3D Printed Key Ring

Challenge: To introduce new students to basic 3D Printing and design we wanted to introduce some new students (aged ten and eleven years old) to 3D Printing.  To do so we were looking to identify a short term project complete that would engage the students.   We went for designing a working key ring, variations of which we'd attempted before.
Background: We have attempted this before in the past but wanted to look at it again to complete it in a short turn around.   The idea was originally for a keyring however it is noted at our school that junior students have ID tags for equipment etc and this would also sort it as a possible use for this item.   The 'Oliva' tag shown in red in the photograph was designed by a student

who was eight years old, and featured a triangle deisgn next to the name.  Both of these are available on the basic Tinkercad interfact and can be accessed and used within and extremely short time frame.   The second basic example that is shown, the yellow print with the name 'Lexi' also included a basic dog shape, was designed and created by a ten year old student.
Level of Difficulty: Low - the students are using the basic interface as an introduction.   The tags shown are basic designs from the interface that students who are as young as seven or eight can complete easily.  With assistance it could be completed conceivably by younger students.
Timeframe: One hour - the design was created with this in purpose.  We were looking at ways to produce something that would have a purpose in a short space of time.  There would be the opportunity to alter this by reducing the size of the base, which has been printed with a 20mm width.
Size: We were using the same basic starter block for this print - a 70mm by 20mm with a width of 20mm.   This proved to be satisfcatory for this print, and this could be modified to mass produce them, we also looked at only just modifying the keyring by changing PLA over and could have looked at producing a series of component parts to produce multiple colours. 
What we would do differently: Nothing from the design for this print, we have attempted to complete the project and done so succesfully.
Next Steps for Students: Having completed this project the students concerned are using it as an introduction to moving onto more challenging projects.