Best way to repair giant wheel spring holder?

Bernie Murphy

Registered User
Sep 30, 2012
23
0
1
Ottawa
Country
Region
Attached is a picture of the giant wheel for a Waterbury clock. The pin that holds the mainspring has worn down. It could tap the pin out a bit farther and file or should the pin be replaced ? I don’t have any pins but I assume a nail would work. How far out should the pin extend to catch the spring? My guess would be about 2.5 mm?

DACF3373-01BB-4D3E-8EFD-5AA6026B39B7.jpeg
 

bangster

Moderator
Staff member
NAWCC Member
Jan 1, 2005
19,940
459
83
utah
Country
Region
If you can tap the pin out, it needs to be far enough out to snag the spring. Use your judgment.'A bit too far won't hurt anything. Undercut it with a file to form the hook.
If you can't tap it out, drill the arbor and replace it. The steel in a nail is plenty hard enough to work.
 

R. Croswell

Registered User
Apr 4, 2006
10,919
1,080
113
Trappe, Md.
www.greenfieldclockshop.com
Country
Region
Attached is a picture of the giant wheel for a Waterbury clock. The pin that holds the mainspring has worn down. It could tap the pin out a bit farther and file or should the pin be replaced ? I don’t have any pins but I assume a nail would work. How far out should the pin extend to catch the spring? My guess would be about 2.5 mm?

View attachment 641668
Bernie, are you actually having a problem with the pin not hooking the spring? It is quite common to find that the pin was holding the spring OK until the spring was removed for cleaning but after reinstalling the pin won't hook the spring. Two often overlooked problems are; 1) the inner spring coil is often expanded and/or distorted during removal and no longer forms tightly around the arbor, and 2) the second coil layer is tight against the inner coil thus preventing the pin from passing completely through the hole and hooking. Extending the pin will not help much if there is no space between the 1st and 2nd coils. Extending the pin may help hook the spring if the inner coil is too loose if you can keep it hooked until it is fully wound but there is the possibility that it could slip off before a full wind "tightens" the inner coil.

'Not withstanding the above, if the pin is worn down and/or the leading edge is rounded off, it should be reshaped, and extended or replaced.

RC,
 

Bernie Murphy

Registered User
Sep 30, 2012
23
0
1
Ottawa
Country
Region
Bernie, are you actually having a problem with the pin not hooking the spring? It is quite common to find that the pin was holding the spring OK until the spring was removed for cleaning but after reinstalling the pin won't hook the spring. Two often overlooked problems are; 1) the inner spring coil is often expanded and/or distorted during removal and no longer forms tightly around the arbor, and 2) the second coil layer is tight against the inner coil thus preventing the pin from passing completely through the hole and hooking. Extending the pin will not help much if there is no space between the 1st and 2nd coils. Extending the pin may help hook the spring if the inner coil is too loose if you can keep it hooked until it is fully wound but there is the possibility that it could slip off before a full wind "tightens" the inner coil.

'Not withstanding the above, if the pin is worn down and/or the leading edge is rounded off, it should be reshaped, and extended or replaced.

RC,
Thank you for the tips. It turned out that the original main spring’s last 1/2 inch broke off. Also, the giant wheel pin that catches the main spring was worn down. I had ordered a new main spring before starting the repair so I used it. The original spring was tired but could have been used again in a pinch.

I drilled out the worn down pin in the giant wheel using the drill press and held the wheel in a small vice attached to the drill press table.

I needed a replacement 3/16 pin and tried using a 3/16 drill bit. That drill bit steel is super hard! Bad idea! So, I took a 2 inch finishing nail and made a pin using an electric drill as a primitive lathe and tapered the pin about 3 thousands using a metal file held against the spinning nail in the drill. Tapped the new pin into the wheel shaft and finished up by using a bench grinder to tidy up the job.

The repaired clock should be good to go for another 60 years...
 
Last edited:

Forum statistics

Threads
164,793
Messages
1,433,862
Members
85,803
Latest member
Chas99
Encyclopedia Pages
1,101
Total wiki contributions
2,863
Last edit
Rockford's early high grade movements by Greg Frauenhoff