Weird distortion on galvos?

[megaton]

Hi all

On my set of DT30s when I display a ILDA test Pattern (12K).
The Horizontal Red line in the middle (x axis) looks with little waves.
But when I eliminate the blanking jumps disappear.
And looks fine.
(and in some other few frames have the same defect and correction).

I'm displaying at 20kpps and at 13% size. (I calculate that, with the distance, wide formula and is around 10º approx.)

With my scanpros 30ks looks fine. But the ground wire on this, are not connected as said
on the specs.

Is normal or I have to disconnect the ground wire on this too?

Any Ideas?
Thanks and cheers,
Ed
BTW my mirrors on this set are wider.
And sorry for my English.

[LaNeK779]

i am no expert in this, but i seem to remember that in previous posts other people faced the same problem and it was all due to a not-so-optimal grounding scheme, ground loop or something of the kind.

some phantom ground must be getting through and messing up your projection

i hope someone can phrase this more appropriately...

[megaton]

i am no expert in this, but i seem to remember that in previous posts other people faced the same problem and it was all due to a not-so-optimal grounding scheme, ground loop or something of the kind.

some phantom ground must be getting through and messing up your projection

i hope someone can phrase this more appropriately...

Thanks Lanek
Now searching for grounding problems.

Cheers,
Ed

[badger1666]

Hey when building a projector you connect all the grounds to one point in the
Projector,its called star grounding, and it stops ground loops forming ,and they can cause
Interference, search on here or google star grounding

[megaton]

Hey when building a projector you connect all the grounds to one point in the
Projector,its called star grounding, and it stops ground loops forming ,and they can cause
Interference, search on here or google star grounding

Thanks Badger

I'm reading something in Pangolin Web site about star grounding and I think this is it.
But really, I don't yet understand all.
I'm gone start doing some tests.

Cheers,
Ed

[-bart-]

Check if (one of your) laser housing(s) is grounded to the baseplate where it shouldn't be.
Isolate them from the baseplate asap, your diode driver does not like this situation either.

[megaton]

Check if (one of your) laser housing(s) is grounded to the baseplate where it shouldn't be.
Isolate them from the baseplate asap, your diode driver does not like this situation either.

Thanks Bart.

Im gone to check that too.
I isolate the diodes but I don't now if the DPSS is?.
Now is 3:15 AM here and is time to go for now.

Thanks and cheers,
Ed

[badger1666]

You dont need to isolate dpss lasers from ground, only non tec cooled home made lasers need isolation,except 445nm builds as thr diodes are already isolated,

[LaNeK779]

so, after all the above, either check the reds or check the galvos mounting block or a switching psu case

hope you figure it out

cheers!

[michelrietveld]

when i started to see distorted lines, with wave like shapes, it was because one of the mirrors was starting to get loose and broke off a little while after i started to investigate.
One clue was that if i painted a square i could see the horizontal lines straight and the verticals showed the sinus wave form distortion.

Michel