# Liquid sky mirror help needed



## Tokwik (Oct 12, 2011)

I started a discussion in a different thread and completely thread-jacked it from the OP and decided it would be better to start a new one instead.

What I am working on is a liquid sky effect using the mirror off of an old laser printer. What I would like to do is utilize the existing mirror board and mounting setup with the IR laser removed and replaced with my 5mW green one.










Now as I have come to find out, thanks to David_AVD and his wealth of knowledge, is that I am dealing with a multi-phase motor and powering it up is going to be more difficult that I thought.

SM5564-070










Where I am looking for help and insight is finding out how to make this work. I know I could simply remove the mirror and mount it to a fan or something, but where's the fun in that? 

I did find on the other forum where someone used a resonator to keep the motor running, but they were using a different board with a different chipset. Linky

The problem still lies in that I have know idea how to do a similar setup with this board because I can't seem to locate any helpful information on it; Input voltage, resonator frequency, or chip map.

Any help would be greatly appreciated.

Thanks.


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## niblique71 (Dec 2, 2009)

If it was me I'd remove the "C" clip and mount the mirror to another motor. make an adaptor if necessary. I am HUGELY Curious though if you manage to power that original motor with a simple soulution. Could be VERY COOL. But I believe that you have already inspired a huge amount ot tinkering. So TOUCH'E for your contribution.;


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## corey872 (Jan 10, 2010)

Wow, when you said use a laser printer mirror, you really meant 'use' the laser printer mirror! If you can't use that motor, then I'm not sure the rest of the set-up gives you much else either. All those lenses are probably going to gobble up half your laser power and they are trying to focus the laser to a straight / flat plane (ie - make it hit the sheet of paper uniformly) That is not really what you want for the liquid sky either...unless you only want the 'sky' to be 8-1/2 inches wide!

I guess you may be able to rig something up with a 555, but seems like it would be much easier just to pop the mirror off and glue it to a small CPU or other cooling fan.


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## David_AVD (Nov 9, 2012)

I just fished around in my junk pile (err.. treasure trove!) and found the original laser assembly I was talking about in the other thread. It uses an NBC3111 chip and while searching for the data sheet, I came across this video. I tested mine with a 12V supply and 2KHz square wave (from a function generator) and it does spin up pretty fast.


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## Tokwik (Oct 12, 2011)

corey872 said:


> Wow, when you said use a laser printer mirror, you really meant 'use' the laser printer mirror! If you can't use that motor, then I'm not sure the rest of the set-up gives you much else either. All those lenses are probably going to gobble up half your laser power and they are trying to focus the laser to a straight / flat plane (ie - make it hit the sheet of paper uniformly) That is not really what you want for the liquid sky either...unless you only want the 'sky' to be 8-1/2 inches wide!
> 
> I guess you may be able to rig something up with a 555, but seems like it would be much easier just to pop the mirror off and glue it to a small CPU or other cooling fan.


The CPU Fan plan is the fallback. I've built the laser vortex tunnel that way and it came out pretty decent. I'd like to see if I can get it to work on the board "as-is" if possible and within reason.

As far as all the lenses, I honestly have no idea what they do and have no problem whatsoever in removing them. If they only concentrate the beam to paper size, then they will be gone with the quickness. I haven't tried what it does with the 45* mirror at the end removed yet.

***edit***
OK, looked at what the lenses do for correcting distortion for the printing. I can't see any reason to keep them for this application.



David_AVD said:


> I just fished around in my junk pile (err.. treasure trove!) and found the original laser assembly I was talking about in the other thread. It uses an NBC3111 chip and while searching for the data sheet, I came across this video. I tested mine with a 12V supply and 2KHz square wave (from a function generator) and it does spin up pretty fast.


Holy crap that thing spins fast!
As I mentioned in the other thread, thanks again for all your help.

Do you think if I can figure out the resonator frequency for this board if that trick would still work? Or would any frequency do the trick? The one posted in the link for a different board appeared to be using a 20 MHz.
I still have no idea what pins to jump yet though.

