Instructables
Picture of Automatic Laser Spirograph (No programming)
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In this instructable I will show you how to make a laser spirograph that changes forms automatically, and without the need to program an Audrino. This is accomplish by the use of 3 almost identical circuits that controls the 3 electric motors.
 
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Step 1: How it works

Picture of How it works
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     As you can see in the picture there is one circuit board with the tree individual circuits, three motors (two computer fans and a normal motor) with mirrors attached, and a green laser pointer. I use a laser that has a switch instead of a button, so I can leave it on while I enjoy the show.

     Like I already pointed out, in each motor there is a circular mirror. These mirrors are from disposable dental mirrors, because they are already rounded, have a nice size and are easy to work with. The mirrors are glued in a coaxial way with the motor, but they have a small tilt. When the laser strikes the spinning surface of the tilt mirror, it is reflected forming a circle. If this circle is projected into another spinning tilt mirror it will form a variety of shapes, depending on the motors velocity and other factors. Adding a third motor just opens the possibility to even more complex shapes.

     If you want to see it in a more scientific way, the resulting shape is the plot on polar coordinates of the following equation: f(r,ø) = A sen (x* ø) + B sen (y* ø) + C sen (z* ø). Were “A”, “B” and “C” are the amplitude that is the mean of how much the mirror is tilt, and “x”, “y” and “z” are the velocity of each motor and the offset between them.

    So to be able to change the shape that is plotted you need to change the amplitude, the offset or the velocity. I can’t think of a simple way to change the amplitude, you couldn’t control the offset unless you used stepped motors and that is out of my reach. So what I did was to change the velocity of each motor.
rapbone1025 days ago
thanks much appreciated
rapbone1025 days ago
im using a 12 volt 1amp dc adapter i connected the power i blew up my ne555 chip sorry to be pain
fado1986 (author)  rapbone1025 days ago

Ok, several things. First: The 555 can work with up to 16v, so I dont think your adapter blew it. Second: I said that the only way this circuit could work is by using a desktop computer power supply because you need +5v, -5v, +12v, -12v and ground (you need all of them!!!). And third: the 555 can only source up to 200ma to the fans/motors, so if the motors consume a greater amp you´r gona blew the 555. Hope this helped.

rapbone1027 days ago
im confused with two pins which goes to the motor im really bad in electronics
pls help
fado1986 (author)  rapbone1027 days ago

In step #3 I said: "The motors are connected to each NE555 output (Pin #3) and ground." Hope this help

rapbone1029 days ago
hi could you please help me out with circuit bord im not able to make it work
fado1986 (author)  rapbone1028 days ago

Hi: Whats the problem that you are having? Have you tried to narrow it down?

amir0266 months ago

hello sir

I can't find voltage of capacitor and there are kind of capacitor with different voltage , please tell me about their voltage that use it in this circuit .

fado1986 (author)  amir0266 months ago

Hi. If you see the power supply, the max voltage I used is 12v. So the min voltage for the capacitors are 12v, but I used 24v or higher.

Thanks for you comment.

boempa1 year ago
Hi again.
I was wondering: would it be possible to make a photo of the back of the board, so that I can check all the connections compared to what I have soldered?
Thanks!
boempa1 year ago
I'll look into buying an oscilloscope someday, sounds really usefull.
However, for the time being, I'll just mess around a bit and figure out some electronics. Thanks for the tip.
boempa1 year ago
Thanks!
I misjudged the grounds, whereas I thought the ground + and ground - of the TL082 went to the motors, however now I understand that one end of the motor is connected to the TL082 and the other is connected to the NE555, that cleared things up for me.

Hopefully I will now be able to complete the project :)
Thanks again for the help!
PS: I have a simple digital multimeter, with a beep-sound indicating positing to simply check if a connection is good and nothing gets short-circuited.
PS2: somehow I can't reply, but have to type a new comment, because otherwise it gives an error of typing the 2 words.
fado1986 (author)  boempa1 year ago
It dosent matter that you have to post a comment every single time. Im here to help ; )
If you are into electronics you should think in buying a good multimeter (Im a noob and I have 3 different kinds, jajaja). And when you get a little bit more serious you should buy a oscilloscope. There are some fearly cheap on ebay that you plug to the computer with USB and works really nice.
boempa1 year ago
Many thanks for replying so soon!
I encountered a problem, what I was afraid of, as being new to electronics.
From what I can tell, all connections are good, I get the + and - 12 and 5v power.
No shortcircuits.
I assumed that the TL082 grounds go to the motors (+ and -), but perhaps I am confused there?
My multimeter says all connections are okay, but the grounds - and + don't have a signal.
Should I apply the +12v and -12 from the power in and loop it to the motors?

Thanks in advance.
fado1986 (author)  boempa1 year ago
I dont understand what you mean with your last sentence, but any how... Are you making your readings with a digital or analog multimeters? Sometimes digital multimeters cant give a reading with some frequencies.
You are correct, the motor goes between the output of the 555 and the ground of the TL082. Also, you have to use the ground of the power supply to the ground of the TL082. If you can get your hands on a osciloscope it would be great. Hope this helped.
boempa1 year ago
Many thanks for your awesome instructable!
I'm gonna make a special birthday party for my mother in law who's gonna be 50 soon.
Besides music, I'd love to do something cool with a laser pointer, and came across this build.
I thought I'd give it a go, but my knowledge is very limited towards electronics.
Now, I figured out where to solder all the resistors and capacitors, and the 5v and 12 + and -.
However, I didn't figure out what lead to solder from the TL082 to the NE555 and what the 'fork' symbol stands for (couldn't find it on google, but my guess is it has to do with the 3 circuits connecting each other?).
I'd be very gratefull for any help, and it'd be awesome to get this working.
Thanks in advance!
fado1986 (author)  boempa1 year ago
Hi: thanks so much for your comment, Im so glad you are gonna give it a try.
The fork symbol is ground, and if you see the out signal from the TL082 it is a red "saw", and in the 555 circuit there is a equal red "saw" connected to the voltage control (leg #5). Thats how you connect together the two circuits.
One important point is that you may think that a 12v or 5v supply has in one side + and in the other - and thats not true for this circuit. If you put a tester between the +5v and -5v you are gona measure 10v, and in the case of 12v you are gonna measure 24v. So be clear, the measure of voltage the disgn has is between the supply and ground. I used and very old PC power supply, they usually have the color code in a sticker in one side.
I hope you can build this and have a great time with it, and that your mother in law enjoys it too. Just one final though, for a better result I used a 5mw laser. You can use a normal laser but the room have to be really dark (all lights out).
Very cool toy! Thanks for sharing.
fado1986 (author)  paganwonder1 year ago
Thanks for your comment. And you are welcome! I enjoy sharing my creations.
rimar20001 year ago
Buena idea, y bien construido.
fado1986 (author)  rimar20001 year ago
Gracias. No entré mucho en detalle, pero si se sabe de electrónica no debe ser muy complicado de hacer. ;)