Flippe Tops

prusaprinters

This is a new kind of tippe top which flips over and over. On the outside it looks like a sphere, inside is a ball bearing which is free to move up and down in a cylindrical channel. The ball bearing gives the top an uneven weight distribution, leading to its strange behavior. When you spin the top, the ball bearing begins in its lowest position. Because this is a tippe top, as it spins it wants to invert (flip over) so that its center of gravity is above the center of rotation. But when this happens, the ball bearing drops down (listen for this) and the cycle repeats. It is not difficult to obtain 5-8 flips of this top as it slows down, as shown in the videos. Because it is a sphere it is not obvious when this top flips over. It is printed in two halves, I recommend using two contrasting colors so the flips are evident. It comes in three sizes, and I suggest printing the small size first. You will need to purchase a 3/8" diameter ball bearing for the small size top. Ask in a hardware store if they sell single ball bearings. Print Settings Printer Brand: Prusa Printer: i3 MK3 Rafts: No Supports: No Resolution: 0.15 mm Infill: 15% Filament: Hatchback PLA Notes: After you print two halves in different colors, insert a ball-bearing into the channel. Each size takes a different size ball bearing. See the README file.rnrnThe easy option is to glue together the two halves with superglue. The second option is to use metal alignment pins, as described in the README file. The advantage of the second option is that the top can be taken apart. You can mix and match halves.rnrnNOTE: If you aren't using pins, be EXTRA CAREFUL to align the two halves when gluing. If this alignment is off the ball bearing can get stuck in the middle, and the top won't work.rnrn11/29/2019: I uploaded new files with larger holes so the alignment doesn't have to be perfect. How I Designed This =================== A large number of prototypes were printed to get this flipping behavior. Feel free to experiment! I include an openSCAD file which allows one to vary the parameters of the top. Changing the infill percentage can also significantly change the dynamics. Category: Mechanical Toys