03-01-2017, 10:36 AM #1
- Join Date
- Mar 2017
Cord Replacement - wires broken at motor
There is little left of the wires on this 1934 Hammond clock. I need advice on making a safe and lasting repair.
03-01-2017, 10:39 AM #2
Re: Cord Replacement - wires broken at motor (By: semiretiredman)
I never liked how they originally wired those things. To make a good repair, you'll have to carefully get back to the coil wires, make a connection with new wires, and secure it all again. I think they originally just used electrical tape to wrap around the coil after connection to keep things secure. I can't offer a better way, but wish I could!A man with a clock always knows the time. A man with two clocks is never sure.
03-01-2017, 11:12 AM #3
- Join Date
- Dec 2011
- Brockville, On Canada
Re: Cord Replacement - wires broken at motor (By: shutterbug)
davefr over in the electric forum may be able to give some advice.
03-01-2017, 11:39 PM #4
- Join Date
- Oct 2010
- Calif. USA
Re: Cord Replacement - wires broken at motor (By: David S)
Get the back cover off as best you can. Try to not move the
power wires around. You don't want to stress them at the coil.
Once you have a clear shot at them, cut them from the coil.
Usually there is a lug or something that they are soldered to.
I recommend replacing them with a smaller power cord. Many of the
cords that are used with computer power packs are good.
If the lugs are loose be especially careful. You might even use
a little epoxy to secure them.
Do not try to remove the old soldered wire left from the power
cord. There is no safe way to do this without skills most don't have.
If you break the fine coil wire, it will be a more serious issue.
03-02-2017, 12:26 PM #5
Re: Cord Replacement - wires broken at motor
You do need to be extremely careful because the coil wires are about the thickness of a human hair and will break off very easily if stressed. It's best to do this under magnification.
If all you have left is little stubs of the coil's magnet wire then don't try and solder on a thick power cord. Instead, attach some smaller wire like a 20-24 AWG stranded THHN to the coils magnet wires and then attach the power cord to the THHN. (less stress). You'll need to remove the varnish from the coil's magnet wires in order to solder to them. An Xacto knife will do this but you have to be extremely careful not to break off the wires.
Heat shrink works well to insulate your splices.
You'll likely need to rewrap the core of the coil to secure/insulate the wiring and provide some strain relief. I use 3M #27 glass cloth tape. (don't use common electricians tape).
An even better solution is to slip a piece of large diameter heat shrink over the core of the coil and heat it until it completely compresses around the coil's core. 35-40mm 2:1 heat shrink should be about the right size.
Once your repair is complete secure the power cord to the motor frame with tie wraps for stress relief.
Good luck because this type of repair is pretty tough and unforgiving!!
Last edited by davefr; 03-02-2017 at 12:40 PM.
By buksam in forum Clock RepairReplies: 13Last Post: 09-27-2009, 04:16 PM
By VergeMan in forum Watch RepairReplies: 6Last Post: 04-02-2007, 01:44 PM
By schweige in forum Watch RepairReplies: 6Last Post: 02-12-2007, 02:24 AM
By schweige in forum Watch RepairReplies: 4Last Post: 05-17-2005, 02:02 AM
By bchaps in forum American Pocket WatchesReplies: 2Last Post: 08-03-2003, 11:12 PM