Help in building a Spirograph

[lonewolf7978]

I’m interested in build a spirograph. I have basic skills in building circuits. I’m looking for help with the motor controller and laser pulse circuit. I’m thinking about using a 317 voltage regulator and a pot to adjust the speed of the motors and a 555 timer to pulse the laser. Am I on the right track?
Any feedback would be great.
Thanks

 

[chipdouglas]

you might not want to pulse the laser.... you would probably get better results by using 3 motors with variable speed capability... Hobby Shack sells 4 packs of small motors for about 7 bucks.

michael

 

[lonewolf7978]

Why not pulse the laser?

 

[chipdouglas]

i don't know to be honest.... never seen it done. you get great shapes with 3 motors.

michael

 

[lonewolf7978]

3 motors seems to be the trend and looks great for the ones I seen on here.

 

[Solonar]

Unless you are trying to do something like WhiteFusion, pulsing a single laser will just get you dots or dashes, not really a spirograph.

I suppose you could have 3 pot controlled motors and also adjust PRF and Pulse width of the laser to create some odd patterns though.

 

[lonewolf7978]

For the motor control would you use a 317 voltage regulator with pot or would you lean toward an Arduino to control the motors?

 

[goninanbl00d]

Or you could just hard-wired potentiometers.

That's what everyone does, and it works.

 

[lonewolf7978]

would motors or fans would be best?

 

[goninanbl00d]

Motors are a better idea.

 

[lonewolf7978]

Plain DC motor is that what you are talking about?

 

[goninanbl00d]

Plan DC hobby motors that you can buy just about anywhere.

They'll be just fine.

 

[Kevlar]

Have you seen this thread yet? Its a very good tutorial for whay I think your looking for.

http://laserpointerforums.com/f51/tutorial-four-motor-compact-laser-spirograph-51363.html

 

[Things]

Using just potentiometers is a risk, because if one of your motors gets jammed, it may draw more power and fry your pot.

Using a voltage regulator like the LM317 wastes a lot of heat. You don't need a whole microcontroller (Arduino) to run a spiro, though you can if you want to add pattern presets, sound reactivity etc. I'd recommend PWM'ing the motors. Much more accurate.

 

[lonewolf7978]

What do you mean by "I'd recommend PWM'ing the motors."?

 

[Things]

Pulse width modulation. Basically, instead of varying the power to the motor, you just chop it up to make more of an "average" power. Because the motor is inductive, it's speed will adjust according to the PWM. Almost all microcontrollers have PWM outputs. The Arduino has like 5.