I had been meaning to return to the Daniels Double Escapement for a while. Here it is spinning merrily away at 4rpm/14400bph:
In my view, it is the most aesthetically pleasing watch escapement. As described previously:
"...This is a model watch escapement based on a design by George Daniels based on the natural escapement concept by Breguet as ingeniously utilized by Derek Pratt (I could go on). It couples the benefits of the Swiss lever with those of the detent escapement while attempting to eliminate each designs' weaknesses. Of course the potential added efficiency and accuracy is almost wholly negated by the added mechanical complexity. Even so, I find its visual symmetry coupled with its intentionally asymmetric tick more appealing. The latter quality necessitates a...."
...remontoir. to decouple the escape wheels from each other as the carriage rotates. The alternative is to have two separate power trains as George Daniels did in his watches, but that is difficult to incorporate into a tourbillon, so I stuck with the remontoirs. This time around because it is hand powered, I eliminated the forks.
I originally intended to power this design off of a weighted ball chain, but this escapement requires much more power. This is somewhat counterintuitive since it relies on radial thrust rather than sliding action as in the Swiss Lever. The greater mass of the carriage, the inertial of two escape wheels, and the double unlocking action, however, more than make up for the energy saved. In an actual watch, that may not be the case especially if there are two power trains independently driving each escape wheel. I may adapt the hub piece to incorporate the spring motor I designed for my Dual Ulysse model.
- All shafts are 2mm
- Requires one 608 bearing (22x8x7)
- Print two of the spokes part and print two escape wheels (one mirrored)
- The pallets (both impulse and locking) are slightly oversized and must be sanded down to perfect fit.
- The top frame kind of looks like some sort of Satanic goat head emblem
- Add grub screws to the balance wheel to calibrate
Balance wheel at 95%, the rest at 30%.
Printed in Printrbot natural PLA and Hatchbox green PLA on my Reach 3D printer (it's been halfway around the world with me and still going strong!)
I was able to print everything on two plates. The prints came out very well requiring me to only ream out shaft holes and sand pallets. The tolerances are a bit looser on this design, so I'd still feel confident printing it on a lower quality printer.
Largest part is 83mm diameter, so it should work on even small format printers.