Two DIY lightshows - Suggestions for improvements?

For a school project I have built a 50mW red spirograph and a 30mW green liquid sky projector.

This thread, at this stage, is really a work-in-progress but I will be continually updating, answering questions and taking and uploading more videos and\or photographs as necessary. I will have a video of the spirograph and a few pictures up in a few hours and details on each of the projects will be written up tomorrow afternoon. I basically want in-depth questions about my projects and\or about how I built them and which bits you think I did well but most importantly I'd like possible improvements I could make... although there's obviously not a lot that can be said for the moment until I've told you a bit more about them. At the very least I will use this as a space to upload all the pictures relating to my project.

I am submitting a link to this page with my project, so it would be appreciated if you could remain civil (Simon has agreed to help moderate the thread for me since it's quite important), not or edit your posts as doing so can make threads confusing to read and not quote this original post as it is likely I will be changing it frequently. Thanks for cooperating! Also, moderators, please do not delete this thread. If it gets out of hand delete the offending posts, alert me and as a last resort close it but please don't delete. Thanks again!

Ultimately, I will be making a tutorial on how to make something like these, complete with a parts list (at least for British hobbyists) and including the improvements you all suggest (giving credit where it's due ).

Thanks everyone! And hopefully this can work out well for everyone concerned!

The Spirograph
A video of my friend using the spirograph while I record:

He had never used a similar device before, but was able to because I didn't use pots to adjust the speed. Instead I used rotary switches with "off" as the first position, "on" as the second and "on - faster" as the third. I also implemented the ability to reverse the direction of the motors. It is turned on and off by a toggle switch on the side

What it looks like from the outside:



The Liquid Sky Projector
What the inside looks like:


What the outside looks like:


I spent 45 minutes using a standard digital camera, a DSLR and three different ways of producing smoke trying to get a decent photograph or video of the liquid sky projector but it's an incredibly difficult thing to record. Anyone who can provide help with this, it would be much appreciated... I'm really hoping there's some trick to it which I'm not aware of.

Ok! I'm ready for you all to comment now, at least on what you can see so far!

BUMP!

Is nobody going to comment on these?

....
drawn out paragraph about how what not to post
and how the work is still on progress
.....

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Is nobody going to comment on these?

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Setting the stage here....?

a good way to particle up the athmosphere in your room is heating some glycerine, or so I read.
Take pictures with the camera positioned opposite the laser, so it's coming at the camera,
but not directly, at an angle of course. From slightly below for example.

Use a camera where you can control exposure time and aperture, close the aperture
somewhat good and expose for few seconds.

The spiro, only fast and slow, no pot?
The liquid sky, wow what a huge mass of mirror to spin around.:na:

Also, ditch the 9V batteries.

I don't get the 3 position switches for the spyro. IMO half the fun is finding all the different combinations with complete control of the speed of the motor. Other than that they look good. I would also add some laser warning stickers.

in order to get the'wispy' efx in L.S. be sure to cut off anything that moves the air(ie a/c ceiling fans etc) a bunch of incense sticks just below the beamage works pretty good- a tripod is a must. Also using the smallest room you have (like the bathroom) will concentrate the fog/smoke. the camera angle make a big diff. too.... from behind the lasers or just above or below(in line with the axis) give the best results. your boxes look good. Why not build the tunnel efx- just as easy as the LS. PM me or corner me at LC if I can help.


hak

I would replace the three position switches with pot's so you get more patterens and better control of them.

Whats that buzzing sound you playin with the bees again :crackup:

I'll organise the comments into categories to respond to them. Makes it easier for all of us

anselm said:

a good way to particle up the athmosphere in your room is heating some glycerine, or so I read.
Take pictures with the camera positioned opposite the laser, so it's coming at the camera,
but not directly, at an angle of course. From slightly below for example.

Use a camera where you can control exposure time and aperture, close the aperture
somewhat good and expose for few seconds.

Click to expand...

hakzaw1 said:

in order to get the'wispy' efx in L.S. be sure to cut off anything that moves the air(ie a/c ceiling fans etc) a bunch of incense sticks just below the beamage works pretty good- a tripod is a must. Also using the smallest room you have (like the bathroom) will concentrate the fog/smoke. the camera angle make a big diff. too.... from behind the lasers or just above or below(in line with the axis) give the best results.

Click to expand...

I don't have air conditioning or ceiling fans. I tried using a glycerine\water fogger, a disposable smoke aerosol (which for some reason smells a lot like cinnamon) and some matches one after another and still couldn't get it right. A problem with the fog was that it remained wispy and fluid-like for a bit before diffusing evenly throughout the air (which is what you need it to do for most laser effects... so I guess the problem was that it was working as desired ). There was a similar problem was with the aerosol, although it did stick around for a bit longer it was also being propelled further so while it stayed non-diffused it was forming a jet and not spreading gradually. The match smoke stayed tight and did produce the right effect, but was too localised and travelled upwards instead of downwards so it only had an effect for a short while before it had risen above where the laser was. Incense seems like a good solution as it's localised smoke which continues to be emitted across a long period, I might have to go seek some out.

