Expert: Michael Radi - 12/4/2008

Question
I have a Hermle movement 451-053H/85cm that doesn't run free when the escapement is removed. It seems to be frozen, although I can spin the escapement gear wheel manually, and it runs freely. I removed the escapement because it seems stripped free of the section the attaches to the pendulum.  thx very much

Answer
It can be difficult to troubleshoot where the gear train is binding. It could be worn out. You can check the pivot holes where the gear shafts go into the brass plates. There is a pivot hole on each plate for every gear. With the weight off, push the chain gear both directions and watch the pivot holes. If you get pivots that move excessively, the hole is worn and this could cause the movement to bind up.
Another thing to check is the chime and strike. The movement has to lift levers as it runs. Be sure that the chime and strike run all the way through their cycles and stop, then try the escapement again.

The last thing to check is to be sure that nothing is bent. A bend hand shaft will stop a clock. Turn the minute hand forward and see if the escapement starts up. If the hand shaft is bent, the escapement will be free for a little while and then stop as the shaft advances. You may also have a bent pivot. Look inside the escape wheel pivot hole as the wheel turns. If the pivot is bent you can see it rotate out of round.
I hope this helps.
Michael