Guess I need to tune

[fluff]

I can play "smoke on the water" on a pair of 6800's


fluff

[Banthai]

Hahahah .... mark you should be able to play "Bohemian Rhapsody" on a pair of 6210s then

karl

[carmangary]

Does anyone remember the old Commodore 64s? There used to be a program that would play songs by vibrating its disk drive head. I'm not sure how good it was for the disk drive but it was still pretty cool.

[norty303]

If you are getting noises then i'd be fairly sure you're overdriving them. The rounded corners on a lot of your patterns are a give away too. I've just finished tuning some scaneco15's and they can produce nice sharp corners and accurate images, albeit flickering at 12k. If i overdrive them by upping the scan rate or increasing the image size too far then the images start to deform and go all rounded, just like yours are, and the galvos start to make fluttering noises.

[laserLips]

Im running them at 100% scan rate, so they shoudl be able to take this.

I've made the scan angle as small as I can possible get without the image being a dot and no matter what angle it is, they still curve at the corners. The only thing that makes a difference is the scan rate. If I put this to about 30% (LOTS and lots OF FLICKER) then the image displays correctly.

I'll have another go at displaying the ILDA test pattern. Perhaps I'm being to presumptiouse and tryign to scan complicated graphics..sitting back and watching a beam show with these is still better then se.... chocolate.
Shoudl 20K scanners be able to display the pattern @100% without flicker and distortion?..(disregarding tunning of course)

Graham

[buffo]

Graham;

I'm not sure what you mean when you say you're displaying them at 100% scan rate. If you're running the FB3, I think you should be able to select the scan rate in points per second rather than as a percentage. You don't want to run your scanners any faster than they're rated for, so in your case you should be set at 20Kpps. (If you are set at 100%, that could mean that you're sending data at the max rate that the FB3 is capable of, which is a lot faster than 20Kpps!)

If you are getting rounded corners, that *could* be a tuning issue, but more likely it's because you're pushing the scanners to hard (as in, the scan ANGLE is too wide) or too fast (as in, the scan SPEED is too high). My money is on the last option (scanning too fast).

As to your second question - A set of 20Kpps scanners should still be able to display the ilda test pattern correctly (that is, no distortion, sharp corners, straight lines, and the circle just touching the square), but the image *WILL* be flickering! 20Kpps is not fast enough to scan a complex pattern like that without showing some flicker. In fact, at 20Kpps, *many* graphic images will exhibit some flicker. You are never going to get rid of the flicker so long as you are scanning at 20Kpps. (Even at 30Kpps you can get some flicker on complex images.)

So don't worry about the flicker. You can't do anything about it. But you can do something about the rounded corners and wavey lines in the test pattern, assuming you are running within the limits of the scanners.

Adam

[laserLips]

Adam,
The Fb3 in LiveQ has two methods of speed control. The PPS is one, which is set to 20k and the second, a scroll bar on the front panel, which can be set from 0% right through to 200%. I set this to 100, but when I want to get rid of the flicker I put this to 200, obvoiulsy the images get worse....but for beams, you cant tell.
But as I said before, no matter what my angle is, its never makes any difference.
The angle is controled using the 'focus' scroll bar. The is in effect Zoom. If i Zoom all the way in so the image is very small, this has no effect, none that I can see. The corners are still very much rounded.

Thanks
graham

[buffo]

Ok, try this: Set the scan speed at 20Kpps, set the "focus" such that the scanned image is 14 cm tall when you are projecting at a distance of 1 meter. (This equals 8 degrees of optical scanning angle.)

Now adjust the percent speed slider DOWN from 100% and see if you can get the rounded corners to go away. If you get down below 50% speed and the rounded corners are still present, then I'd say you need to re-tune.

On the other hand, if you get the speed down to around 70-80% and the image quality gets sharper, then that speed control is over-riding your 20Kpps speed setting. In this case we'll need to do some more investigation before you start playing with your tuning.

Bottom line: Running your scanners at greater than 20Kpps (by pushing that slider up to 200% like you mentioned) is a BAD IDEA. Your scanners are not designed for that, and you can kill them doing it.

Adam

[Things]

Ive noticed that if I turn up the scan angle (Using DMX) on my X galvo, it gets VERY noisy. I have had a few probs with the galvo's, and it could just be something bumped. I guess I will take a look at it once I get my new laser module. I dont think they would make the DMX board overload the scanners

[buffo]

I don't think they would make the DMX board overload the scanners

That all depends on how the scanners were tuned. It doesn't have anything to do with the DMX board. You can most certainly damage the scanners if you over drive them.

Here's an easy test. Load the ILDA test pattern and set your scan *SIZE* to a very small setting. Now increase the size until you get 8 degrees of optical scan angle. (That is, the pattern width divided by the distance from the scanners to the wall equals about .14)

Now, what is your size setting at? If it's down around 15% or so, then cranking it up to 100% with the ILDA test pattern still being displayed will hammer the shit out of your galvos. You'll know it too, because they'll start to make all kinds of noises. At the very least, you should trip the polyswitch on the amp (assuming it's so equipped). Worst case, you could ruin them. In this case you'll need to reduce the input gain on your amps, or else be sure to reduce your scan speed whenever you load complex patterns.

On the other hand, if the size setting is already at 50% or greater before you get to 8 degrees of optical scan angle, then you're probably OK. You'll still hear your scanners protest when you push them wide open though - at least when displaying the ILDA test pattern.

Bottom line - you need to see how wide you're scanning. If they're scanning very wide, then there are patterns that could cause damage. And noisy galvos are a bad sign. Crank the size back until they quiet down.

Adam