I spoke to my dad, showing him the pictures I'd taken and he had a go and he could pinpoint what the problem was. It's that in order to get enough light in to produce the effect, either the area needs to be lit up or flashed in which case the laser can't be seen or the exposure time needs to be lengthened in which case it doesn't produce the effect I built it for because the smoke has moved before the end of the picture so it ends up generating solid a wall of light instead of a liquid "flowing" one.

anselm said:

The spiro, only fast and slow, no pot?
The liquid sky, wow what a huge mass of mirror to spin around.:na:

Also, ditch the 9V batteries.

Click to expand...

Flaminpyro said:

I would replace the three position switches with pot's so you get more patterens and better control of them.

Whats that buzzing sound you playin with the bees again :crackup:

Click to expand...

Kevlar said:

I don't get the 3 position switches for the spyro. IMO half the fun is finding all the different combinations with complete control of the speed of the motor. Other than that they look good. I would also add some laser warning stickers.

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I explained about the use of binary speed control instead of pots in my essay. The issue with potentiometers is that you have to search for patterns you like. That's part of the fun, sure. But this runs on batteries, so that would need to be done every time it was turned on because as the batteries drained they would supply fewer Volts so the motors would be driven progressively slower.

@anselm: Not sure what you mean about the Liquid Sky. Are you commenting on how I mounted it the mirror to the motor? Also, regarding the 9V battery, I did also use 2x AAs but that only supplied 3V and the motor didn't spin fast enough. Although it did make an interesting effect, appearing like the laser line was flashing on and off.

@Flaminpyro: Nah, the noise is the motors. It's a pretty loud machine which is something I will work on if I decide to implement any improvements. If you listen carefully you can hear us talking about it. At one point I ask him to slow down because the motors retain some momentum when you change speed so take a bit of time to settle into the new speed. One of the disadvantages to using one of the hobby motors rather than a cooling fan.

@Kevlar: The spirograph has one just above the aperture window. I've been meaning to add one to the LSP. I did calculations on power density and determined that in both cases provided you're a metre away an accidental direct exposure shouldn't do any harm, but at the same time the motors and lasers are turned on by different switches so it is possible to output a static dot. Therefore, yes, I will be attaching a laser safety sticker.

hakzaw1 said:

your boxes look good. Why not build the tunnel efx- just as easy as the LS. PM me or corner me at LC if I can help.

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I know how to make the tunnel effect. I could have made it separately, but I didn't really see the point because the spirograph can produce that effect anyway. But thanks for the suggestion!

Thanks guys! And keep the questions and suggestions coming!

Most (PC)fans only run in one direction and are not easy to have unlimited rpms both fast,stop, slow and in between , which limits your possibilities. Wispy works best for Tunnel and LS. diffused is better for seeing beams especially from the side.

I use a fog machine but when in a hurry I just use my bathroom and a dozen sticks of incense. keep trying.


len

I did consider using PC cooling fans. The advantages being that they're very quiet and that they're spring-loaded so they respond to speed changes almost instantly. The disadvantages being what you stated, price, and the fact that my school didn't stock any so I'd have had to pay for them myself

The incense will produce a much more wispy sort of smoke, right? I will try that as soon as I find some. My only worry would be my asthma, but I'll do it in the kitchen or something so I can quickly get all the smoke out using fans and a back door. Haha... i'm excited!

Worth noting it's perfectly visible to the eye and the effect comes out fine when you look at it, it's just capturing it on camera. Also, the video does not do the spirograph justice because of the way that the camera doesn't do persistence of vision in the same way as us.

Getting good photo's of lasers can be tricky, however there is 1 thing you will definitely need for good photo's, a tripod (Or a solid surface)

Set the camera down on the tripod or solid surface, and put it into shutter speed mode. First, you'll want to set it to manual focus. With the lights in the room on (And before you let the fog out), focus the camera on the spiro box itself.

Next, change the camera to ISO 400 or lower, this will reduce the graininess of your images (In trade for lower brightness), and set your long exposure to say, 1 second.

Fog up the room enough to see the beams (But not too much, or you'll just overexpose it and get a wash of laser), turn out the lights, and go back to the camera.

Make sure it's rock solid on it's tripod or stable surface, then without touching the camera, quickly press the shutter button and move your hand off it as quickly as possible. Since you are doing a long exposure, even the slightest movement of the camera will ruin the image.

If the image turns out too bright, keep turning down the exposure speed bit by bit until it looks good, or it only starts capturing part of the liquid sky.

then without touching the camera, quickly press the shutter button and move your hand off it as quickly as possible.

Click to expand...

I kinda find it better to keep the finger on the button as long as the shutter is open,
so you won't jerk the camera as you pull the finger.

Find this. Or something like it, also check out lazeerers thread about DIY fog.
It works just as good as a fog machine or incense, and a $4 bottle will last you 5 years more than likely. I bought this bottle the first month I joined, october/November, and one or two drops will suffice. See I've barely used any!



Also, with this stuff, no smoke, no smell, no asthma inducing, no nothing like incense or real smoke would do. You wouldn't even know it was there if you closed your eyes. This stuff is amazing, just a few drops, heat it up, let it make your laser beams ever so elegant

I have a smoke machine, which will suffice most of the time. I just needed something for the liquid spirograph which wouldn't disperse evenly.

I may try the glycerin when I get bored though.