Help Please tunning

[coil1002]

So after a couple hours of pulling my hair out I am unable to get my galvos tuned. I tried to follow the tutorial but I can not seem to get them to zero to even start the tunning process any help or a fining in the right direction would really be greatly appreciated. The picture will show you where I have left them in fear of getting even further out of tune

Liam

[carmangary]

First, what angle are you at and at what speed? You should be at 8 degrees and 30K (for 30K scanners).

The small circle means you either have them undertuned or your angle is too big for your speed. The squiggly lines could mean noise or could also just be a result of bad tuning.

There is a document on the LaserFX website that tells how to tune them. It doesn't tell you to take them to 0. I am not sure if you really need to do that or not. I have never heard of doing that until Buffo's write up.

You may want to contact Bill Brenner on here (username is Pangolin I think) and see if he will tune them for you. He provides that service free as far as I know as long as you pay for shipping both ways.

[coil1002]

First, what angle are you at and at what speed? You should be at 8 degrees and 30K (for 30K scanners).

The small circle means you either have them undertuned or your angle is too big for your speed. The squiggly lines could mean noise or could also just be a result of bad tuning.

There is a document on the LaserFX website that tells how to tune them. It doesn't tell you to take them to 0. I am not sure if you really need to do that or not. I have never heard of doing that until Buffo's write up.

You may want to contact Bill Brenner on here (username is Pangolin I think) and see if he will tune them for you. He provides that service free as far as I know as long as you pay for shipping both ways.

it was at 30 k 8 degree. The pattern was not that bad until I tried to bring it to zero I guess I could walk my way back up I am just afraid of knocking them out of tune further

[allthatwhichis]

I don't want to offer any advise because I know where you are at. I am not that good at it, but it does take ome practice. I know buffo will be up all night. Hopefully he can post a tip or two. Have you seen the tuning video? There was supposed to be a video. Bill says to bring them down to zero for some reason, and that was on the footage I have. It made sense with the medaphore(sp?) he used. I'll butcher it, so I won't even try to reproduce it.

[carmangary]

Don't be too scared to try to tune them. Just go slow. If they start to make weird noise, turn the screw back the other way.

[coil1002]

Don't be too scared to try to tune them. Just go slow. If they start to make weird noise, turn the screw back the other way.

Ok so I am getting closer any advice on getting the circle round not egg shape ?

[buffo]

Couple things: First, it's not required to walk them all the way down to zero. You can do it if you want (and some of the links near the end of my tutorial describe the process in greater detail) but it's *NOT* mandatory.

Second: at any time you can start going back up the stairs. You're not going to ruin the scanners by changing the tuning so long as you keep the three adjustments (low frequency damping, high frequency damping, and servo gain) properly balanced. The danger is when you get them out of balance too far. (Then the 3-legged stool topples!)

Your last picture looks OK. You're to the point where you need to start using the Laser Media test pattern along with the ILDA test pattern. It appears that you've got some undershoot on your Y axis, so your first step should be to add some high frequency damping to the Y until you get rid of the undershoot on the corners of the square in the center of the ILDA test pattern. Then load up the Laser Media test pattern and check the diagonals.

Remember that the Laser Media test pattern compares the speed of the two scanners. If the diagonal lines are all the same (no evidence of retrace) then the scanners are running at equal speed. If there is evidence of retrace on the upper left and lower right diagonals, then one scanner is faster than the other. (But you can't tell which one is which.) This speed miss-match will cause the circle in the center of the ILDA test pattern to look like an elipse. And often it only requires a small adjustment to fix. (Both low and high frequency damping have *large* effects on the circle - and the Laser Media test pattern diagonals - when you get close to optimal tuning.)

Have a look at the revised scanner tuning tutorial document posted on the LaserShowParts.com website and you'll see pictures of both test patterns with either the gain or the damping adjusted slightly off so you can see the effect on the patterns. That should point you in the right direction.

You are close on your tuning. Get the Laser Media test pattern looking right and then go back to the ILDA pattern and look at the specific parts of the pattern that are talked about in the tutorial. Remember that you may have to go back and fourth a few times. Nonetheless, you should be able to finish the job fairly quickly, as you're already 90% of the way there.

Don't forget about turning off blanking... This is explained at the end of my tutorial, and is a final check to make certain that your scanners are as close to perfect as they can be. (See the pictures in the tutorial for more details.) Also, don't be afraid to move back and fourth between different patterns after you make a change. You might not notice the change on one pattern, but look on one of the other patterns and you should see it.

Adam

[coil1002]

Well after your advice and plenty more reading here I am there is some more that needs to be done but I will save that for tomorrow after sleep

Thank you for all your help and the kick ass tutorial

liam

[buffo]

Looking better.

It's hard to tell from the picture, but it looks like you still have some undershoot on both the X and the Y. So you'll need more HF damping. (This should get rid of the wave in the horizontal lines as well.)

Also, the circle is smaller than the square, so you need more servo gain. But of course, adding gain means both more LF damping *and* more HF damping.

Keep playing with it... You're getting there!

Adam

[coil1002]

Looking better.

It's hard to tell from the picture, but it looks like you still have some undershoot on both the X and the Y. So you'll need more HF damping. (This should get rid of the wave in the horizontal lines as well.)

Also, the circle is smaller than the square, so you need more servo gain. But of course, adding gain means both more LF damping *and* more HF damping.

Keep playing with it... You're getting there!

Adam

Well this is where I got I cant seem to get it better then this any advice ?