Steal This Deal From Puzzlemasters!Tumbler Designer Jon Keegan is a graduate student at The University Of Oklahoma enrolled in the Gallogly College Of Aerospace And Mechanical Engineering. His puzzle story started in 2014 when he purchased his first puzzle from Wil Strijbosthe highly popular Aluminum Cross. In 2017-18 he enrolled in a series of Design and Manufacturing Process courses at University where his first puzzle idea came to fruition&lsquoThe Tumbler&rsquoMaterials: 6061 AluminumBall BearingsClassification: Mechanical Take-Apart