Internet Horology Club 185
Removing Gears

This topic can be found at:
https://ihc185.infopop.cc/eve/forums/a/tpc/f/6346047761/m/1911035013

May 10, 2008, 05:05
John Croudy
Removing Gears
Hi, I'm a beginner at clock repair and I've been learning a lot by making some pretty nasty mistakes. I recently worked on a Smiths movement and now I'm working on a Hermle striking clock. In both cases I've had the same problem -- I can't figure out how to remove all of the gears. The easy ones fall out when I separate the plates, but there are always a few difficult ones left; in particular the centre arbor which holds the hands. I've attached a picture of the problem gear. It would be great if someone could explain the procedure for taking this off. With the Smiths clock I just left it on and worked around it, but this time I can't get the springs out unless I remove the centre gear. Thanks in advance for any help.


May 11, 2008, 20:04
Tom Chaudoir
Hi John,

To remove that gear you really need a special tool to pull the 4 lobed cam off. Once it's off you will probably find that there is no wear and so you wasted your time. The lion's share of the force is applied at the other end of the arbor. That's the pivot most likely to wear of the two. I usually leave it on and let the ultrasonic do it's job, then make sure to get a small drop of oil in there. That might sound slipshod, but even with the special puller you risk damage to the cam.

To remove the spring barrels, just grab the winding arbors and pull them out. If they resist tap the other end with a light brass hammer while pulling. Caveat: This is only true for Hermle and other movements with removable arbor inserts.

The other 2 gears that are giving you fits are the ones that carry the cams for chime and strike. Those can and must be removed. If you pry with a screwdriver or something, you will bend the arbors. You need to pry from both sides at once. If you like to spend money, there are fancy tools for that. If not you can make them.

Start with a couple of plain old bottle openers. Grind off the pointy end so it doesn't stick you later. The bottle cap end makes a nifty cam pulling lever. A bit of grinding to reduce the thickness will make it easier to get the pullers under the cams. Use both tools at once. Put a couple layers of tape around them at the fulcrum point where they will rock against the plate to keep them from scratching it.

Hope that helps.
Best,
Tom
May 12, 2008, 15:58
John Croudy
Hi Tom,

Many thanks for your interesting reply. I had no idea that spring arbors could be removed without taking the springs out. My biggest problem at my current level of experience is not knowing the right way to do things. Should I try to force something off or would it break? Mainly for that reason I do like buying the right tools and I might do that at some point, but for now I think your bottle opener idea might do the trick for the strike cams.

Thanks again for the advice.

John
May 15, 2008, 04:59
Bill Marker
Hello John
I recommend that you read the web pages of [URL=http://www.abbeyclockclinic.com He has many how to pages of useful information for the beginner and seasoned repair person. Great info with great pictures too.Cheers bill@fixoclox
May 18, 2008, 17:20
John Croudy
Thanks Bill. Your link didn't work but I was able to find the site as abbeyclock.com

John