PT30 help!!!!!!

[nuphotonix]

OK after installing the new pt30's I have noticed a problem right off. The prior 12k galvos and amp only used the (+) and the OV post. but my pt30's have a (+) (-) and OV post. When I use the cables that fit the cloner dmx board, only two wires are being used.

1. Do I need all three wires for the pt30 to work?
2. Can I just use the (+) and (-) posts instead and omit the OV post?

(OV)= as labled on the PDF blowup with no explination as to it's significance.

Currently when I hook it all up for benching, all I get is static scribbles. w/no control over the scanners.

Thanks!

[whatsupadrian]

I am sorry to threadjack but since we are on the subject. I had a set of PT-30ks that i bought 4 months ago. Something happened and the scanners failed so I ordered another set from the group buy. My original set also came with the PT-ITrust DMX Show card. Well everything failed so I removed it all and installed the new set of scanners but with no DMX board. I wired up the XY RGB wires all up the the ILDA cable directly(also omitting the 0v ground wires from the driver amps since the DB-25 e doesn't call for it), I shorted the interlock pins and fired it up. Right off the bat things look different than with my last setup. First of all, in quickshow with the scan area at maximum, I used to get a good ilda test pattern at 24k. Right now the pattern doesn't look good unless im at 14k. Even at that speed the circle in the middle is oval shaped like the image posted below. With the test pattern with all the different colored circles, all circles are oval shaped. Also have some tails at the end of some patterns and some of the circles dont complete. What could be the cause, did they ship cheaper galvos with the group buy?

...Now when I snipped the wires from the galvo amps. the 0v wire is actually a sheilding. Could I be experiencing some sheilding issues with my galvo amp wires or does it seem like a grounding problem? Should I short the 0v wires that sheild the galvo amp wires to the db-25 case screw or pin #25?

I spoke with spacelas and I am going to be shipping my messed up galvos back to china as they are only 4 months old. They seem to think i got some humidity problems which is strange because the projector hasnt been outside yet.

ildatest.JPG

OK after installing the new pt30's I have noticed a problem right off. The prior 12k galvos and amp only used the (+) and the OV post. but my pt30's have a (+) (-) and OV post. When I use the cables that fit the cloner dmx board, only two wires are being used.

1. Do I need all three wires for the pt30 to work?
2. Can I just use the (+) and (-) posts instead and omit the OV post?

(OV)= as labled on the PDF blowup with no explination as to it's significance.

Currently when I hook it all up for benching, all I get is static scribbles. w/no control over the scanners.

Thanks!

I can confirm that the 0v post is a ground wire. the wire actually sheilds the + and - wires from interference which is probably where I am having my problem. I'm sure someone will chime in soon that actually knows. I'm thinking you have to ground out those 0v pins for it to work properly but IDK for sure. Maybe try grounding out those 0v wires on the DMX board somewhere.

[Xytrell]

That looks more like a tuning problem than a shielding problem to me.

[whatsupadrian]

That looks more like a tuning problem than a shielding problem to me.

I can go with that. The both sets of scanners have been left on factory settings. My original scanners seemed to perform much better so I can see how tuning would solve that but they came from the factory like this. The PT-30 manual says nothing about how to tune the galvos. Is there a galvo amp tuning guide anywhere. I tried the search function.

[whatsupadrian]

Not sure what my scan angle is, using 50% x 50% on QS. This is what my circles are looking like, oval shaped. dont really get round till i turn the scan rate down to like 14-15k, this is 30k i thinkDSCN2275.JPG

15kDSCN2282.JPG

20kDSCN2283.JPG

25kDSCN2284.JPG

30kDSCN2285.JPG

My other set of PT-30's was giving me round circles, they didn't complete and meet in the correct place till about 24k but it was round.

[nuphotonix]

thanks for HIJACKING my post.. i repost it agan..

[swamidog]

Does "0V" mean ground?

OK after installing the new pt30's I have noticed a problem right off. The prior 12k galvos and amp only used the (+) and the OV post. but my pt30's have a (+) (-) and OV post. When I use the cables that fit the cloner dmx board, only two wires are being used.

1. Do I need all three wires for the pt30 to work?
2. Can I just use the (+) and (-) posts instead and omit the OV post?

(OV)= as labled on the PDF blowup with no explination as to it's significance.

Currently when I hook it all up for benching, all I get is static scribbles. w/no control over the scanners.

Thanks!

