Printable opto-switch flags for Prusa build

These are printable opto-switch flags for use on the Prusa Mendel. The X and Z flags mount on existing hardware. The Y flag needs holes in the beds bottom plate to be mounted.

Y and Z flags are set to fit M3 screws and the X flag M4 screws.

I've found that no matter how finely printed ABS nor PLA will block the light from the LED. To fix this I used a small piece of electrical (insulating) tape to cover the end of the flag. I figure most people will have a roll of electrical tape around an