This is a mechanical watch with tourbillon driven by a 3d-printed mainspring. The watch has a Swiss lever escapement. The mainspring inside the going barrel keeps the watch running for approximately 30-45 Minutes. Accuracy is roughly one Second deviation within one Minute (depending on print-settings).
The project demonstrates that the 3D-printing technology is developing. Compared with earlier generations of 3d-printers, the process works more reliable and more accurately. However it's still a very advanced project, because printing inaccuracies need to be trimmed manually with some watchmaker skills, or the watch won't tick.
The watch is designed with Autodesk Fusion 360, and printed with Ultimaker 2.
How it's made:
https://jig.space/view?jig=728 (Thanks to http://www.thingiverse.com/greenlig)
Assembly Time Lapse:
Autodesk Fusion 360 Design:
http://a360.co/1S4wp4W (all parts assembled)
http://a360.co/1KUNz3g (main spring relaxed)
Many thanks to Nicholas Manousos for his great article in HODINKEE explaining the importance of my project from a watchmakers perspective. His first 3d-printed Tourbillon 1000% was also a source of inspiration for my work.
0.4 mm Nozzle
Only the Pawl Unlock Key needs to be printed with support.
Hairspring, Anchor, Escapement Wheel, and some gears were printed with high resolution (0.06mm layer, 0.8mm shell). All other parts are printed with normal resolution (0.1mm layer, 0.8mm shell).
The infill of the anchor is 80% in order to have a better balanced center of gravity (rest has 30% infill).
For the case I used PETG (slightly bendable, shock absorbing), and the gears are printed with PLA (harder and less friction). In colors: black and yellow parts are PETG, orange and red parts are PLA.
The Mainspring is printed with PETG (PLA probably breaks after a while). I switched off "combing" in Cura. While this is a cool feature for regular shaped parts, it causes problems with large spiral shaped parts: The print-head does many useless long (2 meters!) travelling moves. Printing not only takes 30% longer, it oozes during the move, and when continuing to print, the nozzle is empty of material, and the resulting under-extrusion is disastrous.
The Hairspring needs to be printed in PLA. Other material basically work as well, but due to different stiffness, it's expected, that the watch runs too slow, or too fast. The design of the spring needs to be changed depending on the material.
Printing on heated glass-bed. Used a mix of alcohol and water to clean it. Adhesion is exceptional. For removing the parts from the build plate I poured a few drops of the same alcohol mix into the groove between plastique and glass. The effect is miraculous and the part can be removed immediately without applying any force.
Make sure x- and y-axis of your printer are adjusted really square! My Ultimaker wasn't fabricated good enough (1-2mm slant) - the result were oval Minutes and Hours wheel, and they jammed at some angles.
Watch this video, if you like to understand, how the watch is constructed.
These are all the Parts needed. 51 downloadable and printable, and some Pins and Screws.
- 1 Pin, Diameter 1.5 mm, Length 55.5 mm (tourbillon axis)
- 1 Pin, Diameter 1.5 mm, Length 12 mm (anchor axis)
- 1 Pin, Diameter 1.5 mm, Length 8.5 mm (planet gear axis)
- 3 Pins, Diameter 2 mm, Length 57 mm (axis for pinions for minutes and hours wheel)
- 6 Pins, Diameter 2 mm, Length 22 mm (axis for basic transmission)
- 1 Pin, Diameter 2 mm, Length 15 mm (attachment main spring)
- 1 Pin, Diameter 3 mm, Length 22.5 mm (axis for main spring)
1 Pin, Diameter 3 mm, Length 31 mm (axis for main pinion)
- 3 Washers, Diameter 3 mm (main spring, pinion)
- 6 Washers, Diameter 2 mm (transmission)
5 Washers, Diameter 1.5 mm (tourbillon, escapement)
- 5 Screws, Diameter 1.8 mm, Length 6.5 mm (ratchet pawls)
- 5 Screws, Diameter 1.5 mm, Length 5 mm (going barrel)
- 4 Screws, Diameter 1.5 mm, Length 10 mm (base plate)
- 4 Screws, Diameter 1.8 mm, Length 12 mm (clock face)
- 3 Screws, Diameter 1.5 mm, Length 10 mm (tourbillon cage)
Small holes are usually not very accurately printed. Use a drill to smooth the inner surface - especially the Balance Wheel needs to rotate with very little friction, and very little play. If you don't find pins or screws with the recommended diameter, you can certainly use little larger pieces - there is some "meet" which can be drilled out.
Spring Barrel Assembly: Align the Barrel like in the picture below. It will then slide into the case like in the video (2:49). The Pawl Unlock Key is also a useful tool to keep the pawls in place during this assembly step.
Besides the Winding Key there is also a Key to unlock the Ratchet Pawls. I recommend to fully unwind/relax the Main Spring, when the watch is not used. It certainly will extend the life-time.