3D Printing - Expanding on initial projects

Above: Design shown from above

Challenge: Once students have mastered the concept of producing basic designs and ideas how can they move onto more challenging designs and prints.
Background: This student has shown an aptitude in design and creation, so we have been encouraging her by giving her the lattitude and opportunity to create larger designs with differing purpose.   This design reflected that, for while it appears to be another straight copy of the badge design, using scribble to create the picture, which in essence it is, the student created a significant rectangular lip or frame around the outside of the design.  This had the affect of allowing the design to independently stand on its edge, and balance it.    The student had been using Dash and Dot Robots, as part of a task to code and was looking to expand on something to integrate with that.  Once this design was completed and created the student was using it conjunction with the robot, and had the idea to create a series of targes for the robot to be coded to come into contact with.  The student is intending to colour code the targets, with different point values/phrases for the robots based around the difficulty to get them. 

The same thing could also be created as a target systyem for a form of rocket launcher or technology challenge, as the 3D Printer could easily target a class set of targets or students could develop their own game as a result.  The pieces being 3D Printed are extremely durable, well made and virtually indestructable. 
Degree of Diffculty: Low/Medium - the dimensions etc just determined by the purpose.  You can always spray paint the PLA when finished or actually print it out as different colours.
Timeframe: Six and a half hours - this is not suitable as a badge etc due to its increased dimensions, having said that for the School PE Shed we did exactly this on purpose three years ago (its too big for the students or the staff to easily put the key into their pocket, hence they tend to return it to the location where its suppossed to be,
You could reduce the idea of targets to something smaller but we want to be able to hit them.
What we would do differently next steps for the students: This was produced with a hole in the top right hand corner we would remove this as it serves no purpose.