FHF70 balance jewels settings

Bonefixer · May 3

Latest project was a non-running ebay purchase with an FHF70 movement. I stripped and cleaned it, reassembled it, and got it running. So far so good, nothing damaged AFAIK.
I was oiling the top jewel on the balance (the one in the cock) which was a slightly unusual shock setting. I removed the spring (3 leaves) which was part of a chaton holding the cap jewel. This left the hole jewel behind which I retrieved with rodico and then lost it. I was taking it off the rodico, very gently as I thought, with tweezers, and then it just disappeared.
Fast forward a week, I got a donor movement, non-running, with the plan to just take the shock jewel that I’d lost. It was the same movement but had standard incabloc settings, and was steel rather than copper/brass.
I changed the cock and balance complete and it ran, not very well. I switched the lower jewel setting, cleaned and oiled both jewels and the replacement balance. Without the pallet fork the balance swings very nicely with a puff of air. With the fork in place, balance out, it flicks side to side nicely with power in the mainspring.
Put them together and it doesn’t run. The impulse jewel sits in the fork and it stops.

Any suggestions how I proceed? In case you didn’t follow that I have 2 FHF70 movements, nothing broken as far as I can tell, but mixing up the balance wheels and jewel settings results in a non runner.

GuyMontag · May 4

It looks like this movement comes with a number of different shock settings. Emmywatch shows that it comes in versions with no shock settings, 'Incabloc', 'shock resist', and 'Supershock'. Perhaps the different settings position the impulse jewel/roller table in a non-ideal position relative to the pallet fork/guard pin. Are you able to check under high magnification if the pallet fork and roller table are able to operate without any interference?

Just for fun I took a look and I have one FHF 70 in my collection, a West End Secundus with a non-shock protected FHF70. I had a note with the watch that said, "Movement is stamped 'FHF 70', but the FHF70 looks to have sub-seconds instead of center seconds movement (??)" but that a google search turned up both types for this movement.

EDIT: I just took a look in my parts drawer and I have a few of these movements, both in center seconds and sweep seconds, but they all are non-shock protected.