Timex Electric contact wire

[HectorLooi 233]

Attempting to produce a contact wire for my Timex Electric. I thinned down a piece of spring from a broken mainspring. It's getting a bit difficult to hold now.

[Tmuir 442]

Let us know how you get on as I'm guessing NOS parts for that would be non existant

[HectorLooi 233]

Will do. I'll get my nose to the grindstone as soon as Monday comes.

I've never seen any NOS Timex contact wires on ebay before. Occasionally a Hamilton one may turn up. There is only 1 person I know who has them.

[JerseyMo 544]

 I'll post some NOS contact wires on eBay latter today.  

[JerseyMo 544]

Contact Springs have been listed - 

[JerseyMo 544]

1 hour ago, JerseyMo said:

Contact Springs have been listed - 

I don't recall where I found the article as it was maybe 10 years ago at least but, try a search for  ' A $25 Retail Electric Watch: The Timex Model 40" by Henry B. Fried.

[HectorLooi 233]

It suddenly struck me that I could try rehardening the old contact wire instead of fabricating a new one. So that's what I did this morning. I heated it till red hot and did a water quench. Then I resoldered the old wire back on.

It's too early to say that it works. I put the watch back together and let it run for awhile.

[Shane 13]

This seems like a good place to ask this question.

I have seen from my recollection this (or very similar) Timex wire/contact assemblies manufactured in different colors.  Does any one know what significance if any the color would indicate?

PS.

Timex spent quite a bit of time ensuring that the force from flexing this wire did not concentrate at the solder joint causing inevitable failure.

Good luck.  I'm trying to fix one myself.  Keep us posted.

[HectorLooi 233]

So far I've only seen them in blue and green. I'm not sure if the color has any significance. 

But I have seen three variants of the contact wire. The normal blue one. Then the green one with a plastic extension that supports the contact wire somewhere midway along its length. And finally the one for the Q quart which has a break in the middle to connect to the quartz oscillator circuit. 

I've never seen a contact wire fail at the solder joint. Usually it fails due to metal fatigue.

Just an update on the contact wires that I've been trying to make. The one made from the old mainspring was magnetic. When I put the magnet back on, the wire deflected so much that it couldn't touch the contact pin on the balance.

As for the old wire that I rehardened, it worked fine for a couple of weeks then it broke. I probably hardened it too much and didn't temper it properly.

The next one I'm going to try is a nickel titanium wire. It's non magnetic and super elastic. It is impossible to solder NiTi, so I might have to spot weld it to a piece of metal that can be soldered first.

[Shane 13]

I came across these while digging around this evening.  I can't remember if these are the only colors I've seen or just what I have now. I am working on the contact in the foreground it has a bad solder joint, possibly from being handled too roughly.  The hairspring also needed to be reworked.  The reworked parts are not going back into my TimeZone but I would like to try and get the movement I stole the repair parts from ticking again.

I will pull these movements apart and get a better look at the contact assemblies in the near future.

Thanks.

[HectorLooi 233]

5 hours ago, Shane said:

I am working on the contact in the foreground it has a bad solder joint, possibly from being handled too roughly.

That's really strange. Solder joints usually fail when they are subjected to movement, strain or thermocycling. This joint shouldn't have experienced any of that. Could you get a really high magnification photo of the joint?

[JerseyMo 544]

Just for a tease --- here is my supply of replacements

[Shane 13]

This is the best I could manage with the tools on hand but seems to show a cold joint.  My microscope is not accessible at the moment.  Once the power stops flickering (Rural New England during a snow storm) and I find a good way to fixture it, I will try a low temperature silver solder past.

[HectorLooi 233]

Try putting a blob of rosin flux on the existing solder and quickly melt it with the tip of your soldering iron. It's best if you have a temperature controlled iron set to 225 - 250 °C. Make sure the tip is clean and well wetted with solder. Don't overheat it or the plastic may distort.

If the old solder does not melt and give a nice shiny joint, you will have to remove it with a solder sucker and use fresh solder. I prefer using the old stuff that contains lead. (60% Tin : 40% Lead) I simply hate lead free solder. 

Good luck. 

[Shane 13]

Resoldered the wire adding just a dot of silver solder past and a quick reheat.  The plastic should be Nylon so I wasn't overly concerned as long as it we out quickly.  Recurved the hairspring and it's up and running once again.  It now probably needs to be reregulated since it lost the 1.25mm of spring trapped under the retaining pin when the balance was wrenched out but I'll let it run until that happens.

HectorLooi, thanks the interaction.

JerseyMo, thanks for your input as well.  I sent you a private message.