Busy Hands

Howdy Folks,
I've been getting my students to make stuff.  The first project we did was making egg cars that had to withstand running into a brick wall.  Exciting if you are an egg.  Not too exciting if you are a worldly 14 year old though.  They got to test a car, come up with new ideas, see the buzz in the automotive industry, check out each other's ideas (steal?) and give it another go with a fresh egg. It truly is difficult to tell what is going on inside their heads.  Even with the most modern educational pedagogy, checking for understanding, testing, quizzing, and asking them, "Hey, what's going on?" its hard to tell.  I know for myself, very few ideas make their home inside my head after the first visit.  And alot of the time I've got to sit with an idea for years before it becomes part of my bag of tricks.  Honestly. 
It takes real patience and perserverance in order to teach even a new dog a new trick.  So after the cars, we built bridges.  And after the bridges we are going to build earthquake safe buildings.  And after that we are going to build electronic buzzers based on the capacitors and resistors.  And after that we'll make buzzers with the 555 timer chips.  Then after that we are going to build Arduino bots. 
Get the picture?  I need to keep their hands busy making stuff and their minds busy making stuff work.