I've found replacement boards that specify between 1.5V and 5.0V supply voltage, but I'm thinking that may be limited because of all the other circuitry to make this thing work as a printer. DIY pages have been turning up between 12V-18V DC works to make the mirror spin. So I'm guessing just about anything will do depending on how fast you want it to spin. Haven't come across any firm Amperage numbers yet though, so I don't want to fry the whole thing in a puff of smoke. 

Once again, I appreciate everyone's help.


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## David_AVD (Nov 9, 2012)

Tokwik said:


> Do you think if I can figure out the resonator frequency for this board if that trick would still work? Or would any frequency do the trick? The one posted in the link for a different board appeared to be using a 20 MHz.
> I still have no idea what pins to jump yet though.


Without a circuit diagram of it, I don't know how the resonator trick works exactly. 20MHz is far too high frequency for a motor drive, but it may be that it's really the load capacitors inside that 3 pin resonator that are determining the running speed.



Tokwik said:


> I've found replacement boards that specify between 1.5V and 5.0V supply voltage, but I'm thinking that may be limited because of all the other circuitry to make this thing work as a printer. DIY pages have been turning up between 12V-18V DC works to make the mirror spin.


I tried mine with a variable supply. The minimum it would run on was about 11V. I would keep it on the low side. The speed is determined by the frequency you feed it, but I did find that about 2KHz was the sweet spot for mine. Lower than 1KHz caused unstable operation and going a lot higher than that didn't increase the speed any further and could cause problems for the driver IC (heat up and die).


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## Cole&Jacksdad (Jan 20, 2011)

I found an easier way.


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## Tokwik (Oct 12, 2011)

Yes, I have seen that video. Sometimes keeping it simple is the best way but I'm not sure that will work for my intended application. 

I've tested out something similar using the laser line from a construction level and it does indeed project a horizontal line on the opposite wall of the room. Unfortunately, the "field of view" coming from the laser is extremely narrow (maybe 30*-45*) and widens as it gets further away.

The setup I am trying to accomplish (the hard way) is to fill the entire floor of a room. I believe the FOV at the mirror will be around 120* or so. I'm hoping to be able to place the laser setup in the corner and have the effect projected around all four walls.

Go video though, thanks for posting. I'm sure someone will be able to use that technique.


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## Tokwik (Oct 12, 2011)

David_AVD said:


> The minimum it would run on was about 11V. I would keep it on the low side. The speed is determined by the frequency you feed it, but I did find that about 2KHz was the sweet spot for mine. Lower than 1KHz caused unstable operation and going a lot higher than that didn't increase the speed any further and could cause problems for the driver IC (heat up and die).


That's extremely helpful. I appreciate you doing that testing.

I'm still hunting for a circuit diagram but it sounds like you narrowed down the voltage and the frequency a good bit.

Thanks again.


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## Cole&Jacksdad (Jan 20, 2011)

Tokwik said:


> The setup I am trying to accomplish (the hard way) is to fill the entire floor of a room. I believe the FOV at the mirror will be around 120* or so. I'm hoping to be able to place the laser setup in the corner and have the effect projected around all four walls.


I saw 120* len's on ebay for about $6.


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## Tokwik (Oct 12, 2011)

Cole&Jacksdad said:


> I saw 120* len's on ebay for about $6.


Awesome, thanks.

If I can't get this overly complicated method to work, then I'll definitely be trying that route.


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## Cole&Jacksdad (Jan 20, 2011)

Here is one for $3.50.
http://www.ebay.com/itm/Line-lens-1...498?pt=LH_DefaultDomain_0&hash=item5882749532


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## corey872 (Jan 10, 2010)

There are certainly many ways to skin this cat! I'd posted about the laser lenses in the other thread and as they have been followed up here, you can see they are pretty cheap and available in a wide range of angles. If you can fit the laser in a corner, I'd think a 90º spread should cover the whole room.

I will also submit another way to do this. Just use a glass stir stick or other similar glass cylinder. Note, this video is just a 'proof of concept'...my batteries are mostly dead, so the laser isn't real bright, I had a 3/8" diameter glass rod, but a thinner rod would make a wider beam, the fog is 'hot' so it doesn't want to stick around the table top too long and some ambient light spoils the effect. But given all that, you can see putting a glass cylinder in the laser beam makes a decent liquid sky.


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