Removing a clock mainspring barrel
Removing a clock mainspring barrel
Often a clock mainspring barrel can be taken out without disassembling the clock movements outer plates, on Hermle or Kieninger clock movements. The mainspring will also still stay inside the barrel.
Letting down the mainspring power
The mainspring let down tool allows the release of the mainspring with the fist rather than the fingers.
Put the mainspring let down tool over the square post the key goes onto. With a flat screwdriver, move the click out of the way.
The click has a tension spring that needs to be held back. This is what holds the mainspring so that it winds in only one direction. Slowly allow the mainspring to unwind in the fist.
This method lets the control the speed of the unwind with the whole fist rather than the fingers. Unquestionably, doing this with a key will result in a painful experience on the fingers.
Of course, if the mainspring is broken, there usually is no worry since there isn't much tension to begin with.
After the barrel is out
Once the power has been let down, the next step is to yank out the winding arbor shaft. The clock mainspring barrel should then fall out the side of the movement. After the barrel comes out, you can see the number that is on the barrel end cap.
Be sure to check the movement for any damage as a result of the mainspring breaking. In particular, inspect the teeth of the gears, as well as the arbor on the next wheel up. This could have consequently been bent.
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It is a Hermle 1050 movement, the click spring is f shaped and fits into two holes in the plate.
Yes the F part is stamped into the front plate.
If the unit is 20 years or more old, get the new one. These are 25 year units at best and the impact of the mainspring breaking most likely caused damage to the next gear and pinion up the train.
Please order the 1050-020 from this link
https://www.clockworks.com/product/new-1050-020-clock-movement-by-hermle
James Stoudenmire
40yr Clockmaker
Author of Clockworks.com
How does the click spring come out, and the new one installed, mine broke when the main spring broke and let loose.
Yank it out with pliers, it is stamped in there. Not easy to replace, do not have that part alone to offer, best to get the new unit.
James Stoudenmire
40yr Clockmaker
Author of Clockworks.com
Can I remove the chime spring barrel on a Kieninger RWS24 without separating side plates.
If I remember right, the answer is yes. Be sure there is no power to the spring first.
James Stoudenmire
40yr Clockmaker
Author of Clockworks.com
Thank you – I’ll try and tap it out
Hello, super article. You say “yank out the winding arbor shaft”. I am meeting great resistance to manage this on an HAC clock. It does not look as if I need to separate the plates. Can you advise please?
Not sure what HAC clock style would be. These notes are primarily on the discussion of post 1950 German units instead of prior.
More on clock movement identification
https://www.clockworks.com/clock-movement.html
More on hole end mainsprings
https://www.clockworks.com/product/hole-end-clock-mainspring
Thank you for answering.
I have a Ridgeway clock, spring driven, mechanism marked only “Gravely Furn Co Inc; Martinsville VA/USA; Made in Germany; No (0) Jewels; Unadjusted; n=4390.” There is a serial number at the bottom center “370081.” I need a new mainspring w/barrel. I have the barrel out of the clock, and there are no markings whatsoever on it. The rear cover plate (lid) has a “u” shaped hole on one edge. Barrel is 44.55mm outer (teeth) dia, barrel 39.89mm dia, drum depth 21.31mm, and shaft height from front to back 33mm. Drum has 60 teeth. I can’t find anything that matches this on google. May have been serviced, as there is scratched above makers marks “SITS; 5326; 9-89” Can you help me?
Hi
We would need the movement numbers off of the movement itself please
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