Replacement of Impulse Jewel on 1895 Elgin

[jdrichard]

I just got an 18S 7j 1985 produced Elgin Pocket Watch. The Mainspring was fully wound and the balance was spinning free. I released the Mainspring with a bench key and inserting a small screwdriver into a hole near the winding mechanism. This worked bit when I removes the Balance cock, I found that the impulse jewel was broken.

Now I need to remove the roller table and then remove the jewel and shellac in a new one. I will document the process with updates under this topic. Let's hope for success.

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[sperki77]

Looking forward to your updates... I'm sure you will be successful.

[jdrichard]

Looking forward to your updates... I'm sure you will be successful.

Thanks. Should be fun.


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[oldhippy]

Not the easiest of repairs. Make sure you have the right type/shape of impulse pin, you will know what I mean when the old has been removed and the hole is nice and clean, careful with the length, you need it to engage in the pallet fork but you don't want it dragging. Good luck and keep us posted with your progress.   

[jdrichard]

Not the easiest of repairs. Make sure you have the right type/shape of impulse pin, you will know what I mean when the old has been removed and the hole is nice and clean, careful with the length, you need it to engage in the pallet fork but you don't want it dragging. Good luck and keep us posted with your progress.   

Any tips on determining the length?

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[jdrichard]

Step 1 - Set up Roller Table Remover tool

Step 2. - Remove Hairspring

Step3 - Place Roller Table with Balance onto tool

Step 4 - Tighten tool onto Balance staff and align Stake over pivot (critical not to damage pivot)
Step 5 - TAP out stake and balance leaving Roller Table behind

Step 6 - Place Roller Table into Combination tool and heat to loosen old broken jewel in old shellac.

Step 7 - Clean Roller/Impulse Jewel hole in Table
Step 8 - Using Vigorous Roller Jewel Gauge, measure size of palate fork opening (was 0.46)



Step 9 - Measure Gauge (just in case)
Step 10 - Order Jewel (or find)
More to follow........


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[oldhippy]

13 hours ago, jdrichard said:

Step 1 - Set up Roller Table Remover tool

Step 2. - Remove Hairspring

Step3 - Place Roller Table with Balance onto tool

Step 4 - Tighten tool onto Balance staff and align Stake over pivot (critical not to damage pivot)
Step 5 - TAP out stake and balance leaving Roller Table behind

Step 6 - Place Roller Table into Combination tool and heat to loosen old broken jewel in old shellac.

Step 7 - Clean Roller/Impulse Jewel hole in Table
Step 8 - Using Vigorous Roller Jewel Gauge, measure size of palate fork opening (was 0.46)



Step 9 - Measure Gauge (just in case)
Step 10 - Order Jewel (or find)
More to follow........


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Excellent walk through. I can't do better than that

[atimegoneby]

Hi  jdrichard

if the fork opening was 0.46 I just wondered what size jewel you would fit ?

P.S. I like the zippo lighter working as a spirit lamp !

nice job 

[Michael]

excellent job  .... looking forward to next installment

[jdrichard]

Excellent walk through. I can't do better than that

Thanks man. Getting more experienced:)


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[jdrichard]

Hi  jdrichard

if the fork opening was 0.46 I just wondered what size jewel you would fit ?

P.S. I like the zippo lighter working as a spirit lamp !

nice job  [emoji4]

I ordered a 46 given the gauge size was actually 0.467 and there was a smidgen if play when I placed the gauge into the fork. Hope I am good.


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[94marconi]

Excellent write up as always jd.  How much play should there be between the pallet fork and the jewel? Could you measure the broken bit you removed from the roller table?

Love the digital mike...so much more finesse than the calipers.

Wife is going to Mexico next week and Xmas is done with so I look forward to my balance staff project. Your Posts have me chomping at the bit lol

Ron

[jdrichard]

Excellent write up as always jd. [emoji4] How much play should there be between the pallet fork and the jewel? Could you measure the broken bit you removed from the roller table?

Love the digital mike...so much more finesse than the calipers.

Wife is going to Mexico next week and Xmas is done with so I look forward to my balance staff project. Your Posts have me chomping at the bit lol

Ron

Usually if you measure a 0.46 gap you would order a 0.44 jewel. But my measuring gauge accounts for this and tells you the size to order. Last time I used a wire end to measure the fork gap because I did not have the tool.


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[oli]

Very interesting (and I also really like the use of the zippo lighter!)

[jdrichard]

Very interesting (and I also really like the use of the zippo lighter!)

Thanks. I use the lighter fluid to clean the Watches as well. Could not find a spirit lamp so had to improvise.


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[94marconi]

Not to stray off topic jd, but just a quick question. You have great lighting in your shots. Artificial or natural?

Also i have heard of D shaped impulse jewels is this the case of yours? and if so are they D shaped in the hole in the roller table or are they all round where they are shellacked into the table and D shaped or round above the table? The bit that was removed from the table was not sufficient to measure for diameter? or was it not a representation of the jewel size above the table. Or just not measurable? 

Of course any chance I get to use the tools I have collected and restored only adds to the hobby, which I am sure you will agree...

Ron
 

[jdrichard]

The jewel is D shaped and the hole is the table is round. This is normal for American pocket watches. I did not try to measure the jewel I removed. It was too small. Best to get a gauge and measure the fork opening. I have successfully changed a jewel in a 12S 21 Jewel Illinois pocket watch.



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[94marconi]

I suppose I could answer my own questions and look at my own project...My Waltham has a D shaped hole in the roller table contrary to jd's round hole. Would not a round hole be a weak point of the jewel? When you say this is normal for American pocket watches is my 1892 model an exception or are Walthams in general an exception. My 1883 model Waltham is in storage so I can not compare. Just curious...

Can't wait to see the shellac process of installing the new jewel 

 

[oldhippy]

That's why I mentioned in my previous post to make sure you have the right type, if the hole is round you need a round impulse pin, what was there before was wrong.

Edited January 9, 2017 by oldhippy

[jdrichard]

That's why I mentioned in my previous post to make sure you have the right type, if the hole is round you need a round impulse pin, what was there before was wrong.

I'm sure your correct, but try and find one.

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[Watchtime]

again amazing to see what knowledge is under the members,   JD

[jdrichard]

again amazing to see what knowledge is under the members,   JD

Thanks. I have used a D shaped jewel in a round hole before and have had no issues. The shellac fills the open space in the roller table hole. The geometry of the D shape impulse pin and the receiving palate fork opening is such that the back of a round impulse jewel would never touch the fork at ant time while traversing through the fork opening. Thoughts?

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[oldhippy]

Have yo ever heard the term fitting a round peg into a square hole.

[jdrichard]

Have yo ever heard the term fitting a round peg into a square hole.

Fitting half a round peg into a square hole. Do you have a source for round impulse jewels?


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[oldhippy]

Try here. https://www.cousinsuk.com/product/roller-impulse-pin-jewels-seitz