Expert: Martin Meyer - 9/2/2009

Question
Hi Martin.

I bought a wall clock for 7,5€ in some kind of secondhand store, on the case it says "eurobell" and on a plate on top "tempus fugit(time flies)" the movment is from FHS model 241-030 and is made in 1981 and 88.80 is what i think is the swings the pendelum makes a min. but how can you tell the pendlum makes 88.80 swings, is there someway or method for this?

This clock whas filthy but i mean really filthy, i came home and hung it to the wall to test it, swinged the pendelum... nothing no ticking noise, toke the movment out and on the gears was a hard kind of filth, removed it with a cocktail stick, hung it up again and there it was a lovely ticking noise, this was the reason the store sold the clock for only 7,5€ what do you think this clock is worth in good condition?

On the pendulum bob there are some brown spots is there a way to get rid of them?

Greetz Hubert

Answer
Hi Hubert,

This movement is made by Hermle (FHS = Franz Hermle Sohns). Beneath the stamping "241-030" should be two numbers separated by a horizontal line. The number above the line is the pendulum length. The number below is the beat rate in Beats Per Minute. Given the number you state, your pendulum is probably a 55cm. My information gives a beat rate of 88.183 for this pendulum length, but Hermle makes minor changes from time to time. Clockmakers convert this number into Beats Per Hour, then use a timing machine which counts the ticks and calculates the beats per hour in a few seconds.

Without a timing machine, you can get a rough idea of the beat rate by using a stop watch. You will probably want to stick with beats per minute, as you will probably not want to have to count to over 5,000 and spend an hour doing it. This method will only give you an approximate rate, which will be useful only if your clock is very far off its correct rate. Note that "beats" are Ticks; so if your pendulum swings to the left, then back to the right, the clock makes two ticks and that is a count of two beats. Accurate adjustment is better achieved simply by keeping track of the clock's timekeeping over a period of a couple weeks, and making periodic small adjustments to the pendulum regulating nut to correct it.

I would not be too optimistic about the clock's continuing to run when it is that extremely dirty. If the clock stops again and will not run anymore, you may need to consider a cleaning or cleaning and overhaul. This is absolutely not something I would recommend that you do yourself; it requires special, and very toxic, solutions, and any general purpose cleaning solutions will almost certainly either not help or actually damage your clock.

Brown spots on the pendulum bob are usually places where the lacquer has come off the pendulum. If your pendulum is lacquered, only complete stripping of the lacquer and subsequent polishing of the bob will correct the situation. If the pendulum is not lacquered, you can probably polish out the spots, although there may be remaining corrosion in the brass itself underneath the spots, which cannot be removed. Once the lacquer is stripped, of course, the pendulum will tarnish and will need to be periodically polished.

As I indicate in my profile, I answer clock repair and service questions only. I do not do appraisals or valuation.  http://www.clockmasteronline.com