DIY laser spirograph (part 1)

Motorized mirror assembly.

Since laser spirograph is not intended to be precise optical instrument, any available reflective material may be used as a mirror.
I know some folks have experimented with regular glass round mirrors, dental mirrors, hard drive plates and built decent working devices.
CD/DVD media may be used as mirror too but because of data tracks CD acts like diffraction grate and splits bright laser beam into few weak beams.

DVD as a mirror. It may work as a temporary solution. 

DIY laser spirograph (intro)

Simple laser show everyone can build.

DIY laser spirograph.  Cool and affordable laser show.

According to Wikipedia, spirograph is a geometric drawing toy that produces mathematical curves known as hypotrochoids  and epitrochoids.
Yes, it sounds like quite complicated scientific apparatus and, believe me, mathematical equations describing those curves look terrifying too, but it's a wonderful toy so if we leave boring science behind we'll learn that it's quite easy to build one and it's a real fun to play with.

LCD backlight repair

How to repair LCD backlight.

LCD backlight failure is most common cause that gadget ends up its useful life on a scrap yard.
In reality, this problem can be easily fixed by replacing faulty CCFL lamp or (and that is much more interesting) by making new light source using modern super bright LEDs.

DIY LCD backlight repair.

Technique described below can be applied to repair or modify any kind of LCD.

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