Grounds for murder?

So, Top recap another thread: I've just gotten my FB3 and I am currently putting together my projector. After wiring everything up and making sure it works (works perfectly, thanks to it's Bill Brenner tuning/modding) I was attaching the X axis scanner amp to my base plate when one of the actors on this tour came by to check it out. After talking for a bit (I'm working on this the whole time), he smacks me on the back of my right arm in a "good buddy" sort of way, knocking one of the trim pots off my x amp in the process! I pushed it back into place, praying that it's ok, but I have yet to fire them up and test them. I know that I can probably get the part at an electronic mart here, and possibly even tune it back, But right now I REALLY want that kids head on a plate.

In case you guys were wondering, it's part number r28, a 10k ohm trimmer pot that's labeled SGA on the document I have for it. that's the "servo gain" pot, so it seems that I can replace and re-tune without too much worry.

Jian, Can I just replace this part and re-tune it myself, or should I send this out to you? Keep in mind, I sent these to Bill Brenner and he did his mod to them.

I'm going to go have a beer and try to calm down.

If the pot does need replacing, measure the resistance, and adjust the new pot to the same resistance before replacing it. This will probably get you pretty close

That's good advice, Dave, thanks.

I will definitely have to replace the pot, at least one of the conductors has been broken off. I'm not actually sure that I can get a measurement off of it, but I plan to measure the same pot on the Y amp, this will at least get me to a place where I won't kill the galvo on power up.

I'm done tinkering with it for tonight, I'm going to pick it up again tommorrow.
but hey, at least when I get this fixed it'll be up and running.

Even with the legs broken off your multimeter probe should still make contact.
Don't forget that if you take a reading off the Y pot while it is still in circuit the reading will be effected by other components.

Jim

Mr Coffee;

Did you yell at the actor? Does he know what he did? (I promise you he would have known what he did if it had happened to me!)

Grounds for murder? Me thinks not. But I'd be seriously pissed off if I were you. The guy sounds like a jerk. If he had any decency he'd offer to pay you for the repairs.

I think you'll be OK just replacing the pot and soldering it in place yourself. Get a good measurement of the resistance on the old one, and set the replacement one to the same setting and you should be fine.

Worst case, you might want to send them back to Bill to be re-tuned - assuming that you don't feel comfortable doing it yourself. But in that case the "actor" that caused the problem ought to pay for the shipping...

And in the future, remind the asshole that lasers are expensive, and that you'd appreciate it if he'd just leave you alone when you're working on them.

Adam

it shouldn`t be too hard to get your own back on him, actors do tend to be easy targets (a bit like roadies, but more gullible):D

Hey guys. First off, thank you so much for your quick and very helpful replies, I probably would have thought about the component swapping logistics when I calmed down, but I'm glad that you guys were here to steer me in the proper direction.

as far as the actor is concerned, once he realized what happened, he was very apologetic. he offered to cover any repair cost, and even shouted me a couple beers at the bar. Im about to put the new pot in, so in about an hour you'll get either a very happy post, or a very angry one.

once again, Thanks for all your help, guys and gals, I really appreciate it.

UPDATE: so I matched the resistance as best I could and put the pot back in. Both scanners move, but the images are not recognizable at all. I'm not sure if this is a tuning issue or what. I'll bring a camera in tommorrow and show you guys pics of the test pattern, but it is very distorted, and the outer test pattern box (not the really big one, but the outside of the pattern), is nonexistent, and there are two vertical lines to the right of the pattern. I'm not sure if this is just wildly out of tune, or if some part of the board is messed up. I emailed Jian to see what he says. I'll wait for you guys to see the images before I make a decision, but my options at this point look like this:

1) it's not broken, just out of tune:

a) I'll try to retune the x amp, since the y amp hasn't changed, I should
be able to leave that where it is, right?


b) I send the scanners back to bill (assuming that's ok) for what must
set the record for the shortest time between tunes.

2) It is broken:

a) I send the scanners (or just the x amp) to Jian for repair. He sends
them back to me, and I try to tune them.


b) I send the scanners to Jian for repair, and have him send them to Bill
for the aforementioned record-setting tune-up


I'm trying to decide how much I should make the guy pay, It was an accident (a really, really dumb one), and this guy doesn't have the greatest track record, but at the same time, we're all human, and this guy doesn't make a lot of money. I figure I'll ask him to go 50/50 with me on repair costs, but we'll see what those turn out to be.

but man, for the 15 minutes I had my projector working, it was awesome...

ah,well. C'est la vie I suppose.

I think if you have any doubts, send the scanners to Bill. Bill is the guru period ;) . Oh, and make the person pay for everything ;)

If you end up having to send the scanners back to Jian, I agree that having them sent straight to Bill afterwards is a smart idea. That way when you get them they should be perfect.

