Jappy Freres Motion Work Setting marks

[Candix]

Hi all again,

There is something that has puzzled me for a long time - When I set the motion work on any clock I do it the old conventional way.
However when it come to antique French (Jappy Freres) clock movements, I notice that all three motion work wheels have pop marks for set up.
The canon pinion is popped between teeth, the minute wheel also popped between teeth, and the hour wheel is popped on a tooth. Just can't see how this all works for setting up using the popped marks. Once the hour wheel is slipped on it covers both minute and canon marks. Both the canon and minute wheels can't line up as the pop marks are between teeth.
Does any one know just how all this supposed to work. I have included pictures.
Regards candix

 

[David S]

Just finished one. Here are the pics I took.



Now as a double check make sure that the rack tail clears the 12 o'clock to 1 o'clock rise on the snail.

David

 

[shutterbug]

It doesn't look critical to me, but as long as they are there, you might as well use them. Perhaps because the snail doesn't have steps, it makes it easier to set things up.

 

[Candix]

Just finished one. Here are the pics I took.

View attachment 472285 View attachment 472286

Now as a double check make sure that the rack tail clears the 12 o'clock to 1 o'clock rise on the snail.

David

Hi David,
Thanks so much - I have always set these up the old traditional way, without any problems, I have always wondered just how these pop marks were to work. It all seemed illogical.
I notice that the POP mark on the minute wheel on yours is right on the tooth where the one I have here is between teeth as is the canon pinion which further confused the issue.
Thanks for all the trouble you went to for me, much appreciated.
Regards candix