Hermle 170-030 Comitti Mantel Clock Striking Randomly

[SirPecanGum]

I have bought a second hand Comitti mantel clock - it is a lovely little thing - with a Hermle 170-030 movement which, as I understand, is dated "N" or 2001. Unfortunately the hour strikes are random so, for example, at 9 o'clock, the hour may strike 4 times, 5 times, 6 times or indeed, as would be great, 9 times. It does this intermittently on hours 5 o'clock through 12 o'clock. Hours 1 o'clock through 4 o'clock have so far behaved correctly. Assuming I'm right with the age, is it time for a replacement movement or is there something I can do to fix it?

 

[shutterbug]

It sounds like a rack and snail issue. You'll have to get to the front of the movement, and remove the rack (lots of teeth, left side). Clean the post and the hole that it rides in really well, and check for burrs or other surface issues. Put it back on and see how it performs. No oil!
Let us know how it goes.
When you remove the rack, the clock will want to strike. Just put a paper clip or similar on the fan to stop it while you work.

 

[SirPecanGum]

Thank you for taking the time to offer your help. I have removed the face and everything looks clean except for a build up of a black substance between the brass rack and the silver part which the brass rack rests on. I expect its just from contact but I have cleaned it off and wound the clock forward, by the minute hand, for 48 hours without seeing any obvious issues and the strikes have been perfect! Perhaps the black substance provided enough "stick" to interfere? I don't have a tool to remove the sprung washer type fastener on the rack - that may be for someone else to do. I bought the clock knowing I could replace the whole movement. Delighted! Thank you!

 

[Willie X]

The problem will probably repeat, unless you take the steps outlined by Bugs. The little clip can be easily removed and replaced using most any type of pliers. Just keep you finger on that clip, so it can't go flying across the room. You can work inside a clear plastic bag to help prevent loosing the clip, if you like, photo added. Willie X

 

[SirPecanGum]

Thank you very much! Your guidance does encourage - if the error repeats I will try. I have some soft jewellery pliers that shouldn't leave any tool marks.

 

[Willie X]

Steel pliers are fine. No need to worry about any "marks". Willie X

 

[shutterbug]

I agree with Willie - it may well happen again if you don't really clean it up. I use a very small screw driver to remove the clip. Keeping a thumb on it helps prevent loss It will go back on with a little pressure, and that's the procedure that for me loses the most clips.
It does seem that the rack is your problem though, and that's encouraging.