Were the scanners powered up at any time before the pot was replaced? (That might have caused more damage.) If not, then it's possible that some other component was damaged when he hit your arm in addition to the pot breaking off. Having a stray line(s) off to the right like that sounds very strange. Maybe I'm just not visualizing it properly, but that doesn't sound like just a tuning issue to me. (A picture will help a lot.)

One thing to consider though: If they are broken, adjusting the tuning won't hurt anything. So you can play with the tuning a little bit and see what you can get. And you are right, the "Y" amp should be just fine, though it will need to be tweaked to match the X amp once you get the X amp dialed in again.

Something else to consider: If you have to send it back, Jian may decide to send you a replacement set instead of a single galvo. (You're going to have to re-tune the set anyway, even if he only sends you one galvo and amp.) Ask him about that if you end up returning them.

Adam

Update, round 2:

So I thought about the situation last night, and I figured that since both the galvos are turning, that it is probably just a tuning issue. when I got into work today, I cracked open that pot and found that I'd set the replacement off by about 5 kohms or so. I adjusted it and presto! a recognizable image. the only problem is that at wide scan angles, the x amp seems to collapse and I have to reset the scanners to get it back (perhaps that polyswitch is doing it).
I have pics of what it looks like now, as well as what it looks like after the scanner collapses. on the third pic (I can't remember what the name of the test pattern is called), when I adjust the scan rate down to 8k, the image looks great, the corners are nice and crisp, and everything lines up. at 30 k, the image causes the scanners to collapse after about a minute or so. (needless to say, I try not to display it for very long).

Long story short, I think it's just a bit of a tune job away. when I get back to the states (mid april), I'll probably send them back to Bill for a once-over. But again, thanks for all your help throughout this.


ok, enough chatter, here are the pics:

1 and 2 are the same thing, but 1 is a crisper image (though my body was blocking part of the pattern. 2 is a full image,but is shaky.

three is the diamond test pattern.
the fourth is the diamond pattern after the scanner has collapsed and the fifth is the standard ILDA test pattern on the collapsed scanner (before I reset)

Are you scanning the ilda at full angle at 30k?

Yeah, it's at 30 k and full angle (I haven't found out how to adjust the scan angle in livequick yet).

all the images were taken at 30 k, full angle, which Could be part of the problem itself.

Looking at the photo's the tuning on X looks very good, y is a little off but that doesn't matter since its X thats collapsing. Throw a solder bridge over that polyswitch and problem solved... Or do what I haven't had a chance to do, remove the poly switch and test it to see if its still in spec!

Quote:

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Originally Posted by Mr.Coffee

Yeah, it's at 30 k and full angle (I haven't found out how to adjust the scan angle in livequick yet).

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You can adjust the scan angle amongst many other projection related settings under-> Settings-geometric correction in LiveQUICK :)

Thanks, Dave. I actually found that, and have limited the size to 70%. I figure while I'm playing around with this thing that I don't need the image to be huge anyway. I guess I should crack out the calculator and find out the scan angle.
I was really hoping that there would be a scan angle setting directly, but ah well.

but now I see what you guys are talking about regarding the noise issue with blue dpss, mine's got it as well, but I figure that's just something I'll have to deal with, along with the temptation to drop 2 grand on a red and green to get this up to full-color. that's a battle I plan to loose eventually, but at least not until I've picked up another tour ;-)


learning curves are great, aren't they?

It would be nice to have a scan angle setting - although it would be something you would have to manually calibrate with every different set of scanners, since they are all different.

A scan angle setting is not a bad idea. I think I will add that to my software and will allow the user to calibrate it by entering measurements of a square that I project and the distance from the projected image to the scanner. Thanks for the idea.

Haha yeah when I typed that in I was thinking... hmmm Pangolin could benefit from this :)

So does spaghetti work with the FB3? I would like to try out the software

Mr Coffee;

Even a scan size of 70% may be too large for your DT-40's, at least when displaying a complex pattern like the ILDA test pattern. They're only designed to do around 15 degrees optical at 30Kpps. If you're running a complex pattern that is significantly larger than 15 degrees, that protection circuit is going to kick in every time. (Truthfully, that's what it's there for.)

You can scan simple stuff at greater than 15 degrees, but the ILDA test pattern has a portion (the center circle) where the scanners are running flat out (ballistic), and if you push the scanners beyond their limit while displaying that pattern they will just draw more and more current and get really hot while the pattern degrades. Eventually that poly switch will kick in.

I had this problem crop up quite a few times with my scanners. The solution is to back off on the scan size when running complex stuff.

