The Retrograde Mechanism
The Retrograde Mechanism
Published 2020-05-18T11:41:10+00:00
The Retrograde Mechanism is found in most mid to high end mechanical watches where the pointer only sweeps through small angle instead of a full revolution. The pointer jumps back to its initial position after making a full angle sweep. This is a simplified version made 3D printable to illusrate how it works.
Assembly Video: https://youtu.be/1HozfIwFNjo
Links to the hardwares that i used:
1.5mm and 2.0mm pins (I used ejector pin shafts that is cut down to length using a dremel with diamond disc cutter)
https://www.aliexpress.com/item/32915349219.html?spm=a2g0s.9042311.0.0.4a8a4c4dJPLrde
M2 Screws
https://www.aliexpress.com/item/32810872544.html?spm=a2g0s.9042311.0.0.3d2e4c4dIpyhiK
Dremel Diamond Disc Cutter
Only the front frame requires support.
Printed on Ender 3 and Prusa Mk3s.
Nozzle Diameter: 0.3mm
All gears and font markers are printed at 0.1mm layer height. outer wall speed should be kept around 15mm/s
The frames and structures are not too critical so it will work with 0.2mm layer height and 0.4mm nozzle.
It is critical for the spring to be printed in PETG as PLA will deform over time and lose its spring effect.
Other hardware:
Ø1.5 x 25mm pin (x3)
Ø1.5 x 13mm pin (x3)
M2x8 screw (x7)
M2x4 screw (x6)
All shaft holes are designed to have a slight tight fit in order to avoid cases of loose shft fitting due to printer to printer variation and slicer settings. Use a 1.5mm drill bit, a burred edge pin or any suitable methods to slightly enlarge the hole to achieve a good transition fit and the gears should rotate freely.
Date published | 18/05/2020 |
Time to do | 10 - 15 minutes |
Material Quantity | 50 |
Dimensions | 100 x 45 x 115 |
Looks so cool any body known what rpm motor is needed to make this a clock I am making a big one 600mm tall