Continue Robin remontoire - August 2009

This month B. continues to fabricate the Robin remontoire. Below is B.'s drawing for the Robin remontoire escapement. Notice the style mimics that of the Harrison escapements - that is of a rooster's comb and beak. Another demonstration of consistency of design that we keep throughout the project. Next photo shows the raw stainless steel 1/4 " stock from which the escapement will be cut.

The thick and harder steel as compared to brass precluded the use of the jeweler's saw that B uses for most flat stock. A nibbler machine was used to rough cut the 'C' shape of the escapement frame. Later this is smoothed with hand files. The forth photo shows the pivoting pallet head which comprises the coup perdu design. This is necessary as we want have a one minute release for the Robin remontoire, but the release from the Wagner remontoire which is to drive this sub system is once every 30 seconds. Completed escapement assembly is next and last photo shows the escapement in place within the movement.

Below is a diagram in connection with the detent release for the Robin remontoire which will drive the celestial train. B. had designed a four lobed cam to be introduced between the detent and the celestial train release lever so as to allow the detent and thus the fly to be released every minute. The one minute release was in the original specs but during the course of the project was deemed too impractical to implement because the signal for the release is derived from the going train remontoire cycle which is every 30 seconds. The idea was to have the Robin fly actuate at a different cycle than that of the Wagner remontoire cycle and to activate during the quiescent time for the Wagner flies. The original specs called for the Robin fly to release at differing intervals so as to achieve a 'surprise' in relation to the regular periods of the Wagner remontoire mediating the time train. By having the period of release of this fly differing from that of the time train I wanted to add to the overall interest holding the viewer's attention. This fly is to be deep inside the movement to give the viewer the impression of a caged butterfly.  Below B.'s design achieves this on a regular one minute basis with his four lobed cam. It was not long before I determined that an irregular cam could achieve this one minute interval with a time frame of five to ten seconds on either side. In this way the fly will still be released during the quiescent period, but it can vary close to and then in the middle of those periods. This allows the fly to achieve a true 'surprise' to the viewer as the cam will vary the release by six differing intervals.

Once again B. continues to work on a problem to give the customer what he wants. He overcame the issue of the signal being sent every 30 seconds to achieve a one minute interval. With collaboration we were able to extend this to a one minute irregular intervals.

First photo shows the ratchet wheel which will power the Robin remontoire and the six lobed cam that will control the fly release. At this time the cam has a regular profile, but after installation and testing will be cut by hand through trial and error to achieve the irregular intervals as discussed above. Next five photos show the fabrication of the detent wheel that will follow the cam profile and control the the timing of the Robin remontoire fly fan release. The frame profile is shaped by hand filing, second photo, the follower wheel is jeweled, third photo, the fork holding the wheel held with guide pins and a screw, fifth photo, and the finished part, connected to the Robin escapement, last photo. In a conventional design there might have been a pin sliding against the surface of the cam. In this project all such applications are met with a jeweled wheel.

The first photo shows completed detent wheel is shown installed within the movement and mated to the Robin cam. It seats perfectly. Next two photos are of the complete Robin system along with a couple wheels of the celestial train with  front and rear views before installation into the main movement. I think I can say this is the most complicated Robin remontoire arrangement ever conceived. Can we make this project more fabulous.. of course we can!

Now begins the fabrication of the system that will connect the Wagner remontoire, which drives the time train, to the Robin remontoire which drives the celestial train. The first three photos are of the ratchet pawl that will hold the ratchet wheel steady while it is being pushed by the linkage to the Wagner remontoire. The bottom three photos show the parts of that linkage that will connect to that ratchet to push the wheel.  The forth photo is a part connected to the Wagner and is an eccentric configuration; very much like the control linkages on the antique steam locomotive engines that one can see near the track wheels. This is connected to a rod upon which the the other end a pusher wheel is connected and is shown in the last two photos. In essence, the ratchet wheel is being 'pumped' by the Wagner remontoire as it turns.

These photos show both ends of the celestial drive linkage linkage. First the part connected to the Wagner. It moves back and forth as the wheel it is connected to turns one full revolution. At the other end of the rod is connected the pusher wheel that pumps the ratchet wheel forward to wind the Robin remontoire.

The Robin remontoire system now installed into the main movement. Second photo from the rear. Notice the two right-most going barrels, (time and celestial trains), have their ratchets installed and are now under full power (they will eventually have a pair of pawls each set at 1/2 tooth to give a doubling of the winding sound when wound). This same 1/2 tooth design is used on all the fly fan arrangements to enhance the audible effects.

B. now fabricates the lead slugs that will fit with the decorative brass weight shells. The lead is first cast as rough lead disks and then machined to fit perfectly within the brass cylinders.

The first video to the left shows the movement completion to date. the second, a Utube video shows a longer clip of the Robin remontoire's drive wheel being pumped from the time train's Wagner remontoire. Also shown is the recoil pawl to keep the drive wheel in place as the pump arm is being retracted. As can be seen from the clip, more adjustment is necessary on this part.

                                       Astro_08-09_vid.mpg