If you have a laser machine i am sure that you already have expermiented a lot of materials, why not coconut shell?
In this tutorial i am going to give you the basis to engrave coconut shells, and turn then into little halloween monsters!
This tutorial is also available in video (sorry for my bad english) if you fancy one :)
Step 1: Step 1: Prepare the Coconuts
If you bought coconut from your local supermarket, you might have to remove the inside (liquid and white stuff).
Try to get a shell as rounded as possible, if you want to have a head-shaped coconut. As you can see mine have been pretty destroyed on the process.
Try to keep some spared pieces that you'll use as scrap to experiment the settings on.
Step 2: Step 2: Make Some Tests
Because every laser machine is different i cannot tell you what are going to be your speed/power settings. The best thing to do is to engrave and cut a little design on your scrap / spared piece of coconut.
During every test, note the settings and choose wich one gives you the best results.
For example I choose to engrave with the same settings than 1/4 inches of plywood ( engraving:P100/S70 ; cut: P100/S0.4)
Step 3: Step 3 : Engrave Your Design
One you've got all the settings ready you can start engraving.
Try to set the focus on the higer point of your coconut shell. Because it is a rounded shape you might have issues on the focus on the edges.
Try to place to part of the coconut you want to engrave on the top and as flat as you can. Use somme bits of wood to you need to. Do not place anything underneath that can caught fire, the laser can get thought and set fire to your set up.
Step 4: Step 4 : Cut the Eyes and Place Some Lights
If you decided that you wanted to cut your coconut, repeat the previous step but with cuting rather than engraving.
Cutting a coconut shell is quite smoky and firery so be carefull.
The edges of the cut might be a bit more difficult to cut because of the defocus to do not hesitate to go throught 2 ot 3 times, or even push with your hand if part of eyes have not been cut thought.
To set light on your coconut, i would recommend some led light powered with battery, just put it on the back of the coconut shell and let the spooky begin!