We all know the problem when you've been to the toilet for some big business. While washing your hands you think: 'just air-freshner is not enough! There should be a way to warn innocent visitors to stay away from this place for a little while.'
This biohazard warning is the solution for this global problem.
Just set the timer for the hazard you left and in time the warning scale will turn to 'safe' again.
It is an easy and cheap build. The only thing I bought for this project is a cooking timer. I mostly used trash materials and scraps.
Step 1: You will need
- packaging (trash) cups
- cooking timer
- something to use as backboard
- hobby knife
- tools to create the backboard
Step 2: Disassemble the cooking timer
This is a really easy step; Just take the timer apart until you are left with just the (still working) inner mechanics.
Step 3: Prepare the inner cup
To make the housing I used two desert cups that fit inside each other (for the Dutch: Monatoetje voor de binnenkant en AH-tomaten emmertje voor de buitenkant)
First mark where to cut the bottom from the inner cup. The easy way to do this is holding a sharpy on the inner part of the timer and then move the cup around against it. You will end up with a perfect marking (as long as you didn't move the sharpy)
Use a hobby knife (x-acto or Stanley or something) to cut off the bottom from the cup. Always use sharp tools and be careful not to cut yourself or someone else.
If you use a sharp knife it will be very easy to cut along the line that you have drawn on the cup.
For my timer I needed to make a few holes in the bottom of the cup to mount it on the timer. You can also use just glue or a screw or whatever. This will be different for different cups or timers.