Road grader used to level off rocks on a roadway, improving the drainage, filling in large holes, and widening it.

Grader – a construction machine with a long blade used to create a flat surface during the grading process. Typical models have three axles, with the engine and cab situated above the rear axles at one end of the vehicle and a third axle at the front end of the vehicle, with the blade in between. Also commonly referred to as a road grader, a blade, a maintainer, or a motor grader

What’s the problem?

  • Ask – There are many places where people want a large flat or smooth surface, for roads or building sites. In winter, removing deep snow from roadways is essential. How can this be done by machine? What does the machine need to be able to do?
  • Imagine – The general process requires some dirt and rocks to be scraped away. Some of that material can be used to fill in holes and build up low spots. How would you make a flat surface using a shovel? How could this be mechanized and made really big?
  • Plan, Create – Depending on the planned use of the grader, these machines usually must travel long distances – to be economical to level large open spaces or miles of roadways. How can a grader move itself and the material it is leveling? How many different conditions must be handled?
  • Improve – How can the basic grader be improved to be more efficient?

That’s engineering

  • blade, toe, heel
  • wheel lean

Learn more…

  • Grader (video 3:41) – song, description