[Xytrell]

Is there a galvo amp tuning guide anywhere.

http://lasershowparts.com/files/Arti...20Tutorial.pdf

It is a lot of work, and you can potentially ruin the scanners. You might want to consider sending them to someone who has more experience.

[whatsupadrian]

Right, anyone in So Cal with tuning experience?

[LaNeK779]

http://lasershowparts.com/files/Arti...20Tutorial.pdf

It is a lot of work, and you can potentially ruin the scanners. You might want to consider sending them to someone who has more experience.

don't get intimidated, it is a really well written guide. if you follow through you'll be fine

by the way, a big thanks to buffo for writting this

[whatsupadrian]

Im definitely going to try then when I get home today. Looks straight forward and great detail in that write up. It would now appear that one of my scanners is tuned faster giving me that oval shaped circle, however I am going to follow those directions exactly and dial everything down and start from scratch. Wish me luck.

[LaNeK779]

if you go through the text a few times before you start and have time, space and quiet, you will not need luck
besides, if you keep turning each pot 1 turn at a time (max), you can't screw anything up

[whatsupadrian]

One turn at a time.... Ill try that again tonight. Last night I spent about two hours turning those pots to have the galvos completely get away from me 3 times. I managed to get it pretty close but its impossible to see the overshoots and undershoots, i think my lasers are much too bright for the test, even turning then max sliders all the way down in QS its really bright. I'm sure i got the hang of it now though, pretty sure ill make it perfect later today. One thing
I am a bit confused about is the scan angle i am tuning for. The manual says the scanners are factory tuned to 20º@30k, the website says 25º@30k. So it seems that the angle I want to tune for is 20º. Now going by the guide it says to increase the angle in software till the circle stops getting bigger, how do we tune to this scan angle with this procedure? Am i missing something?

[LaNeK779]

Now going by the guide it says to increase the angle in software till the circle stops getting bigger, how do we tune to this scan angle with this procedure?

this is a point that confuses me too, so i don't use this, i just use stanwax angle guide http://www.stanwax.plus.com/lw/scananglechart.pdf to calculate the angle and projection size

but some input on the circle stopping getting bigger should be useful

[taggalucci]

but some input on the circle stopping getting bigger should be useful

When you have a reasonably stable square-ish image, it is possible to establish the largest scan-angle the scanners are capable of by performing this. Basically, the circle's drawn points are actually bigger than the square, but as you speed up the rate, the galvos can't keep up and the circle gets smaller. When the circle is the same diameter and the width/height of the box, the scanners are at their optimum.

So a combination of desired rate and scan angle adjustments are what is used to achieve this, using the circle and square as your guide.

Clear?

[LaNeK779]

yes, it is clear, thank you

so, in this pic i have to increase the scan size or increase the scan rate (or a bit of both)

but why does the circle not close and leaves this silly dangling end?

[taggalucci]

Increasing scan size = increasing gain.

If the circle doesn't meet then there's something else wrong. Only when the circle resembles a circles or oval can you mess with the scan angle. Only once you you have a square/circle can you mess with the other settings!

Easy 'ey!

[LaNeK779]

oh well, now that i come to think about it, i have the same issue with three sets of scanners, two of which are as tuned by the factory (and they are not cheap no name ones) so, maybe it is the dac's fault...

anyway, thanks for doing this, i'll try it again a few times over the weekend, it gets easier every time

[spacelas]

The main reason is because of the magnetic force of Y and the IC in Y



--------
shop.spacelas.com

[LaNeK779]

By the way, the pic above, comes from PT 40 scanners.
The projection size is 1 meter at 3 meters distance (unless i am way off, this is 20 degrees)

Any idea of anything i could do to make this project a circle?

[taggalucci]

If you're running your scanners at your desired rate, I would increase the size (in software if you have the size not at 100%) or gain on the drivers. The important thing is to get the circle close to the size of the square. If you change the gain you need to be careful to do this slowly and adjust the LF and HF damping to compensate as required.

It can sometimes be better, especially if you've not tuned scanners before, to follow Adam's (Buffo) excellent scanner tunning guide. This way you should end up with the scanners optimised for the size and rate you want to use.

Always tune slowly and carefully in case you unbalance them. At the first sign of instability, turn the adjustment back and move to another of the adjustments to compensate.

[LaNeK779]

i have two nieces on the way here for the weekend (one is 4 the other is 1.5 years old, so this does not seem like the weekend to be practising my tuning skills...)

i'll let you know once the infant-hurricane has passed. thanks again for your help

[taggalucci]

No worries mate, good luck with the kids (rather you than me)!