Ladies Waltham reburbishment calendar mechanism question.

[Hirst]

Hello WRT Talkers,

I'm still pretty new to this hobby but trying to complete my sixth watch rebuild.  This Waltham ladies is about nickle size and is an auto wind with date.  It's been a very challenging movement to work on due the size and my first calendar mechanism.  I got the movement all together after cleaning and oiling the watch keeps great time and the case and band cleaned up great.  My problem is with the calendar.  I can get the date to change perfectly with the crown in the setting position, but leave the watch running and just about 11:50 the movement stops.  I believe is just the hands that stop.  I recall that there was no friction at all in removing the cannon pinion. I see the cannon pinion is attached to a wheel that drives the date change mechanism 'brass with six spokes under the pinon',  the hour wheel is seated over both..  My  theory is that the it takes very little friction to drive the hands and the connected calendar wheels.  But  the load of the spring that holds the date wheel in place need more friction from the cannon pinion to make the date change. So without the power to more the mechanism, it just stops.  On the movement image without the date wheel the cannon is viable and one can see how it is working with the date works and motion works.  There is a small black spring loaded stop arm that must release to the next date.  Could this be a loose cannon pinon issue? Is a cannon always a friction fit? To my recollection the wheel below the pinion and pinion are one.  Is this a common design for watch movements?  Should I carefully tighten the cannon pinion until I can detect friction to the center pivot?  Adjust in place of use a small mandrel of sorts?

 

Thanks in advance.

[jdm]

1 hour ago, Hirst said:

I believe is just the hands that stop.

You need to confirm if that's the case.

 

1 hour ago, Hirst said:

Is a cannon always a friction fit?

Yes, a slight friction.

 

1 hour ago, Hirst said:

Adjust in place of use a small mandrel of sorts?

Remove the cannon pinion and carefully tighten it in a pin vise. To decrease friction do the same, but when fitted on the center wheel.

 

[Hirst]

2 hours ago, jdm said:

You need to confirm if that's the case.

 

Yes, a slight friction.

 

Remove the cannon pinion and carefully tighten it in a pin vise. To decrease friction do the same, but when fitted on the center wheel.

 

Now I have confirmed that the movement keeps functioning as the minute and hour hands freeze near the 12:00 pm arc.   The hands stay in motion in the 12:00 arc.  I’m leaning toward adjusting the cannon piñon.

[watchweasol]

Hi All indications lead to the fact that the friction on the canon pinion is in sufficient and the extra weight put on it with the calendar change over just proves too much. To tighten the canon first place it on a mandrel and work in small adjustments,  its too easy to over do it making work for your self.  be careful. 

[Hirst]

I keep learning that digesting these problems before trying solutions is the best course.  So here are the new findings.  The center arbor on this movement is just the seconds hand arbor and is not designed to supply power to the hands.  Instead,  a brass center wheel on the face side is powered by a small pinon from wheel 3, shown in the photo with a small arc.

The cannon pinon is a snap fit to this wheel with three brass prongs.  Currently the cannon moves fairly loosely without detectable friction in this wheel. Finally the hour wheel makes the connection pictured right to the keyless works and the calendar works.  For the calendar,  The brass hour wheel turns the small silver wheel, then the larger brass wheel 'left'  which has a single cog to advance the date.  I have shown the underside of the center wheel/ cannon attachment.  Can this be adjusted for friction?  My idea was to use a small tapered punch,  gently tap to expand the steel ring held by brass fingers.  Does anyone have experience with this.  I'm tempted to reassemble without face and hands and try running again before any adjustment.  To be clear, the image with 3x is the center or power wheel inverted so we can see the friction prongs holding the cannon pinon.  I'm confounded by the extra complexity of this movement is just adding a date function. As of now I think that the friction from the brass prongs supply the power to the motion works and the calendar works.  Am I on the right track here?  I feel crazy trying to figure this all out.

Some crazy engineering!

Thanks,

Ron

[jdm]

21 hours ago, Hirst said:

The center arbor on this movement is just the seconds hand arbor and is not designed to supply power to the hands.

Like any other sweep seconds (trotteouse) mov.t

 

21 hours ago, Hirst said:

Can this be adjusted for friction?

No. You have to close down the cannon pinion, with the precautions mentioned above,

 

21 hours ago, Hirst said:

Some crazy engineering!

Seems pretty normal. And it doesn't seem to have a quick-set. Maybe going back and forth around 12 does it.