THE 9 DOT PUZZLE
Here's the solution...
4 lines connecting all 9 dots... as long as you're willing to go outside the box!
At MechaniCraft, we think outside the box in order to provide you with the most practical and reliable solutions.
If it can be done with a paperclip and two shoelaces, maybe it should be... If it cannot, we'll be happy to build you a machine.