I am continuing work on my Dugena mantel clock with a Hermle movement. Everything seemed to go well after re-assembly but the strike barrel.
A serious problem or simple fix? The latter, thankfully. Something was definitely amiss since the winding arbor was not engaging on the mainspring. The spring was either broken or had not engaged the winding arbor sleeve.
I had no choice but to open up the barrel but it was not much fun getting the cap off. Some suggestions I received on a clock forum site were to bang the arbor with a steel hammer or a rubber hammer and it would pop neatly into my hand. This did not work. Finally someone suggested that if it was really stubborn to find a piece of hardwood, hold the barrel in a gloved hand and bang it with some amount of force on the hardwood. It worked!
Once I got the thing apart I inspected the spring and arbour for possible damage. I initially thought the spring catch (see photo with black arrow) was broken but a member of NAWCC (National Association of Watch and Clock Collectors) assured me that this was quite normal. I re-positioned the catch onto the spring, tested it and snapped the cap back on.
The barrel can be easily slid back into the clock without taking the movement apart. Using the clock key I gave it a few turns, tested the action of the strike side and everything seemed to be working.
Now for bench testing. I put a make-shift hour hand for the clock to see if it marked the hours properly. Testing for a week or so will reveal any issues and allows for finer adjustments before I install the movement back into its case. Everything looks good at this point.
The original problem was that the clock was running too fast and no amount of adjusting would slow it down. I am hoping now that after a good cleaning it will run as it should.