have Rube Goldberg type activity using a Marble Machine to allow students to design and create their solution to a problem. Bernie Zubrowski’s book on balls and ramps was the original inspiration for developing Marble Machines and i got this from a MOOC, Coursera's course "tinkering -motion-mechanisms" (other ideas in the MOOC "tinkering -circuits" is also worth checking out). [I urge any teacher of STEM, STEAM or technology & design to go to the MOOCs at https://www.coursera.org/ and find all the resources in the 2 courses mentioned]
I pre-cut and drilled the timber and used grade 5 & 6 students to build them, for use with students from grade 2 to 6. The students use dowel pegs tape or hooks to connect various objects to direct a marble in a zig zag motion to slow the marble down and get it from (A) at the top to (B) at the bottom.