Martin sez, "I just completed my silliest projects to date: while running the risk of turning my laser cutter into a giant fire ball I actually succeeded in turning it into a real world version of the Space Invaders game."
Each Space Invader is held into place with a paper clip, they're cheap, simple to operate and made of metal so they don't burn. The paper clips are wedged into tight fitting slots on the back board, this was only ever going to be used 2-3 times so the friction fit is sufficient. The drive motor has a toothed gear fixed onto it so my only option was to laser cut another toothed gear and use the drive belt. This gear connects to a rack and pinion which drives the space invaders left and right.
Because of the genuine risk of fire with this project I completed a test burn before the main event. This was a bit more controlled in terms of how much I was shooting. It was very useful and mostly told me that my Space Invaders were too close together and that the fire would spread across the row very easily. I redrew them all a little bit smaller to give me more room between Invaders. Fire can still spread, especially if you shoot straight down to the bottom row but this definitely helped reduce the spread.
Space Invaders made real! [Martin Raynsford/Just Add Sharks]