How to Make the Tops (Onshape Tutorial)

Being the Onshape Master and Engineer that I am, I wanted to create the best possible spinning top. The fundamental principal of a spinning top is the moment of inertia. To keep a top going and going, you need a high concentration of mass far from the axis of rotation. Essentially, I’m looking for the greatest delay between input forces and resulting speed. One way to do that is to increase the amount of mass. Something that is massive, will be slower to respond to forces acting on it. Additionally, increasing the distance from the axis is the equivalent to using a giant lever. If you’re pushing at the end of a lever, and I’m pushing towards the middle, you’ll beat me. (These principals work in reverse too. It will be just as hard to get this top up to speed as it will to get it to stop). Here’s a great animation.

The cylindrical ring is the slowest, which is what I want. The cross section of a cylindrical ring is a rectangle, but for artististry, I went with a circular cross section. It makes it look like it came from the space-age. This resulted in a torus. In Onshape, I created a vertical centerline from the origin in the Z axis, and a circle and stem to hold on to.

sketch1

Then I revolved it, creating two separate parts. To connect these pieces with spokes, I sketched a circle on the Front Plane, and extruded up to the face of the torus (the only face of the torus, mind you).
Revolve2
  Then I did a circular feature pattern to create the other 3 spokes. Done and done!
CircPattern3
Check it out here
And here is the final product:

IMG_20171002_075408.jpg

 

What do you think? Right? Wrong? Pure poppycock?