Hi, there is contests at Instructable.com about Tinkercad. All you have to do is a create and post a project at Instructable about Tinkercad 3D Design, Electronics, Arduino or Blocks. It is great contest for teachers. Because teachers like me use Tinkercad to teach 3D design, electronics, Arduino, coding and blocks. So I create a project on Tinkercad.com and post it to Instructable for contest.
Contest started at 15 August and closes October 10th. Instructable.com offer 24 PRIZES to attendants. Grand prize is 500$ Amazon gift card. Time flies, anyone can create project with Tinkercad and post it to contest. Hope you will enjoy it.