar signal stability on par with bipolar inputs over the short runs usually found in a projector case.

Bipolar input is primarily used for signal stability over long distances. Say you need the DAC down here on the floor by your controlling computer while the laser and galvo's are 10 feet up to clear CDRH regulations.

Pair 3/16 is used as a "modulate everything" signal. Good enough for single color projectors when projecting full color frames. You will end up with "just the channel your tied to" otherwise.

Guess it could be used for a EM flag to kill output when using gas lasers that are inherently unmodulatable, but Pair 13/25 would be better as most software knows when to signal high/low to those leads.