Out of Alignement (QuickTargets Beams in Pangolin QuickShow)

[rfourt]

Im going to post this to Pangolin also. But just wanted to Check if anyone here has had this error also.

Yestarday i had a big show here in sweden, but discovered something very strange with either my scanners or Pangolin Software. or something else.. REALLY strange.

Im using alot of BeamMirrors that i putt up in the venue. about 10-30meters away from the laser. And for them i use the feature "QuickTargets Beams". Istarted to set the "Beam 01" to hit the first mirror about 25meters away, THen i continue with the "Beam 02" and hit the second mirror about 10meters away. and so on.

After about 5min i went back to check the first beam and then it happend.. It had walked out of alignement about 2-4centimeters.. And if i waited about 15min more it was not even hitting the mirror about 10-15cm out of alignement.

I checked the software but everything seems fine, so i tested to realign again and wrote down the X&Y numbers and waited 20min to see again.. And yes, all 20 Beams that i set up had walked out of alignmenent.. Some more then others, but the numbers where not changed.

So what can couse this?

I checked the following:

1. The laserbox/system was perfectly stable and not rubbed or pushed etc. Firmly fastened.
2. The Galvos are really tightly fastened into place.

I have no clue what coused this problem. really enoying and my show was not 100% last night.. Remember 20meters away is very small out of alignement at the laser, about 0.5mm i would guess. But still.

When i walked to the wall about 25meters away to look at the Dot from one of the beams, the dot seemed to vibrate/flicker up n down very very tiny..

So DOes anyone have any idea what can couse this?
electromagnetic interfearance?
Ground issues?

thnx for any input.

/Rickard
ps: sorry for spelling. only sleeped for 4hours on my way to the airport.

[VJ AIWAZ]

the vibrations sounds like 60 cycle hum or other ac interference

but as for the targets moving did you first allow the galvos to total warm up and settle in to a stable temperature if not try that galvos are known to walk a little as they thermally settle

[rfourt]

the vibrations sounds like 60 cycle hum or other ac interference

but as for the targets moving did you first allow the galvos to total warm up and settle in to a stable temperature if not try that galvos are known to walk a little as they thermally settle

Thanx for your fast answer.

but what is 60 cycle hum?
yes the AC interference sounds like it can be somethig like that. i have one of the PSU´s to my Green 1.7W screwed to the breadboard. so mayby something there gets transmitted.

Ok.. didnt know that, but yes the galvos where on for about 1hour before and during the alignement.

[VJ AIWAZ]

oh sorry your not in the US so it would probably be 50 cycle hum

basically its the rate at witch the ac flip flops in the states it does it at 60hz but i believe in Europe its is 50hz


http://en.wikipedia.org/wiki/Mains_hum

[-bart-]

To my knowledge drift is not related to hum.
Hum and drift are separated problems.

Biggest source of drift is thermal walk-off in the position detectors.
And there may be stability issues in the galvo driver too.

Exactly what galvos do you use, and with which drivers ?

[Shawnb]

i have had the same issue with the beam targeting loosing its "memory" and being way off from the target. however i have not had any "vibrations" and the issue only seems to happen when i run the FB3 hard with lots of stuff going on. i also have had quickshow stop outputting target cues when switching animation cues and could only recover by hitting escape and restarting the cues.

[johnpoe12]

Hey im in stockholm for the next week. Hit me up if you have another gig

[mccarrot]

Try to warm up your galvo's first befor setting the beams, maybe this helps?

[sbk]

I had this issue too, with Pangolin LivePro. The beam lost its position as soon as I was jumping from Beam1 to Beam2, and then back to Beam1 the laser beam wasn't any more at the same place, although not moved in the software.

This was repetable, I tryed tenths of times with always the same results! I'm interested to hear if there was a solution to this problem...

[rfourt]

Hey im in stockholm for the next week. Hit me up if you have another gig

oh.. oki.. nice.. long way from home?, may i ask what brings you here?
I might have a show on Friday but not confirmed just yet.. I think i will know for sure on Wednsday.

Try to warm up your galvo's first befor setting the beams, maybe this helps?

Read below.

I had this issue too, with Pangolin LivePro. The beam lost its position as soon as I was jumping from Beam1 to Beam2, and then back to Beam1 the laser beam wasn't any more at the same place, although not moved in the software.

This was repetable, I tryed tenths of times with always the same results! I'm interested to hear if there was a solution to this problem...

Oki.. yes it might be same problem now i have.

I will tomorrow do some major testing at this. putting atleast 3 different beams at 20meters away.

There might be something about the warming the galvos up thing. even though i had the galvos run hard about 1hour before i set the beams. Although the place i was having the show at had a really low ceeling/roof so i had shrinked the Projectsettings display field to about 10% in height only. ANd when i feelt the galvo drivers heatsink a couple of times that night as i usually do, becouse they normally tend to be quite hot, but now they wasnt even warm. more like cooled. So perhaps becouse i had shrinked the display field down to 10% in height the galvos never got to correct temperature..

But as i said i will do some testing tomorrow at Full display Field and see if the beams seems to start moving out of alignement. and if they dont i will let the galvos cool down and shrink the display field down to 10% and do same test again.

stay tuned.