Sotwa with FHF 59-21: A tiny movement that is a joy to work on

 This one was easy and straightfoward except for rust in the escape wheel's pinion leaves. The dial was in a bad state too and it seems that either there was no lacquer or it was completely damaged because the standard cleanup of water, a qtip and rolling gently removed some letters. Kinda disappointing but a lesson learned.

  

On the timegrapher, before service. Not too bad but it is obvious something was wrong here. Pretty sure it was the rust in the escape wheel's pinion wheels.

 

Small but mighty.

The escape wheel before and after, huge difference after polishing with dialux and a pointy stick.

Timegrapher results. Before

Position	Rate	Amplitude	Beat Error
DU	234	324	5.9	?????
DD	337	177	4.1
CR	448	335	5.8	?????
CD	502	289	7.1	?????
CU	429	123	4.9
Delta	268
Mean	343.2	184.8	4.38

And after.

Position	Rate	Amplitude	Beat Error
DU	19	283	0
DD	2	310	0.1
CR	-4	269	0.2
CD	5	283	0.2
CU	-3	279	0.1
Delta	23
Mean	0	228.2	0.12

Quite the improvement. Quite some difference between DU and DD and I suspect it is a problem with the escape wheel not having been replaced. But it was good practice and got respectable results after manually polishing between the pinion leaves of such a tiny wheel.

Overall happy with this one, except I wish I didn't touch the dial. I've also been enjoying working on FHF movements, they're well built and easy to service.