Where Can I Get One Of These?

[Lance]

I came across this component recently:

I don't know what it's from. It's just a pair of mirrors set 45 degrees apart from each other. It turns light 90 degrees, and allows x/y position control. I tried messing with it today using a little 5mW laser pointer and a pair of function generators. I was able to get some neat stuff done with it. I was wondering if anyone has any idea what sort of machine this part would have come from, and where I could get one.

I've tried searching around ebay, and the commercial ones I've seen go for several thousand dollars (but they are much fancier). Does anyone know what sort of equipment would have this sort of device in it? I'd like to get one of my own. My ultimate goal is to try and draw things using a laser.

[Psi]

They look a little different to the ones i'm used to seeing, but they're called galvos.

Used in laser projectors, like you might see at a concert.

Cheapest place i know of to get them is on ebay.
But if you ask around on laser forums they often know who has the best value for money.
Ya can even get kits with the galvos, controller pcb and software.

[Lance]

I tried looking on eBay, and found nothing like that device. The stuff I found was set up differently. They're just spinning mirrors on motors, as opposed to what's on the device I found.

Do you have any links to laser forums? I'd like something pretty simple, like what's above so I can try writing the software myself.

[elCap]

Some links
* http://elm-chan.org/works/vlp/report_e.html (if you want to build yourself)
* http://www.laserfx.com/
* http://www.cambridgetechnology.com/index.html

For a laser projector you want very fast galvos using powerful amp and feedback to be able to draw nice pictures.

[mikeselectricstuff]

The  old Philips laservision videodisc players had an assembly very similar to that, although  all the ones I've seen had rectangular mirrors.

[Lance]

Some links
* http://elm-chan.org/works/vlp/report_e.html (if you want to build yourself)
* http://www.laserfx.com/
* http://www.cambridgetechnology.com/index.html

For a laser projector you want very fast galvos using powerful amp and feedback to be able to draw nice pictures.

Those look pretty handy! That first link is especially interesting.

The  old Philips laservision videodisc players had an assembly very similar to that, although  all the ones I've seen had rectangular mirrors.

I see, I haven't heard of laservision disks before. Can you suggest any other hardware that would have of those inside? Something that would be relatively easy to get.

[Psi]

Do you have any links to laser forums?

http://www.photonlexicon.com/forums/forum.php

[Fraser]

Retail Point of sale terminals (POS) can incorporate similar units in the more sophisticated laser barcode scanners. X & Y co-ordinates are scanned using one laser and these devices.

[Psi]

I tried looking on eBay, and found nothing like that device. The stuff I found was set up differently. They're just spinning mirrors on motors, as opposed to what's on the device I found.

if you've never seen galvos before its easy to think they're motors from their apperence.
eg..


but they're not motors, they can only rotate a fraction of a full rotation in either direction. They're designed to move extremely quickly from one angle to another.

[Lance]

I tried looking on eBay, and found nothing like that device. The stuff I found was set up differently. They're just spinning mirrors on motors, as opposed to what's on the device I found.

if you've never seen galvos before its easy to think they're motors from their apperence.
eg..


but they're not motors, they can only rotate a fraction of a full rotation in either direction. They're designed to move extremely quickly from one angle to another.

I see. I'll look around and see what I can find. Thanks for the link to that forum.

I was talking to someone earlier about these systems. From what he said a very fancy feedback system is needed to make it all work. For something like the part I posted  would you get feedback from the galvanometer? Or is that sort of setup only needed in high end applications?