DIY engineering

portfolio of my projects - electronics and traditional

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DIY laser show from discarded electronics

This laser is built purely from electronics junk I’ve found, and my Basic Stamp 2 I had laying around for quite some time, so it has costed me nothing!
The laser diode is from a recordable DVD player, not sure how strong it is but since it can handle 3 Volts at 240 mA it must be atleast x16, don’t have the means to determine the power of the laser but can safely asume it’s a Class IIIb and should not be taken lightly, the direct beam into your eye can damage your retina!
The collimator is from an old laser printer that I stripped long ago, it has great cooling in it’s housing which is needed.
The casing is made from the scrap metal of the DVD and wellplast from an IKEA box, the motors are from the DVD as well.

I’ve designed the circuitry myself (not the LD driver), I studied the motor and mirror setup in a cheap laser crab I had. It’s quite simple: the motors are aligned 45 degrees in accordance to the beam, and the first motors mirror is angled 4 degrees and second motors’ about 6 degrees. This is tuned depending on how big a flower you want, mine is about 2 m in diameter from a distance of 4 m.
The BS2 simply runs the motors at random speeds (through an LM358 and small signal PNP), for random seconds. I probably will burn a PIC and put in there later since I need the BS2 for other projects.

RPM VAR Byte ‘random seed for rotation
Idle VAR Word ‘random seed for seconds
RPM = 213
Idle = 11000
RANDOM RPM ‘randomize value in variable for motor 1
PWM 0, RPM, 50 ‘PWM out on pin 0, with random duty (voltage) and cycles (adjusted to the RC in my circuit, 10kOhm + 1uF)
RANDOM RPM ‘randomize value in variable for motor 2
PWM 1, RPM, 50 ‘put it out on pin 1
RANDOM Idle ‘randomize time before changing pattern
PAUSE Idle / 10 ‘pause ms, divide Idle time with 10 to avoid too long periods
GOTO Main ‘and repeat!

The whole build and designing took me about 3 weeks on and off.

  1. pulsed posted this