Galvo drift problem - newbie question

[mixedgas]

Sounds like you hit the coil temp limiter circuit..
Steve

[Stoney3K]

Sounds like you hit the coil temp limiter circuit..
Steve

Or just a galvo running the edges (clipping) and not being aware of it? That would also cause it to heat up quite a bit....

When you hear a high-pitched screeching sound from your scanners if a frame is running, you know something bad is going on.

[santanas]

Today,

I took the projector apart and I didn't found anything special about the mechanics. The Chiller Spray also had no effect. So today I focused my attention on the amp tuning (I never did that before) and decreased the output size. The drifting disappeared and I'm happy now ;-) In the near future I will buy a new Scanner-Set, perhaps something more expensive... @ all: Thank you very much for the quick help !

Hi. Did you get a manual for tunning on your projector? Which Pot is the gain on the 20kpps amp? I dod not get the manual with mine and trying to get from Laserworld. Thanks JH

[Nevermind29]

Unfortunately I got no manual for the scanners, but the layout of the lw-50k scanner amp seems to be very similar to the 20k except of the "offset" pot... Actually I turned all of the pots anti-clockwise to zero and after that increased the values one by another until I got the best result. In fact, it wasn't too difficult to do, but I'm sure this is not the right way of tuning...

[Insanity]

Actually I turned all of the pots anti-clockwise to zero and after that increased the values one by another until I got the best result. In fact, it wasn't too difficult to do, but I'm sure this is not the right way of tuning...

Buffo has a good tuning guide which you can find on here with a search. If you have changed the tuning, make sure you can still scan the ILDA test pattern ok, otherwise you might need new galvo's sooner than expected

A tip with Laserworld scanners is to leave them scanning the ILDA test pattern for a good half hour before tuning anything. I noticed that I could tune a 50k set to a near perfect test pattern @ 30k - 8 Deg, but the next time I fire the projector up they were way out... Leave it running half hour and the pattern is perfect... I did post photo's in a thread some time ago, but can't remember which one...

Still, get hold of Buffo's guide and check your test patterns before you scan anything full angle...

Mark

[buffo]

The latest version of my scanner tuning tutorial is being graciously hosted by Dave and Adrian over at LaserShowParts.com. Here's the link.

One thing I can't stress enough: Make sure you know which pots are which before you start! You can really screw up your tuning if you get this part wrong. At a minimum, you need to identify the pots for Servo Gain, High Frequency Damping, and Low Frequency Damping. I suggest you label them so you won't get confused while tuning.

Adam

[Nevermind29]

Thanks again for the advice, I will rethink my setup today...

[santanas]

Here is the message from Laserworld on Galvo tunning.

Hi John,sorry we are still a bit behind with the manuals, I hope I can finish it this week.On the driver board you will find 3 pairs of pots, if you look at the driver so, that the pots are on the downside, then the pair on the left is for size (both directions), the other two pairs are for gain and damping (although the drivers work a bit different, so it's not exactly gain and damping as on the drivers for the LW-50k, but you will see how they work, as soon as you try), one pair of pots is gain/damping for one direction.Sorry again I have no better documentation, if you have further questions, don't hesitate to send me an email.With kind regards / mit freundlichen Grüssen, Peter Mayer