Here is a full unit of work. I delivered this over 7 weeks, with a whole Wednesday dedicated to an Engineer each week. At the end, we had the pupils create their own STEM museum for the whole school to come and view.

The day largely followed this model:

Play with K’nex/Blocks
Maths
Outdoor Game
Literacy (Podcasts)
Art
Lunch followed by another Game/STEM challenge
20 min speed write
Ethics Debate
Minecraft Models (using Redstone)