When you tune your scanners, you should start with the scan size set very small and then bump it up a percent or two at a time. When you get to the point where the center circle in the ILDA test pattern stops getting larger, *STOP*. Back it off a percent or two and then tune at that setting. You'll find that the pattern will look a lot better! (And you still should be in the range of 12-18 degrees, depending on how good your DT-40's are.)

Adam

Yeah, I haven't tried to tune it yet, but I realized the size issue yesterday. I downloaded your abstract show,and my scanners wen't nuts (I really hate the fact that showrider defaults to the maximum scan size, does anyone know if there's a way to change that?) I was playing with the little wobbly cone thing as well, and that kicked it when I got too big as well. fortunately, the stuff I'm playing with in live quick is simpler stuff, and that's where I have the 70% cap. Im going to look at showrider, and try to set it even smaller, 50 or 30% maybe, assuming I can figure out how.

also, have any of you noticed that your fb3 drops randomly? mine has a couple of times, I reinstalled the drivers to see if it will fix the issue, so we'll see how that goes.

You downloaded my abstract show? The one set to "Clocks", by Coldplay? I thought I saved that in .ldb format... How did you open the file? (I thought showrider used it's own proprietary file format that was incompatible with ,ldb or .lds ?)

If you got it to run, that's great. But yeah, some of the abstracts in that show are pretty complex. They will make your galvos work hard if you increase the scan angle too much. My old DT-40's used to "sing" when I displayed that show at anything above 15 degrees. My new DT-40 Pro scanners can go a bit larger, maybe 20-25 degrees, before I start to notice little imperfections in some of the patterns... (They are a lot quieter too.) But there's no way I can display that show full scale.

Adam

well, i downloaded your file as "clocks.zip", which, when extracted, turned into a "clocks" folder, with three files in it, a a readme text, a clocks.sho, and a file called "clocks" with a picture of a lock, grid and key from top right to bottom left. this file, (or one of the others), has opened in livequick and showrider live, but only as frames that step very, very quickly between themselves, ie, at normale speed it's way too fast for a show, and indeed something that I am almost scared to put across my scanners at full angle, as they're quite musical. neat abstracts, just way to fast, like each abstract is it's own frame.

hope that helps, I don't really know if I gave you information or not.

Where is the abstract show?
What folder is it in?
I can't find it!:confused:

Jim

Hi Coffee,

A few points.

If only one pot is damaged, you know which pot *might* need to be adjusted. You can adjust that singular pot for the best appearance, and leave the others alone. If you matched the resistance pretty good going in, then not much adjustment should be made -- maybe 2 turns in either direction from where you are.

Second, most test patterns don't look good at full size. So you should definitely reduce the size before making any judgements.

Best regards,

William Benner

Quote:

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Originally Posted by Pangolin

Second, most test patterns don't look good at full size. So you should definitely reduce the size before making any judgements.

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I saw the most significant improvements when I adjusted the pot to the proper setting. the first measurement I got on it was 7.41 kohms, and the second (Which I got by heating a piece of jumper wire and basically reamaking the broken connection on the trim pot) was 2.45 kohms, so I was considerably off. when I readjusted the pot, my scanners came back.

I limited my scan size to 50% for zone 1, once I realized that I was basically driving a dump truck through my scanners. I'm fairly certain this has helped to clean up the test images, but I haven't run them yet (I'm in my hotel room, not a lot of room to set up a laser projector). I'll post a few pics when my friend with the camera gets back.

but again, thank you all for your help, it is much appreciated.

Quote:

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Originally Posted by Mr.Coffee

well, i downloaded your file as "clocks.zip", which, when extracted, turned into a "clocks" folder, with three files in it, a a readme text, a clocks.sho, and a file called "clocks" with a picture of a lock, grid and key from top right to bottom left.

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Right. The .sho file has all the cues in it. The file with the lock, grid, and key is the .ldb frame file that the .sho file uses. (There should have been an .mp3 file in there as well...)

Quote:

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this file, has opened in livequick and showrider live, but only as frames that step very, very quickly between themselves,

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Ahhh. That makes sense. You've loaded up the frame file, and playing it back at 60 frames per second just makes a mess. The show file (.sho) is what controls the timing.

Still, I'm surprised that Showrider Live managed to open up the .ldb file. I didn't think it supported that file format. (Cool!)

If I re-saved the whole show as a single stream of ILDA frames, you could watch it in normal time. The file size would be huge though. (It would be one giant .ilda file that would last for 4 minutes * 60 seconds per minute * 60 frames per second = 14,400 frames!) Maybe if I get some time later this week (before FLEM Mark II) I'll do that and re-upload the ILDA version.

Adam