I use my laser mainly to prototype things that I later mill but also to make foam fun objects.

The foam isn’t strong, however, it allows incredibly fast prototyping using the same CAD files that I eventually use with the mill.

The foam also allows fun things to be cut quickly such as a batch of MC Escher’s lizards

Or a nightmarish 3D Escher by Lance Kelly on GrabCad

This looked so simple but it proved incredibly fiddly to actually assemble such that all of the pieces were interlocking

and of course the obligatory pen holder!

A few notes for anyone considering using a laser. (Repeated from the main laser page because I think this is important)

  1. Eye protection – this is not optional! (Don’t forget to get some extra safety glasses in case anyone else wants to watch the laser in action)
  2. These are designed to burn through things so use with great care and use responsibly
  3. These are VERY random when bought on line!
  4. Laser diodes have a short life expectancy

My first laser module was really cheap and produced a beautiful fine round beam. The module had great optics and was easy to focus. Cut through the foam so perfectly.

BUT…. it only lasted a couple of weeks before the power supply died (or so I thought). After a few checks and trying adjusting things, it turned out that the LED was also dead. Whether this failed and killed the power supply or whether I zapped the diode while trying to fix the supply we will never know.

I then bought a similar model but a little more powerful from the same supplier – this time with an external power regulator PCB. The new LED is MUCH more powerful. The result is that it melts the foam. Secondly, the optics are not nearly as good and it makes a wide bar rather than a point. The result is that it can be focused but to an oval dot and this diverges again very rapidly.

The width of the bar at the top can be seen clearly in the photo below so this gives an idea of how much the focussed dot will diverge on the other side again.

Cutting foam therefore tends to produce razor like surface cuts on the foam when moving in the X direction and a wider surface cut when moving in the y direction. Unfortunately the underneath is a different story with a wide melted area.

So why didn’t I just move the laser diode from  the housing with the bad optics to the one with the good optics? I might in the future however it is working and I’m worried that I will have to apply so much pressure to break the glue and remove it that it might not last long after that.