Flying Tourbillon

This is a spring-driven, one minute tourbillon designed to amuse and annoy in equal measure.

Print instructions

This is a simple model of a Swiss lever flying tourbillon as found in many high-end watches.

Vocabulary lesson:

Tourbillion - A feature designed by Breguet as a method to counter gravitational errors on the balance spring and improve watch accuracy. By rotating the spring as part of the tourbillon cage, any induced error averages out. There is still debate as to whether the tourbillon improves accuracy or only serves to increase the complexity (and price) of mechanical watches.

"Flying" - Cantilevered off of only one pivot rather than requiring a bridge. I suppose "flying" sounds more dramatic and sells more watches than "cantilevered."

Swiss lever - The most ubiquitous mechanical watch escapement mechanism in the world. It was originally invented by Thomas Mudge. Its simplicity and ability to self-start account for its popularity despite its less-than-ideal efficiency due to the sliding friction off of its pallets.

This is a modification of my initial design (https://thingiverse.com/thing:1991251) powered by six quarters attached to a #3 ball chain. I figured the spring would be more user friendly and would allow this design to work as a kind of horological fidget spinner.

BOM:

All printed parts.

Non-3D printed parts are the following:

1 x 608 bearing

2 x 2mm diameter 20mm long steel shaft or a straightened PLA strip

1 x 2mm diameter 22mm long steel shaft or a straightened PLA strip

grub screws to adjust the timing

blue tape (if required)

Printing notes:

All files can be modified in Openscad or your favorite 3D modelling software to customize shaft and bearing hole sizes.

I printed everything in the photos on my Reach 3D printer, but I have made working versions with my Prusa i3 MK3 and Monoprice Mini Delta as well. That being said, my CAD designs require better than 200 micron accuracy to prevent binding.

Using filament strips rather than steel shafts generally will yield a workable (though far less efficient) design. For instance I can usually get over one minute of run time with the metal shafts, but the filament strips version will only run for about 40-50 seconds. This is because the narrower shaft diameter and flex, some of the energy must be spent pushing the escape wheel and anchor back into position with each tick.

Assembly (see photos):

1) Fit shafts into spring, anchor, and escape wheel ensuring minimal friction.

2) Press fit the bearing into the base piece.

3) Stack together spring, balance wheel, and roller (note orientation in photos and exploded renderings).

4) Pin balance spring into matching slot in frame a using a spare length of filament and PVA glue if desired.

5) Arrange escape wheel and anchor as shown

6) Insert frame b into bearing wrapping shaft with blue tape if necessary to ensure a snug fit.

7) Press fit the 60T annular gear onto the matching hex pegs on the base piece.

8) Press frame a into frame b ensuring all shaft holes match.

9) Press mainspring onto the exposed hex shaft on the bottom of frame b

10) Wind spring so that it engages the ratchet teeth

11) Allow self to be mesmerized at its spinning

12) (If sufficiently persnickety) Add grub screws to holes in the balance wheel and tighten/loosen until it ticks at 2Hz/14400bph.