# Changing A Hamilton 505 Contact



## Silver Hawk

I'm really chuffed























Never thought I'd be able to do this







... change the contact wire on a Hamilton 505 balance









Here's the balance:










The bit that needs replacing is the tiny ?gold contact that is supported by the jewel on the staff --- not too clear in this photo, I'm afraid. The contact is attached to the green wire that goes off to the coil on one side of the balance --- top photo. Waxy glue holds the contact in place:










And how small are these contacts and wires. Bl**dy small! Here are five spare ones on a one penny piece:










I've just changed my first one...and the watch is running (







) ... I will see what the timekeeping is like after an overnight run....keeping my figures crossed









Cheers

Paul


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## Stan

Way to go Paul!









I'll keep my fingers crossed for you.


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## Silver Hawk

Stan said:


> Way to go Paul!
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Thanks Stan.









The contacts/wires were kindly given to me several years ago by Dan Mitchell in Essex. He is a close friend of Rene Rondeau, I believe.

At the time, he also offered to show me how to do all of this if I visisted him...which I still haven't done.....but I must email him and thank him again for the wires now that I have finally used one. He also does all sorts of Hamilton Electric conversions etc.

Paul


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## mach 0.0013137

Well done Paul























I can`t deal with things that small









My hands shake too much










I`d end up screaming in frustration


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## Roy

Well done Paul,


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## gravedodger

terrific job paul

you'll be fixing microchip tracks next


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## Silver Hawk

Stan said:


> Way to go Paul!
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You weren't keeping those fingers crossed Stan









Timekeeping is just as bad as before changing the worn contact --- gains about 5 mins in 24 hours, a common problem with worn out 505, so why hasn't it fixed it?
















Can someone tell me, I'm having a complete mental block, does shortening a hairspring make the watch run faster or slower? I should know this


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## pg tips

Bad news Paul. I wouldn't have thought hairspring length adjustment would reign in 5 mins would it?


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## Stan

I'm sorry to hear that Hawkey.









I did have them crossed and sent goodwill vibes but as usual, they didn't have any affect on machinery.









Hope you find a solution.


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## Silver Hawk

Well, I'm now in contact with Dan Mitchell and he has made some really useful suggestions that I would never have thought off:










_"The usual reason for a 505 running fast is a sticky _

"finger-block". If you look at the balance you will see a little

finger jutting out from the balance section part at opposite end from

hairspring. This is the finger block - it hits against a little pin

on the train bridge, to prevent balance overbanking. This sticks,

and is almost always the reason for fast running."

After cleaning, I asked him whether I should lighly oil the finger block?

_"NO - absolutely NOT - never ! It runs dry, and hopefully rustfree - _

holding the balance horizontal, the finger should always fall easily

vertical."










And what about cleaning a balance that has a coil attached:

_"If you can get 99% pure iso-propyl alcohol, use that instead, but not _

the usual 70% stuff which contains water.

Clean for a few minutes only - occasionally coils do fail in the

cleaner, alas - but seldom. I have spare balances if it did happen.

Some finger blocks never free up - my view is that there was never

enough clearance left here in the design.

Widen clearance between pins of regulator."

And when none of that make any difference














:

_"Send it to me -- I'll look at _

it/fix it for the return postage, (Â£5), and tell you what the trouble

was."

So I sent if off this morning!







Thank you Dan!


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## Stan

What a great bloke that Dan is.









Good news Paul.


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## pg tips

I like his style and his confidence.

Now don't go buying loads on the bay and sending them off for repair at a fiver a go will you.


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## Silver Hawk

Stan said:


> What a great bloke that Dan is.
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He certainly is







....watch is on its way back to me....plus....









_"Your Electric is on way back to you this morning - so should reach _

you Thurs.

Included are a few minor spares you might find a use for --

2 - NOS D pins, like you have bought, (long green wires).

2 - scrap D pins (short green wires on these two),

and a few scrap 505 balances -- on which to practice fitting D

pins.

More Z pins - most of my remaining stock - I just don't use them now

as D pins are easier for me to fit quickly.

Two 500 part movements - useful for screws and some train wheels -

but not all are interchangeable with 505s - the wheel on which the

canon pinion fits is not the same as the very similar one for the 505

which sits higher - but all screws are same, and the dialside parts.

Two old empty Nautilus steel cases - long since robbed of their

movements for other repairs - restorable if you find 2 x 505 movements.

Some of above are in tiny phials or wrapped in tins.

Ask if help needed with above.

Enjoy.

dan"


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## jasonm

What a gent, not many around nowdays









Present company accepted


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## Stan

There are some real heros out there.


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