Hamilton Pocket Watch - broken mainspring

[Folkvisor]

Hi

I am working on a Hamilton pocket watch with a broken mainspring. I am wondering how to measure the spring so that I can get a replacement.

I'd imagine length, width and perhaps thickness as well as barrel diameter.

Any help I can get is welcome. 

Dave

[StuartBaker104]

Hi Dave,

To save me posting the same thing again, see here. 

If you know the movement type, you can use the search tools on Cousins website, and they also have the GR catalogue scanned in there.

[WatchMaker]

You'll need the height, thickness and length of the spring plus the inside diameter of the mainspring barrel. 

Once you know this you can go to a site like Cousins UK (other parts suppliers are available!) to see if you can find a match: https://www.cousinsuk.com/category/mainsprings-by-size-watch-pocket

Mark has actually done a nice informative video available at: https://www.youtube.com/watch?v=CZfFkv0FLX4

 

Edit: Stuart ... we must have been writing a reply at pretty much the same time as yours only appeared once I'd posted mine! :-)

Edited April 28, 2017 by WatchMaker

[BUSAKAZ]

28 minutes ago, StuartBaker104 said:

Hi Dave,

To save me posting the same thing again, see here. 

If you know the movement type, you can use the search tools on Cousins website, and they also have the GR catalogue scanned in there.

If you put the model no or serial numbers down I will look in my book and give you all the dimensions.....

[Folkvisor]

Thank you all for your help.

I'll have a look at the Waltham reply.

It is a Hamilton 925 and I've found a short video regarding replacing the pallet fork but it would be nice if there was a complete strip-down video of it somewhere. I'm not sure how I should proceed with removing the balance assembly for one thing. The watch need to be dismantled so that it can be cleaned and lubricated.

Again, thank you for your help.

Dave

[Folkvisor]

Hi 

The serial # on the Hamilton 925 is: 238611 

I can get the inside measurement of the barrel too if you need it.

Thank you

Dave

[transporter]

Dave, if you have snags finding the exact size mainspring as I did on an old pocketwatch not so long ago I was given some advice of going abit smaller on different measurements of the spring, I will try to find the post as it was on this forum, basically I think I went a tad smaller on one measurement and although not the exact size works perfectly.

[StuartBaker104]

Jules Borel shows the original part and the GR generic...http://cgi.julesborel.com/cgi-bin/matcgi2?ref=HAM_925

 

[Folkvisor]

Good to know, thank you. As long as the T ends fit I guess the spring could be shorter.

I was wondering about lubricants as well. Would D5 and grease used for a wrist watch work? Can the train pivots be lubricated with 9020 or even 9010 and the pallet jewels/escape wheel with something even less viscous?  

I don't think the watch will be used every day so I don't think it'll get high wear. 

Dave

[StuartBaker104]

Dave,

There is a table in this link http://www.m-p.co.uk/muk/acrobat/hse/moebius-hs-sheets/moebius-specsbook.pdf which shows the recommendations from moebius, but many will have their own opinions on the topic.

The bhi lubrication guide is also helpful http://www.nawcc-index.net/Articles/BTI-The_Practical_Lubrication_of_Clocks_and_Watches.pdf

 

[StuartBaker104]

Oh, and this sticky thread... 

 

[Folkvisor]

Hi Stuart

Thank you for the links. Basically, the higher the friction the thicker the lubricant. 

I was told clock oil and grease should be used for pocket watches but I don't particularly like that idea.

Glad Valdbergsmassoafton!

Dave

[Folkvisor]

It's a bit tricky getting the pallet fork into the opening where it engages with the balance wheel.

I lucked out with all the other wheels. All the pivots went in their respective holes. One good thing is that there is lots of room to fiddle with things and I got a good tip regarding making a small forked tool with pegwood to guide the pivots.

I ordered the spring - just waiting for it. I look forward to having it going again.

Dave

[StuartBaker104]

Bit confused there... you should fit the pallet fork before the balance wheel.

I may be teaching grandma to suck eggs but... To be sure that everything is running freely, normally you would fit each wheel on its own and make sure it turns smoothly, then fit the train wheels together with the barrel. With one click on the mainspring you should see the train wheels turn freely and then recoil - again this tells you that everything is running freely. Then fit the pallet fork and give the mainspring a turn... the pallet should flick back and forth with a small nudge.  When you fit the balance, align the roller jewel with the pallet fork, then align the balance cock with its alignment pins. The balance should spring in to life and then you will know that you are not doing any dmaage as you tighten the balance cock screw. 

[Folkvisor]

Yup, the pallet fork works fine. I'm going to wait on putting the balance on until after I fit the spring; on order. It is pretty vulnerable sticking up the way it does.

[Folkvisor]

Also, this may not be a 925 because it is a bit different. Not sure about a number; no number is on the watch.

[Folkvisor]

There is a good video on YouTube re the Hamilton 925. There is a neat way of replacing the pallet fork in the video using painter's tape.

Just go to the YouTube site and put this suffix in after com.

I put it together the other way around because that's how someone taught me to do it. I think this is a good way to do it as well but both ways need a little patience lining things up.

/watch?v=81yo_cwdBkU

[dadistic]

On 5/2/2017 at 1:10 PM, Folkvisor said:

There is a good video on YouTube re the Hamilton 925. There is a neat way of replacing the pallet fork in the video using painter's tape.

Just go to the YouTube site and put this suffix in after com.

I put it together the other way around because that's how someone taught me to do it. I think this is a good way to do it as well but both ways need a little patience lining things up.

/watch?v=81yo_cwdBkU

I like the wooden screwdrivers he uses in the video  The other pegwood tools look handy, too.

[Folkvisor]

Yes, I made a pegwood screwdriver as well; since I was working on a friend's watch and didn't want to scratch it.

I also like the idea of backing off a screw until it clicks into place. I've always done that with screws that go into wood on a piano but I've never done it on a watch. I think it's a good idea for larger screws but, with screws as big as a speck of dust, I'm just glad to get them in...

I'm still waiting for a mainspring for it but the watch works if you put pressure on the wheel so I just hope I can fit a new mainspring without incident. I've never done it before...

[BUSAKAZ]

On ‎28‎/‎04‎/‎2017 at 6:45 PM, Folkvisor said:

Hi

I am working on a Hamilton pocket watch with a broken mainspring. I am wondering how to measure the spring so that I can get a replacement.

I'd imagine length, width and perhaps thickness as well as barrel diameter.

Any help I can get is welcome. 

Dave

sorry Dave for taking so long but I have been away

 

is this any use to you

cheers kaz

[Folkvisor]

Hi

Thank you for this. I've ordered a spring - hopefully it fits.

Dave

[BUSAKAZ]

8 minutes ago, Folkvisor said:

Hi

Thank you for this. I've ordered a spring - hopefully it fits.

Dave

No problem 

[Folkvisor]

I got the spring but the cleat on the barrel arbour is being stubborn about grabbing the end of the spring. I am bending the spring slightly so it will 'hug' the arbour and I think I've almost got it convinced.

Also, it looks like I may need to file the hole in the top plate of the barrel a little so that the T will fit better. 

Replacing the barrel wheel is going to be fun too...

Always something but never boring.