need help planning my projector

[yaddatrance]

Sorry...

we're going to pretend that the battery is the dac. So you're tie the battery to the signal to check if the beam is stable when it isn't centered.

If you post pics of the circle I might be able to tell if it's the dac or if you need to get the scanhead looked at.

[jkaiser3000]

I thought that's what you meant, wanted to be sure though .

So, I did just that. Placed a AA battery across the input terminals on each scanamp and the laser moved smoothly in each imaginable direction. Applying the voltage to the X marked amp moved the laser up and down, and the Y marked amp moved the laser left and right. The movement is reversed because my laser is hitting the top mirror first (Y marked galvo).

On another note, I tried the circle again. After some tinkering with the pot, I'm pretty sure it's getting some noise into the system, as moving it made the laser move somewhat randomly and the galvos made a noise too. So, I'll try that next, with the pot out of the equation.

Here's the video of the supposed circle

[yaddatrance]

The next thing to try is to swap the x and y axis cables while running the circle... see if the problem swaps axis.

I also had a thought, is it easy for you run the laser seperately, it's possible you're getting noise from the return on the color line.

[jkaiser3000]

actually, on the last couple of tests the laser wasn't hooked to the blanking pins. I'll swap axis now and see what happens

Edit: just tested swapping the axis, and here's the result. The first part of the video is with all axis as they should be connected. The second part is with X&Y swapped on the amp's input. The videos were not taken consecutively, and the camera was a bit tilted and displaced with respect to each other, hence the apparent tilting on the second part.

By what I can see, I'd say one of the amps has a higher gain for the galvo than the other. That'd explain the big difference in size when axes are swapped. Well, that's a wild guess on my part. Also, both tests were still with the pot connected, I need to find a way of connecting the wires securely, yet easy to remove for testing purposes. That will come tomorrow, I promise . I really feel the wiring in the pot is a bit loose or something, and it's getting some noise into the system. But, that won't explain the size diference :roll: .

[jkaiser3000]

Guys, I appreciate your help, but there's nothing else to do now as these things are officially dead. I tried the galvos again, to test some other figures, like a square. For this, I connected the galvos to the amps and the easylase to the amp as well, then powered the laser and aligned it with the mirrors, powered the amps and the mirrors centered well. Finally, powered the easylase and the galvos sounded stranger than ever before, so I disconnected it immediately.

Upon further examination of the galvos, I saw some smoke billowing out through the shaft on the upper mirror. By this time everything was unplugged from the power supply too. I disconnected everything from everything else and then tried to move the mirror in question, very gently, with my finger. I know I shouldn't do that, but it's supposed to move somewhat freely when not powered, right?. Well, it doesn't anymore. I guess it overloaded and melted the wires inside the casing, which got glued to the magnets.

To tell you the truth, I'm mad (at myself) and frustrated. I was really looking forward to writing my name on the wall with my laser :roll:

Edit, talked to spec and he's agreed to take everything in for some serious, high quality testing.

[Spec]

Shoot me a PM, we will get this fixed.

Do you have Skype?

[yaddatrance]

That's too bad, I hate it when the magic smoke escapes. Takes a lot of work to cram that smoke back in...

Don't give up hope, I'll also make you some ILDA files to test the board with a simple voltmeter. (I've been
assuming up to this point that you don't have access to a scope)

[jkaiser3000]

You assumed right . I don't have access to a scope, just a multimeter. At this point, I'm inclined to think the problem lies in the board, not the amps or galvos, although the galvos are the ones that suffered.

We'll see :roll:

[Banthai]

Yadda Wrote
That's too bad, I hate it when the magic smoke escapes. Takes a lot of work to cram that smoke back in...

Think on the positive side ......

No need to buy a a fog machine ..... boom tish

but realisticaly ...... we have all done that to some degree and you learn by mistake ( yes expensive ones ) but you learn.


all the best .... Karl