A Mostly 3D Printed Escapement Mechanism

"A Mostly 3D Printed Escapement Mechanism" is a model I've wanted to design for quite a few years. Having no experience whatsoever in horology, I finally decided to step up and design my first windup escapement mechanism.

As usual I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to ask as I do make plenty of mistakes.

Designed using Autodesk Fusion 360, sliced using Ultimaker Cura 4.12.1, and 3D printed in PLA on Ultimaker S5s.

1. Thick cyanoacrylate glue.

I acquired the following parts:

1. One Metal Spring (see the attached "Obtaining The Metal Spring" video ).
2. Three 4mm ID, 12mm OD, 4mm thick ball bearings.
3. Twelve M4 washers.
4. One M4 lock washer.
5. One M4 by 8mm button head cap screw.
6. One M4 by 10mm button head cap screw.
7. Four M4 by 25mm button head cap screws.

I 3D printed the following parts at .15mm layer height, 20% infill and no supports:

1. One "Anchor.stl".
2. One "Balance Wheel.stl".
3. One "Base.stl".
4. Two "Bolt (M8 by 1.25 by 22mm).stl".
5. One "Escapement Wheel.stl".
6. Two "Foot.stl".
7. One "Gear, Pawl (1.5m 32t).stl".
8. One "Hair Spring.stl".
9. One "Pawl.stl".
10. One "Spring Housing Cover.stl".
11. One "Spring Housing.stl".
12. One "Spring Mount.stl" (if you wish to use the metal spring).
13. One "Spring.stl" (if you wish to not use the metal spring).

This mechanism is a high precision print and assembly using at times very small precision parts in confined spaces with highly precise alignment. Prior to assembly, I test fitted and trimmed, filed, drilled, sanded, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on your slicer, printer, printer settings and the colors you chose, more or less trimming, filing, drilling, reaming and/or sanding may be required to successfully recreate this model. I carefully filed all edges that contacted the build plate to make absolutely certain that all build plate "ooze" is removed and that all edges are smooth using small jewelers files and plenty of patience.

This mechanism also uses threaded assembly, so I used M8 by 1.25 and M4 by .7 taps, and M8 by 1.25 die as required for thread cleaning, and an M4 (4mm diameter) ream for bushing hole cleaning.

To obtain the metal spring, I performed the steps shown in the attached video.

To assemble the spring motor, I performed the steps shown in the attached video.

Assembly notes:

1. Instead of using the metal spring and "Spring Mount.stl", you may substitute "Spring.stl" with a reduced run time.
2. Prior to assembly, I used an M4 by .7 tap to clean the threads in "Pawl.stl", "Spring Mount.stl" (or "Spring.stl") and "Knob.stl".
3. I used small dots of glue as a "thread lock" between cap screw threads and 3D printed threads.
4. I glued two "Foot.stl" to the legs on "Spring Housing Cover.stl".

To assemble the escapement, I performed the steps shown in the attached video.

Assembly notes:

1. Prior to assembly, I used M8 by by 1.25 and M4 by .7 taps to clean the threads in "Base.stl"
2. Prior to assembly, I used an M4 ream to clean the bushing holes in "Hairspring.stl", "Anchor.stl" and "Escapement Wheel.stl".
3. I used the 25mm long cap screws for attaching the hairsping and balance wheel, anchor, and escape wheel to the base, and for the knob axle.
4. I used the 10mm long cap screw for attaching the pawl gear to the pawl.
5. I used the 8mm long cap screw for attaching the hair spring to the base.
6. I used small dots of glue as a "thread lock" between cap screw threads and 3D printed threads.

For final assembly, I performed the steps shown in the attached video.

And that is how I 3D printed and assembled "A Mostly 3D Printed Escapement Mechanism".

I hope you enjoyed it!